A Decade of Development of Chromogenic Culture Media for ...CULTURE USING CHROMOGENIC MEDIA VERSUS MOLECULAR DIAGNOSTIC METHODS.....469 CONCLUSIONS ... remain undetected as mixtures

A Decade of Development ofChromogenic Culture Media for ClinicalMicrobiology in an Era of MolecularDiagnostics

John D. PerryMicrobiology Department, Freeman Hospital, Newcastle upon Tyne, UK

SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 449INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450CHROMOGENIC MEDIA FOR DETECTION OF SPECIFIC (NONENTERIC) PATHOGENS . 450

Candida spp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450Pseudomonas aeruginosa . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451Staphylococcus aureus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453Streptococcus agalactiae (Group B Streptococcus) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453Urinary Tract Pathogens. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455

CHROMOGENIC MEDIA FOR DETECTION OF ENTERIC PATHOGENS. . . . . . . . . . . . . . . . . . . . 456Clostridium difficile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 456Campylobacter spp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457Salmonella spp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458Shigella spp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 458Shiga Toxin-Producing Escherichia coli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459Vibrio spp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 460Yersinia enterocolitica . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 460

CHROMOGENIC MEDIA FOR DETECTION OF ANTIMICROBIAL-RESISTANTBACTERIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461

Methicillin-Resistant Staphylococcus aureus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461Vancomycin-Resistant Enterococci . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462Extended-Spectrum-�-Lactamase-Producing Enterobacteriaceae. . . . . . . . . . . . . . . . . . . . . . . . . 464Carbapenemase-Producing Enterobacteriaceae . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465Carbapenem-Resistant Acinetobacter spp. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467

IMPACT OF LABORATORY AUTOMATION ON THE USE OF CHROMOGENIC MEDIA . 468CULTURE USING CHROMOGENIC MEDIA VERSUS MOLECULAR DIAGNOSTIC

METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 469CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472ACKNOWLEDGMENTS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473AUTHOR BIO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 479

SUMMARY In the last 25 years, chromogenic culture media have found wide-spread application in diagnostic clinical microbiology. In the last decade, therange of media available to clinical laboratories has expanded greatly, allowingspecific detection of additional pathogens, including Pseudomonas aeruginosa, group Bstreptococci, Clostridium difficile, Campylobacter spp., and Yersinia enterocolitica. New me-dia have also been developed to screen for pathogens with acquired antimicrobial resis-tance, including vancomycin-resistant enterococci, carbapenem-resistant Acinetobacterspp., and Enterobacteriaceae with extended-spectrum �-lactamases and carbapenemases.This review seeks to explore the utility of chromogenic media in clinical microbiology,with particular attention given to media that have been commercialized in the last de-cade. The impact of laboratory automation and complementary technologies such asmatrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOFMS) is also assessed. Finally, the review also seeks to demarcate the role of chromogenicmedia in an era of molecular diagnostics.

Published 25 January 2017

Citation Perry JD. 2017. A decade ofdevelopment of chromogenic culture mediafor clinical microbiology in an era of moleculardiagnostics. Clin Microbiol Rev 30:449 – 479.https://doi.org/10.1128/CMR.00097-16.

© Crown copyright 2017. The government ofAustralia, Canada, or the UK (“the Crown”) ownsthe copyright interests of authors who aregovernment employees. The Crown Copyrightis not transferable.

Address correspondence [email protected].

REVIEW

crossm

April 2017 Volume 30 Issue 2 cmr.asm.org 449Clinical Microbiology Reviews

on April 9, 2021 by guest

http://cmr.asm

.org/D

ownloaded from

on A

pril 9, 2021 by guesthttp://cm

r.asm.org/

Dow

nloaded from


http://cmr.asm

.org/D

ownloaded from

https://doi.org/10.1128/CMR.00097-16

https://doi.org/10.1128/ASMCrownCopyrightv1

mailto:[email protected]

http://crossmark.crossref.org/dialog/?doi=10.1128/CMR.00097-16&domain=pdf&date_stamp=2017-1-25

http://cmr.asm.org

http://cmr.asm.org/

http://cmr.asm.org/

http://cmr.asm.org/

KEYWORDS carbapenemase-producing Enterobacteriaceae, chromogenic media,methicillin-resistant Staphylococcus aureus, molecular methods

INTRODUCTION

Chromogenic media utilize synthetic chromogenic enzyme substrates in order tospecifically target pathogenic species (or groups of species) based on their enzyme

activity. Such enzyme activity is never completely species specific, necessitating the useof complementary enzyme substrates and/or selective agents. The majority of chro-mogenic media are therefore both selective and differential, accommodating theinhibition of nontarget organisms (e.g., using antibiotics or other inhibitors) andenabling target pathogens to grow as colored colonies due to their metabolism (usuallyby hydrolysis) of one or more chromogenic enzyme substrates. The fact that only targetpathogens should generate colonies of a particular color reduces the number ofcolonies that require investigation within a polymicrobial culture. Compared with theuse of conventional culture media, this often results in cost savings from reduced labortime and reduced use of reagents, as fewer biochemical and/or serological confirmationtests are required. This may contribute to quicker confirmation of pathogens andreduce the overall time required to issue a report. In some cases, discrimination oftarget pathogens from background flora due to generation of a specific color makespathogens less likely to be overlooked, thus improving rates of detection.

This review seeks to highlight the role of chromogenic culture media that have beenintroduced since 2006 and to summarize evaluation data that have been published inthe last decade for preexisting applications. The review aims to clarify any advantagesor disadvantages compared with conventional methods and assess the relative meritsof culture using chromogenic media and those of competing molecular tests, such astests based on PCR techniques. The impact of laboratory automation, including matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS)and methods for automated colony detection, is also discussed. The review is confinedto solid media that have been used for the isolation of clinically important bacteria fromhuman samples in published evaluations. The majority of the studies considered hereare peer-reviewed articles published in journals since 2006 in English, with prioritygiven to studies that utilize patient samples rather than pure microbial strains. Con-ference abstracts are cited sparingly and only when they offer additional insights. Since2006, the array of chromogenic culture media available to clinical laboratories hasexpanded, allowing the specific detection of many more pathogens of interest, such asClostridium difficile, Streptococcus agalactiae, Yersinia enterocolitica, Campylobacter spp.,and Pseudomonas aeruginosa. In addition, an expanded range of media is now com-mercially available to screen for bacteria with acquired mechanisms of antimicrobialresistance, including vancomycin-resistant enterococci (VRE), carbapenem-resistantAcinetobacter spp., and Enterobacteriaceae with extended-spectrum �-lactamases andcarbapenemases. Table 1 provides a timeline for the application of commerciallyavailable chromogenic media to clinical diagnostics (1–17).

CHROMOGENIC MEDIA FOR DETECTION OF SPECIFIC (NONENTERIC)PATHOGENSCandida spp.

A chromogenic medium for the identification and differentiation of pathogenicyeasts, CHROMagar Candida (CAC), was first reported in 1994 (2). As well as antibacterialagents, the medium incorporates two chromogenic substrates for the detection of�-hexosaminidase activity and phosphatase activity (18). The medium affords specificidentification of Candida albicans/Candida dubliniensis, which form green colonies dueto production of �-hexosaminidase, and Candida tropicalis, which forms blue coloniesdue to production of both enzymes. Other species of yeast form pink colonies due tophosphatase activity alone or produce neither of these enzymes and grow as whitecolonies. A range of commercially available chromogenic media has since been eval-uated, including Albicans ID (19), CandiSelect (19), Candida ID (20), Candida diagnostic

Perry Clinical Microbiology Reviews

April 2017 Volume 30 Issue 2 cmr.asm.org 450


http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

agar (21), Pourmedia Vi Candida (22), Chromogenic Candida agar (23), Brilliance Can-dida Agar (24) and HiCrome Candida differential agar (25). A common feature of thesemedia is a chromogenic substrate for �-hexosaminidase to discriminate C. albicans/C.dubliniensis from other yeasts, and most include a second chromogenic substrate(usually to detect phosphatase or �-glucosidase) to provide further discriminationbetween species (18). The main advantage of such chromogenic agars is their ability todetect mixed cultures of yeasts due to the fact that different species frequently formcolonies with different colors. Such mixtures of species may be indistinguishable andremain undetected as mixtures on conventional agars such as Sabouraud agar pluschloramphenicol (23, 26). This is important, as different species may have differentsusceptibilities to antifungal agents. While C. albicans/C. dubliniensis are usually sus-ceptible to antifungal agents, chromogenic media may help to detect species with ahigher likelihood of resistance to azoles and/or amphotericin B, including Candidakrusei, Candida glabrata, Candida rugosa and Candida inconspicua (27).

There have been relatively few comparisons of different chromogenic agars usingclinical specimens in the last decade. Ozcan et al. compared Oxoid ChromogenicCandida agar (OCCA) with CHROMagar Candida (CAC) and Sabouraud chloramphenicolagar (SCA) using 392 vaginal swabs. Yeasts were isolated from 161 samples, and 21samples (13%) yielded a mixture of species on at least one medium (23). OCCA and CACshowed comparable sensitivity (96.9% versus 97.5%, respectively) for detection ofpositive samples, whereas the sensitivity of SCA was lower (91.9%). For the 21 poly-fungal infections, 20 (95.2%) were detected using OCCA, compared with only 14(66.7%) using CAC (P � 0.05). Sendid et al. compared CandiSelect 4 (CS4) with CACusing 1,549 clinical samples from a wide variety of sites (28). A total of 502 samples(32.4%) yielded one or more yeast species, including 37 samples (7.4%) that yieldedmore than one species. The sensitivities of CS4 and CAC were very similar (92.1 and91.1%, respectively), with no false-positive results. CS4 was superior to CAC for pre-sumptive identification of C. glabrata (80 versus 75%) and C. krusei (92 versus 83%) butwas less effective for C. tropicalis (68 versus 76%).

Pseudomonas aeruginosa

P. aeruginosa is an important nosocomial pathogen and may also cause community-acquired infections, particularly in individuals with underlying disease. For example, inpatients with cystic fibrosis, it is a common and important cause of respiratory tractinfection. Laine et al. reported the first chromogenic medium designed specifically forthe isolation of P. aeruginosa (PS-ID), which was subsequently commercialized as

TABLE 1 Timeline of the evolution of chromogenic culture media applied to clinicaldiagnostics

Yr of first reported studywith clinical samples Targeted pathogen(s) Reference

1993 Salmonella spp. 11994 Candida spp. 21995 Urinary tract pathogens 32000 Staphylococcus aureus 4

Methicillin-resistant Staphylococcus aureus 52006 Streptococcus agalactiae 62007 Enterobacteriaceae with extended-spectrum

�-lactamases7

Vancomycin-resistant enterococci 82008 Enterobacteriaceae with carbapenemases 92009 Acinetobacter spp. 10

Pseudomonas aeruginosa 11Shiga toxin-producing E. coli 12

2010 Clostridium difficile 132011 Campylobacter spp. 14

Vibrio spp. 152012 Shigella spp. 162013 Yersinia enterocolitica 17

Chromogenic Media for Clinical Microbiology Clinical Microbiology Reviews



http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

chromID Pseudomonas (11). The medium is notable as it is the first chromogenicmedium to utilize a chromogenic substrate for peptidase activity. This substrate,�-alanyl pentylresorufamine, is hydrolyzed by a �-alanyl aminopeptidase produced byP. aeruginosa, resulting in the formation of purple colonies (29) (Fig. 1a). The mediumwas evaluated with 100 sputum samples from patients with cystic fibrosis and com-pared with Pseudomonas CN selective agar (CN). The recovery of P. aeruginosa wasequivalent on both media (95.2%), but the positive predictive value of PS-ID (98.3%)was significantly higher than that of growth on CN (88.5%) for identification of P.aeruginosa (P � 0.05). Other species of Gram-negative bacteria were occasionally

FIG 1 Examples of chromogenic media for detection of specific pathogens that have been first reportedin the last decade. (a) Colony variants of Pseudomonas aeruginosa isolated from the sputum of a patientwith cystic fibrosis after 36 h of incubation on chromID P. aeruginosa (reprinted from reference 11 withpermission). (b) Dark blue colonies of Streptococcus agalactiae mixed with pink colonies of Enterococcusfaecalis after 18 h of incubation on StrepBSelect. (c) Typical colonies of Clostridium difficile after 48 h ofincubation on chromID C. difficile. (d) Red colonies of Campylobacter jejuni on CASA medium after 48 hof incubation. (e) Mauve colonies of a pathogenic biovar of Yersinia enterocolitica among blue colonies ofbackground flora on CHROMagar Y. enterocolitica. (f) Red colonies of Acinetobacter baumannii isolated onCHROMagar Acinetobacter (this medium has an optional supplement to select for carbapenem-resistantstrains). (Panels e and f are courtesy of CHROMagar, Paris, France; reproduced with permission.)




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

isolated as purple colonies on PS-ID, including Burkholderia cepacia complex (11). Thereare no other reports of this medium with clinical samples; however, Weiser et al.included chromID Pseudomonas in a comparison of five selective media that werechallenged with 50 isolates of P. aeruginosa and 90 isolates belonging to closely relatedspecies (30). chromID Pseudomonas showed the highest specificity of the five mediatested, but the authors reported that its sensitivity (95%) was negatively impacted bythe large variation in color of P. aeruginosa colonies (including pink-brown and green,possibly due to interference from natural pigments of P. aeruginosa). In conclusion,there is a lack of any published studies with clinical samples that demonstrate a higherrecovery of P. aeruginosa using chromogenic media.

Staphylococcus aureus

S. aureus is one of the most frequent and important human pathogens and isimplicated in a range of infections, including superficial skin infections, abscesses,bacteremia, and food poisoning. It is frequently found colonizing the nose, throat, andskin without causing symptoms. The first chromogenic medium for the isolation of S.aureus, CHROMagar S. aureus, was reported in 2000 (4) and utilized a phosphatasesubstrate for detection of S. aureus as pink colonies (18). Since that first report, at leasttwo other media have been made commercially available and evaluated with clinicalsamples, including S. aureus ID (31) (later commercialized as chromID S. aureus) andSaSelect (32). An alternative approach is utilized in chromID S. aureus, which relies uponproduction of �-glucosidase by S. aureus, resulting in the formation of green colonies.Each of these media has been reported to show sensitivity that is equivalent to orhigher than that of conventional nonselective media (e.g., blood agar), and, due to theincorporation of selective agents for the inhibition of nonstaphylococci, they areparticularly useful for specimens that yield a polymicrobial flora that includes Gram-negative bacteria. They also have high specificity (�90%) for detection of S. aureus,meaning that fewer confirmation tests are required when reading culture plates (4,31–34). The sensitivity may be increased if incubation is extended to 48 h, particularlyfor CHROMagar S. aureus (31, 33), but this is offset by a small decrease in specificity dueto other species forming colonies of the same color as S. aureus (31, 33, 34). As thereis only one published “head-to-head” comparison of these chromogenic media withclinical samples (31), there are insufficient data to conclude whether any particularchromogenic medium is better than another.

Streptococcus agalactiae (Group B Streptococcus)

Infections caused by group B streptococci (GBS) are a leading cause of morbidityand mortality in newborn infants. Asymptomatic carriage of GBS in the maternalgenitourinary tract may lead to colonization of the neonate, and in a small proportionof cases, this may lead to invasive disease. In an effort to reduce the burden of disease,authorities in many countries recommend universal screening of all pregnant womenfor vaginal/rectal colonization by GBS at 35 to 37 weeks of gestation (35). A widely usedstandard procedure involves overnight incubation of samples (i.e., vaginal/rectal swabs)in a selective enrichment broth followed by subculture onto blood-based culture mediafor investigation of typical hemolytic colonies (35). Granada medium is also widelyused, and this medium allows GBS to grow as orange colonies under anaerobicconditions due to formation of a natural pigment (36).

The first chromogenic medium for GBS (a prototype of chromID Strepto B) wasdescribed in 2006 (6). The medium allows GBS to form red colonies based on produc-tion of phosphatase. Other species either form colorless colonies or hydrolyze addi-tional chromogenic substrates (for esterase and �-cellobiosidase enzymes) to produceblue/green colonies (37). Since this first report, a large number of studies haveevaluated a range of chromogenic media for detection of GBS. Table 2 summarizes aselection of eight of these studies (i.e., those with the largest number of positivesamples). A number of studies have compared chromogenic media against selectiveblood-based agars (usually containing colistin and nalidixic acid) with or without the




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

use of a selective enrichment broth (38–44). When both types of media were testedunder the same conditions, chromogenic media showed a higher sensitivity thanselective blood agars in all of these studies. Most studies show that the sensitivity of anyculture medium for detection of GBS may be substantially improved by use of anenrichment broth (38, 39, 41, 44, 45). Chromogenic media have a potential advantageover Granada medium, as they do not require anaerobic incubation and have the abilityto detect nonhemolytic strains of GBS that typically fail to produce pigment on Granadamedium. Such strains are thought to account for up to 5% of invasive infections (46).Despite this, several studies have compared Granada medium with chromogenic agars(6, 40, 45–48), and overall there is no clear advantage of either in terms of sensitivity.Moreover, Granada medium invariably demonstrates 100% specificity and is arguablythe only medium that can be used without the need to confirm the identification ofsuspect colonies of GBS (46).

Only a few studies have compared the performance of different chromogenic mediafor GBS in a head-to-head evaluation using clinical samples (46, 48, 49). No statisticallysignificant advantage was found for any of the media tested, and sensitivity is likely tohave been underestimated because they were not used in conjunction with an enrich-ment broth (38, 44, 45). Most studies conclude that chromogenic media for GBS arehighly convenient tools that offer an increased sensitivity and specificity over conven-tional blood-based media. Further large studies would be needed to establish thesuperiority of any particular chromogenic medium, and the use of an enrichment brothshould ideally be included in such studies.

TABLE 2 Summary of studies evaluating chromogenic media for the isolation of Streptococcus agalactiae from clinical samples

Study authors,yr (reference)

Total no. ofsamples/no.positive Swab type(s) Test medium(a)a

Sensitivity (%)at:

Specificity (%)at:

Positivepredictive value(%) at:

18–24 h 48 h 18–24 h 48 h 18–24 h 48 h

Smith et al.,2008 (38)

200/83 Vaginal chromID Strepto B 67.5 67.5 100 100CNA blood agar 57 57 89.7 89.7Broth (CN-TH), chromID Strepto B 91.6 92.8 100 100Broth (CN-TH), blood agar 88 89.2 88.9 89.7

Craven et al.,2010 (39)

250/81 Vaginal, rectal chromID Strepto B 87.7 97.6Neo/nali blood agar 79 97.6Broth (CN-TH)/blood agar 91.4 100

Louie et al.,2010 (41)

1,025/243 Vaginal, rectal CNA blood agar 82.7Broth, CNA blood agar 92.2Broth, StrepB Select 98.8 99.2

Joubrel et al.,2014 (46)

141/88 Vaginal Granada 96.5 100Brilliance GBS 94.3 96.2StrepB Select 97.7 91chromID Strepto B 92 92 98.7

Poisson et al.,2010 (47)

528/60 Vaginal, others chromID Strepto B 71.7 90 100 85.7Granada 61.7 88.3 100 100Blood agar 46.7 66.7 82.4 88.9

Poisson et al.,2011 (42)

285/84 Vaginal, rectal Broth (CN-TH), CHROMagar StrepB 79 92 96 95Broth (CN-TH), CNA blood agar 82 92Broth (CN-TH), blood agar 40 58 92 91

Kwatra et al.,2013 (43)

260/92 Vaginal, rectal CHROMagar StrepB 85.9 88CNA blood agar 70.7 80.9Broth (GN-TH), blood agar 55.4 78.4

Morita et al.,2014 (37)

1,425/319 Vaginal, rectal Broth (CN-TH), chromID Strepto B 99.7Broth (CN-TH), blood agar 93.7

aCNA blood agar, blood agar supplemented with colistin and nalidixic acid; broth (CN-TH), Todd-Hewitt broth supplemented with colistin and nalidixic acid; neo/naliblood agar, blood agar supplemented with neomycin and nalidixic acid; broth (GN-TH), Todd-Hewitt broth supplemented with gentamicin and nalidixic acid.




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

Urinary Tract Pathogens

The first report of a chromogenic medium for diagnosis of urinary tract infectionsdescribed an evaluation of CPS ID2 in 1995 (3). This medium exploited a substrate for�-glucuronidase to allow the specific identification of the most common urinary pathogen,Escherichia coli, as pink or red colonies. An additional substrate for �-glucosidase allowsdetection of enterococci as small green colonies and the Klebsiella-Enterobacter-Serratia(KES) group as larger green colonies. Finally, the inclusion of tryptophan and iron saltsallows Proteeae (Proteus-Providencia-Morganella) to form brown colonies due to deaminaseactivity (50).

A range of other media has since been commercialized and evaluated with clinicalsamples, including CHROMagar Orientation (51), UriSelect medium (52), Rainbow AgarUTI medium (52), Chromogenic UTI medium (52), USA agar (53), Harlequin CLED (54),and Urichrom agar (55). A number of these media, including CHROMagar Orientation,UriSelect medium, and Chromogenic UTI medium, utilize a substrate for �-galactosidasefor detection of E. coli (18). This allows the direct identification of a higher proportionof E. coli isolates, as approximately 99% of E. coli isolates produce �-galactosidase,compared with approximately 94% that produce �-glucuronidase (18). However, thisadvantage is offset by a small decrease in specificity due to the misidentification of aproportion of Citrobacter spp. as E. coli in some reports (56, 57). This small decrease inspecificity can be largely eliminated by inclusion of a spot indole test, but this islaborious as it needs be applied to all colonies resembling E. coli (56).

In some studies, chromogenic media have been shown to provide a superiordifferentiation of mixed cultures due to the fact that different species may generatecolonies with different colors and may not be easily differentiated on conventionalagars. This can assist in the recognition of urine samples that may be contaminated,particularly compared with culture on cystine-lactose-electrolyte-deficient (CLED) agar(54, 56). However, this advantage is not apparent in other studies (58, 59). A consistentadvantage of chromogenic media is their ability to identify E. coli and provide identi-fication of other groups of species (KES and Proteeae). Several groups have shown howthat can contribute to a decrease in workload for species identification and/or to costsavings to the laboratory (60–62); however, this may have no significant impact on theoverall time taken to generate a final report (62).

Chromogenic media designed for detection of urinary tract infections are uniqueamong chromogenic media as they do not contain antimicrobials as selective agents inorder to cultivate as many species as possible. They can therefore potentially be usedas single media for the culture of urine samples. In one of the largest reported studies,Aspevall et al. (58) evaluated four chromogenic media, i.e., Chromogenic UTI medium,CHROMagar Orientation from two commercial sources, and CPS ID2, alongside cultureon CLED, blood agar, and MacConkey agar using 1,200 urine samples. Althoughincubation was extended for up to 48 h, this had a minimal impact on any of the testmedia. A total of 420 isolates deemed to be potentially significant were recovered from379 urine samples at a count of �104 CFU/ml. A total of 96% of these isolates wererecovered on blood agar and also on CLED agar. The four chromogenic media recov-ered between 92 and 96% of isolates. The authors concluded that any of the chromo-genic media studied could be used as a single medium for the isolation of uropatho-gens. The authors also reported that mixed urethral flora was easier to detect on bloodagar due to better growth of fastidious species such as corynebacteria and alpha-hemolytic streptococci. They therefore advocated retaining blood agar as part of theurine culture workup, as isolation and discrimination of different Gram-positive bacte-rial species were found to be much easier with this medium. This has been noted byothers; for example, Yarbrough et al. (62) noted the recovery of a smaller amount ofperiurethral flora (including lactobacilli and group B streptococci) on chromID CPS Elitethan with culture on blood agar. This resulted in fewer reports of contaminated orinsignificant growth. The authors concluded that chromID CPS Elite agar may be a




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

feasible alternative to conventional media for isolation and identification of mostcommon uropathogens in urine specimens.

Some brands of media have been subject to incremental improvements over the yearsand new generations of media have been commercialized. In the last decade, four pub-lished studies have compared either UriSelect 4 or CHROMagar Orientation with differentgenerations of CPS media (CPS ID3, CPS ID4, and chromID CPS Elite). The studies revealedonly minor differences in specificity between these media, with sensitivity reported to bebroadly equivalent (57, 59, 63, 64). Data are lacking on the effectiveness of chromogenicmedia for recovery of some fastidious Gram-positive bacteria, some of which (e.g., Aero-coccus urinae) have been implicated as human pathogens (63, 65).

CHROMOGENIC MEDIA FOR DETECTION OF ENTERIC PATHOGENSClostridium difficile

Over the last decade there has been renewed interest in the culture of stool samplesfor the isolation of C. difficile. One reason is the emergence of so-called hypervirulentstrains that cause outbreaks of C. difficile infection (CDI) that are associated with anincreased severity of disease and significant mortality (66). In order to track the spreadof such strains, it is usually necessary to isolate them by culture and perform moleculartyping. Culture also affords a very high sensitivity for detection of C. difficile and maytherefore be useful in the diagnosis of CDI. In one large 7-year study, toxigenic cultureresulted in the diagnosis of 355 cases of CDI that would have been missed using thefecal cytotoxin assay alone (67). For these reasons, isolation of C. difficile followed bydemonstration of toxin or toxin genes (“cytotoxigenic culture”) is accepted by many asa “gold standard” for diagnosis of CDI (68).

The first chromogenic culture medium (IDCd) for isolation of C. difficile was reportedin 2010 (13). The principle was based upon the ability of C. difficile to generate blackcolonies due to expression of �-glucosidase activity resulting in the hydrolysis of achromogenic substrate (Fig. 1c). The authors reported that IDCd offered effectiveisolation of C. difficile within only 24 h of incubation with or without the use of alcoholshock treatment, in contrast to other selective media. IDCd was subsequently commer-cialized and marketed as chromID C. difficile. Since this first report, at least six publishedarticles have reported evaluation data for chromID C. difficile in comparison with othermedia (69–74). Five of these studies are summarized in Table 3. In all cases, chromID C.difficile showed a sensitivity superior to that of comparator media and resulted ingreater inhibition of other flora. In three of these studies, there was evidence thatincubation of chromID C. difficile for 48 h improved the sensitivity of the medium,particularly for clinical samples with a low burden of C. difficile. In a further study,chromID C. difficile and Oxoid Clostridium difficile selective agar (CCFA) were used forthe culture of 686 stool samples from 508 patients in four hospitals in Hong Kong, withincubation of both media for up to 72 h (74). C. difficile was isolated from 118 stoolsamples using chromID C. difficile, compared with 70 stool samples using CCFA (P �

0.001); however, the overall sensitivity of the two media was not reported.The high sensitivity afforded by chromID C. difficile is due to a combination of high

selectivity against unwanted bacteria and a strong propensity of the medium tostimulate germination of spores (13). These attributes were exploited by Hill et al., whodemonstrated the superior sensitivity of chromID C. difficile for recovery of C. difficilefrom environmental surfaces (75). In a study with 496 samples from the hospitalenvironment, the sensitivity of chromID C. difficile was 87.6%, compared with asensitivity of 26.6% for cefoxitin-cycloserine-egg yolk agar plus lysozyme, a mediumthat has also been recommended for environmental screening (P � 0.0001) (76).

Despite the high sensitivity of chromID C. difficile, the medium also has somelimitations. The chromogenic reaction is not specific for C. difficile, and black coloniesmay be produced by other anaerobic species, most notably Clostridium hathewayi (aspecies previously classified as Clostridium clostridioforme) (74). Colonies recovered onchromID C. difficile therefore require identification, and this can be readily achievedusing MALDI-TOF MS (74). Alternatively, Park et al. proposed the use of a Gram stain




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

plus a simple disk test for pyroglutamyl aminopeptidase, and this may be useful forlaboratories without access to MALDI-TOF MS (77). Furthermore, a subset of C. difficilestrains fails to generate black colonies due to the absence of the �-glucosidase gene,and this appears to be a consistent feature of strains of ribotype 023 (78, 79). In a UKstudy, the proportion of isolates failing to generate black or gray colonies within 48 hwas reported to be 1.6% (13). Such isolates may still be detected on chromID C. difficiledue to their characteristic colony shape, but care must be taken to ensure that suchcolonies are not overlooked.

It is worth emphasizing that culture of C. difficile alone has little predictive value fordiagnosis of CDI without subsequent demonstration of the isolate’s ability to producecytotoxin. This can be directly demonstrated by testing culture supernatants on celllines or may be inferred much more rapidly by testing colonies for toxin genes by PCR(80). Darkoh et al. claimed that they circumvented this problem with the report of anew chromogenic medium (the Cdifftox plate assay) on which toxigenic C. difficileisolates formed blue colonies, thus differentiating them from nontoxigenic isolates,which formed white colonies (81). This was achieved using 5-bromo-4-chloro-3-indolyl-�-D-galactopyranoside (X-Gal) for detection of the glycosyltransferase activity of toxinsA and B. Despite its promise, I am not aware of any published evaluation data for thismedium since it was first described in 2011 (81).

Campylobacter spp.

Campylobacter spp. are the most common bacterial cause of gastroenteritis (GI) inmany countries, and infection is primarily due to ingestion of contaminated food. CASA(Fig. 1d) is a chromogenic medium initially designed for the isolation of Campylobacterspp. from food, but it has since been evaluated with stool samples from patients withsuspected gastroenteritis. The chromogenic substrate used for detection of Campylo-bacter spp. is undisclosed by the manufacturer. Le Bars et al. compared CASA with twononchromogenic agars (Karmali medium and Campylosel) for the isolation of Campy-lobacter spp. from 370 diarrheic stool samples (14). Cultures on all three media wereincubated for up to 96 h in a microaerophilic atmosphere at two different temperatures,37°C and 42°C. The sensitivity of CASA was equivalent to or slightly better than thatshown by either of the other two media, but CASA was reported to be much moreselective, which led to a reduction in the time required for processing colonies for

TABLE 3 Summary of studies comparing chromID C. difficile with other culture media forisolation of C. difficile from stool samples.

Study authors, yr(reference)

Total no. ofsamples/no. positive

Sampletreatment Test mediuma

Sensitivity(%) at:

24 h 48 h

Eckert et al., 2013 (70) 406/54 None chromID C. difficile 74.1 87TCCA 85.2CLO 70.4

Carson et al., 2013 (69) 50/47 None chromID C. difficile 100TCCFA 87

100/96 Alcohol chromID C. difficile 99TCCFA 96

Shin and Lee, 2014 (72) 530/180 Alcohol chromID C. difficile 55.6 85CDSA 19.4 75.6

Yang et al., 2014 (73) 289/49 None chromID C. difficile 93.9 98CCFA 18.4 30.6

Han et al., 2014 (71) 185/36 Heat chromID C. difficile 58.3 100CDSA 83.3

aTCCA, brain heart infusion agar plus 5% blood, taurocholate, cycloserine, and cefoxitin; CLO, Clostridiumdifficile agar (bioMérieux); TCCFA, cycloserine-cefoxitin-fructose-egg yolk agar (CCFA) plus 0.1%taurocholate; CDSA, C. difficile selective agar (BBL); CCFA, cycloserine-cefoxitin-fructose-egg yolk agar.




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

confirmation of Campylobacter. Dalziel et al. reported the culture of 979 stool sampleson CASA and modified charcoal-cefoperazone-deoxycholate agar (CCDA) with incuba-tion of cultures at 42°C for 36 to 48 h in a microaerophilic atmosphere (82). The authorsreported sensitivities of 100% and 84% for CASA and CCDA medium, respectively (P �

0.001), and also reported a higher selectivity of CASA. A limitation of CASA is the lackof a specific chromogenic reaction to indicate the presence of Campylobacter spp., asother species that grow on the medium also hydrolyze the chromogenic substrate toproduce pink or red colonies, and some may therefore appear quite similar to Campy-lobacter spp.

Salmonella spp.

Salmonella spp. remain one of the most important causes of foodborne gastroenteritis,and chromogenic media designed for the specific isolation of Salmonella spp. have beenavailable for at least 25 years. Rambach agar and SM-ID were the first two examples of suchmedia (1), and both have been superseded by new generations of media. The principles ofSalmonella detection exploited in these first generations of chromogenic media have beenpreviously reviewed (50). It has been consistently demonstrated that chromogenic mediado not offer a superior sensitivity to conventional agars such as xylose-lysine-deoxycholate(XLD) agar and Hektoen enteric agar (83, 84). Furthermore, in contrast to almost allchromogenic media, such conventional agars offer the opportunity to isolate both Salmo-nella and Shigella using a single culture medium. No single culture medium or combinationof media can preclude the necessity for enrichment of stool samples, e.g., in selenite broth,which is essential for detection of low numbers of Salmonella and significantly enhancesdetection (84). The sole advantage of chromogenic media for Salmonella is the significantlyhigher specificity they afford compared to conventional media. This means that fewerconfirmatory tests than with conventional media are required to investigate colonies ofother species that may resemble Salmonella. This can result in cost savings for laboratories;e.g., in one study, a saving of EUR 2.7 (approximately US$3) per sample by inclusion of achromogenic medium was projected (83).

Most of the chromogenic media for Salmonella that are currently marketed rely ondetection of a C8-esterase enzyme produced by Salmonella that is detected by inclu-sion of a chromogen linked to caprylic (octanoic) acid. Substrates for �-glucosidaseand/or �-galactosidase are included so that other coliforms generate a different color.Antibiotics such as cefsulodin and novobiocin may be included for the inhibition ofPseudomonas spp. and Proteus spp., respectively. Brilliance Salmonella agar incorporatesa “suicide substrate” or “Inhibigen” that is hydrolyzed by E. coli to release a toxicproduct, thus inhibiting its growth (P. Druggan, 21 March 2002, patent applicationWO0222785). Only two published studies in the last decade have compared chromo-genic media for the isolation of Salmonella (83, 84). The chromogenic media includedwere chromID Salmonella ELITE, BBL CHROMagar Salmonella, SM-ID2, and BrillianceSalmonella agar, and these were compared with conventional agars. Neither studyreported any significant difference between any of the media with respect to sensitivity,but the specificity of chromogenic media was significantly higher than that afforded byconventional agars.

In summary, the use of a conventional agar (e.g., XLD agar) is appropriate for directculture of stool samples, as it accommodates isolation of Shigella spp., and the evidencesuggests that sensitivity is at least equivalent to that of chromogenic media fordetection of Salmonella spp. The use of a chromogenic medium after enrichment inselenite broth is an attractive option to target Salmonella spp. with high specificity andconsequently reduce the number of colonies requiring investigation. There is no clearadvantage of any particular chromogenic medium for this purpose.

Shigella spp.

Shigella spp. produce few hydrolytic enzymes that provide useful differentiationfrom other bacteria, and that has restricted the development of chromogenic media fortheir detection. However, the observation that all species of Shigella produce




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

�-ribosidase has provided one alternative means of detection (85). HardyCHROM SS isthe only commercially available chromogenic medium allowing isolation of bothSalmonella and Shigella that has been evaluated with clinical samples. Hinde et al.evaluated this medium with 400 stool samples in comparison with conventionalMacConkey and Hektoen enteric agars (16). The authors reported a superior specificityfor HardyCHROM SS that allowed fewer colonies requiring investigation, and they alsoreported a shorter time to detection. However, since only one isolate of Shigella spp.was recovered during the study, further studies with larger numbers of positivesamples are essential.

Shiga Toxin-Producing Escherichia coli

Shiga toxin-producing E. coli (STEC) bacteria are a cause of foodborne gastroenteri-tis, hemorrhagic colitis, and hemolytic-uremic syndrome. Among STEC strains, Shigatoxin production was first associated with E. coli of serotype O157:H7, and it was notedthat such strains, unlike most other E. coli strains, failed to ferment sorbitol. This led tothe design of sorbitol MacConkey agar, which has become widely used by clinicallaboratories. This situation has become much more complicated, and STEC can befound within many other serotypes that together may account for as much STEC-associated disease as O157:H7 (86). The fact that many of these additional serotypestypically ferment sorbitol has severely limited the effectiveness of sorbitol MacConkeyagar for diagnosis of infection with STEC.

Recovery of STEC by culture is challenging due to a low density of organisms insome stool samples and the lack of consistent biochemical features among STECserotypes (87). Despite this, since the first report of Rainbow agar O157 in 1998 (88),chromogenic media have been commercialized for the detection of STEC. Most ofthese media have been designed primarily for isolation of E. coli O157:H7, includingCHROMagar O157, Colorex O157, and Rainbow O157, whereas CHROMagar STECallows for detection of a wider range of STEC serotypes (89). Most of these mediaare based on similar principles, relying on an inability of E. coli O157 to produce acidfrom sorbitol and/or rhamnose and a lack of �-glucuronidase activity. A secondchromogenic substrate (e.g., for �- or �-galactosidase) may be used to highlight thepresence of E. coli O157:H7 among nonreactive background flora (18).

There have been six published evaluations of these media with clinical samples overthe last decade. Grys et al. tested 204 stool samples using PCR for detection of toxingenes and by direct culture on CHROMagar O157; only four positive samples werefound (all positive by PCR), and three of these were detected by culture (12). Hironvenet al. tested 47 fecal samples from patients with hemorrhagic diarrhea by plating onCHROMagar STEC and using an immunochromatographic assay for O157 antigen andShiga toxin. The chromogenic medium detected STEC in 16 positive samples, comparedwith only 14 detected by the immunoassay (90). Wylie et al. compared direct culture onCHROMagar STEC with a standard cytotoxin assay using 205 fecal samples (86). Therewere 14 positive samples, and the sensitivity and specificity of CHROMagar STEC werereported as 85.7% and 95.8%, respectively. Gouali et al. cultured 329 stool samples ontoCHROMagar STEC and Drigalski agar after preenrichment of the samples in a nonse-lective broth. Colonies from Drigalski agar were harvested and tested by PCR for toxingenes (87). From 39 Shiga toxin-positive stool specimens, STEC was recovered as mauvecolonies from 32 samples (sensitivity, 82.1%). Forty-eight isolates of E. coli that were notfound to harbor toxin genes were recovered as mauve colonies on CHROMagar STEC.

McCallum et al. tested 282 fecal samples using PCR for toxin genes and culture oncefixime-tellurite-sorbitol MacConkey agar (CT-SMAC) and CHROMagar STEC (91). Onlysix positive samples were found, of which three were detected using CHROMagar STECand only one detected using CT-SMAC, whereas all six were positive using PCR. Finally,Zeylas et al. tested 536 samples using direct inoculation of CHROMagar STEC and a PCRtest for toxin genes following preenrichment in MacConkey broth (89). Thirteen sam-ples were found to be positive, and all were detected using PCR. Eleven (84.6%) were




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

detected by culture on CHROMagar STEC, and a further 68 false-positive colonies wererecovered, giving a low positive predictive value of 13.9%.

The available evidence suggests that chromogenic media for the detection of STECdo not have sufficient sensitivity or specificity to replace methods that directly detecttoxin or toxin genes in stool samples. Consequently most studies have concluded thatthe optimal use of such media is for the isolation of STEC from samples that aredetermined positive using more sensitive methods, e.g., PCR (86, 87, 89, 90).

Vibrio spp.

Media for the isolation of pathogenic Vibrio spp., which have been designedprimarily for screening food samples, have been evaluated for use with clinical samples(15, 92). CHROMagar Vibrio and chromID Vibrio both allow for the isolation anddifferentiation of the two most important pathogenic species, Vibrio cholerae and Vibrioparahaemolyticus, and accommodate isolation of other Vibrio species. The chromogenicsubstrates used in these media are undisclosed by the manufacturers. CHROMagarVibrio was compared with thiosulfate-citrate-bile salts-sucrose agar (TCBS) for theisolation of V. parahaemolyticus from 57 patients with suspected gastroenteritis whohad recently ingested seafood. After enrichment in alkaline peptone water, five con-firmed isolates of V. parahaemolyticus were recovered on CHROMagar Vibrio compared,with only one isolate on TCBS. There were no false positives on either medium (15).chromID Vibrio was evaluated against TCBS before and after enrichment in alkalinepeptone water using 28 fecal samples and 66 artificially “spiked” fecal samples. Therewas equivalent sensitivity of the two media for isolation of both V. cholerae and V.parahaemolyticus, but the specificity of chromID Vibrio was reported to be twice that ofTCBS (100% versus 50%) (92). Further studies are required with clinical samples,including studies in low-prevalence settings.

Yersinia enterocolitica

Y. enterocolitica is a foodborne pathogen and a cause of diarrhea and pseudoap-pendicitis. The most widely used conventional agar for detection of this pathogen instool samples is cefsulodin-irgasan-novobiocin (CIN) agar, which utilizes mannitolfermentation as a biochemical indicator for Y. enterocolitica. CIN agar is effective, but itsspecificity is limited as a number of other species of Enterobacteriaceae are able to growon the medium and ferment mannitol, thus also generating magenta colonies (e.g.,Serratia spp., Providencia spp., Klebsiella oxytoca, and Citrobacter freundii). Weagantdescribed the development of Yersinia enterocolitica chromogenic medium (YeCM)(93). This medium sought to improve on the specificity of CIN agar by utilizingcellobiose as the fermentable carbohydrate for detection of Y. enterocolitica and byincluding a chromogenic substrate for �-glucosidase, an enzyme that is produced bymost other species of Enterobacteriaceae that are able to grow on CIN agar (93). As wellas enabling differentiation of Y. enterocolitica from other species, this medium had theadditional advantage that only pathogenic types of Y. enterocolitica would be detected(as nonpathogenic biovars produce �-glucosidase). There are no reports of the use ofthis medium with human clinical samples, although YeCM was used in a later study thatexamined the presence of Y. enterocolitica in 900 tonsil swabs from pigs (94).

Renaud et al. described the use of CHROMagar Yersinia (CAY) (Fig. 1e) for theisolation of Y. enterocolitica from 1,494 stool samples from hospitalized patients andused CIN agar as a comparator (17). Although the composition of this medium isundisclosed, the medium achieves outcomes very similar to those obtained with YeCM,suggesting the inclusion of a substrate for �-glucosidase to increase specificity (95). Sixisolates of pathogenic Y. enterocolitica were successfully isolated using both CAY andCIN agar, but CAY showed a much higher specificity (99%) than CIN agar (90.4%), withonly 14 false-positive isolates recovered on CAY (P � 0.001). In contrast, 137 isolatesbelonging to other species (predominantly C. freundii and Providencia spp.) grew asfalse-positive colonies on CIN agar, and there was no differentiation between the sixpathogenic Y. enterocolitica isolates recovered and six additional nonpathogenic iso-




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

lates of biovar 1A on CIN agar. Another chromogenic agar, Yersinia Enterocolitica Agar(YECA), has been described, but its composition is undisclosed and there are no dataavailable for testing of human samples (96).

CHROMOGENIC MEDIA FOR DETECTION OF ANTIMICROBIAL-RESISTANTBACTERIA

Prior to 2006, chromogenic media were already available for the specific detec-tion of methicillin-resistant S. aureus (MRSA) (5). The last decade has seen anexpansion in the range of culture media developed specifically for the detection ofother antimicrobial-resistant bacteria. Between 2007 and 2009, chromogenic mediawere first reported for the detection of vancomycin-resistant enterococci (VRE) (8),Enterobacteriaceae with extended-spectrum �-lactamases (7) and carbapenemases(9), and carbapenem-resistant Acinetobacter spp. (10). Rapid and efficient detectionof these bacteria can allow for prompt decisions regarding the management ofcolonized patients in accordance with local infection control policies. Precautionssuch as isolation of colonized patients may limit the nosocomial transmission ofantibiotic-resistant bacteria between patients and within the hospital environment.

Methicillin-Resistant Staphylococcus aureus

MRSA strains exhibit resistance to most �-lactam antibiotics and frequently showresistance to other classes, such as macrolides and quinolones. MRSA is a significantnosocomial pathogen and has been implicated in numerous outbreaks of infection.Significant efforts have been made to control the spread of MRSA within the hospitalenvironment, and some authorities advocate universal screening of patients to identifythose who are asymptomatically colonized (97). A great deal of investment has there-fore focused on optimal diagnostic methods for MRSA, including chromogenic media.

Chromogenic media for MRSA evolved from media designed for detection of all S.aureus by the simple inclusion of an antimicrobial that inhibits methicillin-susceptibleisolates. The traditional agent of choice for this purpose was oxacillin, and this wasincorporated into CHROMagar S. aureus to create the first chromogenic medium fordetection of MRSA (5). Later studies demonstrated that cefoxitin was a superior optionfor selection of MRSA due to induction of methicillin resistance in isolates that showedheterogeneous expression of resistance (98). A range of chromogenic media has beencommercialized and evaluated with clinical samples, including CHROMagar MRSA (99),chromID MRSA (100), MRSASelect (101), MRSA-screen (100), Brilliance MRSA (102), andSpectra MRSA (103). Such media are widely used; for example, in an external qualityassessment exercise in 23 countries in Europe and in Israel, it was reported that 88% oflaboratories utilized a chromogenic medium alone to screen for MRSA (104).

A survey of the literature since 2006 reveals at least 60 publications that havecompared chromogenic media for MRSA with alternative methods using human clinicalsamples, and at least 25 of these include a head-to-head comparison of two or morechromogenic media. The conclusions of these studies are often conflicting, and ananalysis of the data is further confounded by the fact that certain brands of media havebeen the subject of incremental improvements to produce newer generations ofthese media. When assessing the performance of chromogenic media for MRSA, itis prudent to analyze studies that are recent and include large numbers of clinicalsamples (ideally �1,000 samples).

There is a general consensus that chromogenic media show greater sensitivity thanconventional agars such as mannitol salt agar plus oxacillin. The sensitivity of chromo-genic agars is increased by incubating plates for 48 h, at the expense of a decrease inspecificity. These observations are confirmed by a meta-analysis of 29 studies reportedbetween 2004 and 2008 (105). Table 4 summarizes the findings of the five largestevaluations published since 2010 that compare two or more chromogenic media usingclinical samples (106–110). From this selection of data and from the wider literature, itis difficult to conclude with any certainty that any particular chromogenic medium issuperior or inferior to its competitors. A number of studies have shown conclusively




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

that the use of broth enrichment prior to inoculation onto chromogenic agar cansignificantly increase the sensitivity of MRSA detection, and this is exemplified by twoof the studies in Table 4 (109, 110).

Vancomycin-Resistant Enterococci

chromID VRE was the first chromogenic medium reported for the isolation ofenterococci with acquired resistance to glycopeptides (e.g., vancomycin and teicopla-nin) (8). In six studies with stool samples or rectal swabs, chromID VRE was comparedwith bile-esculin agars (with or without azide) supplemented with vancomycin (8,111–115). Two of these studies reported a superior sensitivity of chromID VRE (8, 115),and the others reported equivalent sensitivity (111–114). A consistent advantage ofchromID VRE was its ability to differentiate between Enterococcus faecalis and Entero-coccus faecium. This is achieved by incorporating chromogenic substrates for detectionof �-glucosidase and �-galactosidase (18). chromID VRE also showed a higher speci-ficity, leading to a reduction in the number of confirmatory tests that were required forsuspect colonies. Five other chromogenic media, AES VRE agar (115), Brilliance VRE (Fig.2a) (116), CHROMagar VRE (117, 118), Spectra VRE (119–121), and VRESelect (122), havesince been evaluated against bile-esculin agars (with or without azide) supplementedwith vancomycin, in studies with stool samples or rectal swabs. In each of the eightcited studies, the chromogenic media offered higher sensitivity and specificity. Allexcept AES VRE agar provided differentiation of E. faecalis from E. faecium.

Relatively few studies have included head-to-head comparisons of chromogenicagars for the isolation of VRE from clinical samples (115, 123–125). CHROMagar VRE andchromID VRE were evaluated with 259 stool samples after an overnight enrichmentstep and a 48-h incubation period (123). The authors reported an identical sensitivity ofthe two media (98.2%) and an equivalent specificity. Suwantarat et al. performed a

TABLE 4 Summary of selected studies evaluating chromogenic media for the isolation of MRSA from patient samples


Total no. ofsamples/no. positive Sample type(s) Test medium

Sensitivity (%)at:

Specificity (%)at:

24 h 48 h 24 h 48 h

Yang et al.,2010 (106)

578/99 Nasal swabs MSA-Fxa 92.9 96 97.1 95.2MRSASelect 94.9 100 98.5 97.7MRSA-ID 90.9 99 98.1 97.9CHROMagar MRSA 91.9 99 99.5 99

Morris et al.,2012 (107)

6,035/147 Nasal, groin, axilla, andwound swabs

Brilliance MRSA 2 78.2 99.9chromID MRSA 93.2 99.8chromID MRSA 2 83.7 99.9Colorex MRSA 87.1 99.9

Denys et al.,2013 (108)

515/73 Nasal swabs BBL CHROMagar MRSA II 87.7 98.6MRSASelect 89 93.4Spectra MRSA 83.6 92.1

Veenemans et al.,2013 (109)

1,368/102 Nasal, throat, and rectalswabs

Direct inoculationBrilliance MRSA 2 65.7 99.8MRSA-ID 52 99.2

After broth enrichmentBrilliance MRSA 2 100 99.1MRSA-ID 98 98.7

Dodémont et al.,2015 (110)

1,220/107 Nasal, throat, perineal, andskin swabs

Direct inoculationBrilliance MRSA 2 60.7 72.9 99.7 97.9chromID MRSA 50.5 71 99.3 96.8chromID MRSA SMART 66.4 78.5 99 97.8

After broth enrichmentBrilliance MRSA 2 85 98.7chromID MRSA 87.9 99chromID MRSA SMART 86 97.8

aMSA-FX, mannitol salt agar plus 5 �g/ml cefoxitin.




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

large study that compared five chromogenic agars with bile-esculin-azide-vancomycinagar (BEAV) using 400 stool samples, of which 99 contained VRE (124). The chromo-genic media comprised InTray Colorex VRE, chromID VRE, VRESelect, HardyCHROM VRE,and Spectra VRE. The authors reported a significantly higher sensitivity (89.9 to 93.9%)of all chromogenic agars than of BEAV (84.8%) and also an earlier time to detection.chromID VRE showed the highest sensitivity of the five chromogenic agars, but this wasnot statistically significant. Four of the chromogenic agars showed identical specificity(99.7%), whereas the specificity of InTray Colorex VRE was lower (98.3%). Differenceswere noted among the chromogenic media with respect to time to detection, the needfor supplementary testing, and ease of color distinction among colonies, as well asnon-VRE breakthrough growth. Finally, Gouliouris et al. compared chromID VRE andBrilliance VRE for the isolation of VRE from 295 stool samples from nursing homeresidents (125). They reported an equivalent sensitivity of the two chromogenic mediaand noted that the sensitivity of both media was significantly improved by incubationfor 48 h and inclusion of a preenrichment step. The selectivity of Brilliance VRE washigher than that of chromID VRE.

In conclusion, chromogenic media for detection of VRE offer a sensitivity that isfrequently reported as better than that of conventional media such as BEAV. UnlikeBEAV, most chromogenic media allow differentiation and presumptive identification ofthe two dominant species of enterococci, and most reports note that less time isrequired for processing of colonies due to the higher selectivity/specificity of thesemedia. There is no clear difference in sensitivity among most of the chromogenic agarsreported here.

FIG 2 Examples of chromogenic media for detection of antimicrobial-resistant pathogens that have beenfirst reported in the last decade. (a) Purple colonies of Enterococcus faecium (vanB) and blue-greencolonies of Enterococcus faecalis (vanA) on Brilliance VRE agar. (b) ESBL-producing colonies of Klebsiellapneumoniae with SHV-36 and CTX-M-9 enzymes (green colonies) and Escherichia coli with CTX-M-9enzyme (pink/blue colonies) on Brilliance ESBL agar. (c) K. pneumoniae (green colonies) and E. coli (redcolonies), both with OXA-48 carbapenemase, isolated on chromID OXA 48. (d) Carbapenemase-producing K. pneumoniae with OXA-48 enzyme (blue colonies) and E. coli with NDM-1 enzyme (pinkcolonies) isolated on Colorex mSuperCarba medium.




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

Extended-Spectrum-�-Lactamase-Producing Enterobacteriaceae

Extended-spectrum �-lactamases (ESBLs) have become globally disseminated withinspecies of Enterobacteriaceae. These enzymes hydrolyze third-generation cephalosporins,typically conferring resistance to these agents, but are inhibited by clavulanic acid. Genesencoding ESBLs are frequently found on transmissible plasmids that often harbor otherresistance determinants (e.g., encoding resistance to aminoglycosides). Prompt and accu-rate detection of ESBL producers can assist in guiding optimal antimicrobial therapy (126)and limiting nosocomial transmission (127). The first published report of a chromogenicmedium for detection of ESBL producers described the evaluation of ESBL-Bx (a prototypeof chromID ESBL). The authors compared this new medium with MacConkey agar supple-mented with 2 �g/ml ceftazidime for the isolation of ESBL producers from 644 clinicalsamples (7). They reported a sensitivity of 97.7% for the chromogenic medium, comparedwith 84.1% for MacConkey agar plus ceftazidime. Since this first report, a range of chro-mogenic media has been made commercially available, and reports of their performanceare summarized in Table 5 (128–134). The principles of these media have much incommon. The media typically employ a combination of chromogenic substrates todetect �-galactosidase (or �-glucuronidase) production by E. coli and �-glucosidaseproduction by the KES group. This allows detection and differentiation of the mainspecies or groups associated with ESBL production. A cephalosporin is incorporatedto inhibit susceptible strains, and other inhibitors may be included to inhibit thegrowth of Gram-positive bacteria and yeasts. Enterobacteriaceae with AmpC�-lactamase are frequently isolated on all of these media, and to a large degree thisaccounts for the relatively low positive predictive values shown in Table 5 (133).

Five of the studies in Table 5 include a direct comparison of two or more chromo-genic media, and no significant difference in sensitivity was reported after 24 h of

TABLE 5 Summary of studies evaluating chromogenic media for the isolation of Enterobacteriaceae with extended-spectrum-�-lactamasesfrom clinical samples


Total no. ofsamples/no. positive Sample type(s) (n) Test medium

Sensitivity (%)at:

Positivepredictive value(%) at:

18–24 h 48 h 18–24 h 48 h

Réglier-Poupet et al.,2008 (128)

765/33 Rectal swab (468), urine(255), respiratory (42)

chromID ESBL 88 94 39 28BLSE 85 85 15 11

Huang et al.,2010 (129)

528/59 Fecal (344), respiratory (134),miscellaneous (50)

chromID ESBL 94.9 48.7Brilliance ESBL 94.9 46.7MAC with ceftazidime disk 74.6 64.7

Paniagua et al.,2010 (130)

500/41 Stool (500) chromID ESBL 100 63MAC � 1 �g/ml CAZ plus

MAC � 1 �g/ml CTX87.8 43.4

Saito et al.,2010 (131)

256/17 Stool (186), urine (48), other(22)

chromID ESBL 88.2 46.9CHROMagar ESBL 100 51.5

Willems et al.,2013 (132)

139/16 Perineal and nasal swabs(139)

chromID ESBL 81.2 87.5 35.1 33.3Brilliance ESBL 87.5 87.5 38.9 33.3BLSE 87.5 87.5 22.2 20.3

Grohs et al.,2013 (133)

2,337/354 Rectal swab (2,337) chromID ESBL 97.5 39.1Brilliance ESBL 98.6 29.5CHROMagar ESBL 98.3 38.7Drigalski � CAZ 97.2 32.5Drigalski � CTX 95.5 29.5

Blane et al.,2016 (134)

298/116 Stool (298) chromID ESBL 63 75Brilliance ESBL 59 68

aBLSE, A commercially available biplate comprising Drigalski agar (with 1.5 �g/ml cefotaxime) and MacConkey agar (with 2 �g/ml ceftazidime); MAC, MacConkey agar;CAZ, ceftazidime; CTX, cefotaxime; Drigalski � CAZ, BD Drigalski lactose agar with ceftazidime; Drigalski � CTX, Drigalski agar plus 2 �g/ml cefotaxime.




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

incubation in any of these studies (129, 131–134). The yield of ESBL producers may beincreased significantly (particularly on chromID ESBL) by extending incubation up to 48h (128, 134), and a preenrichment step may also significantly increase sensitivity (134).However, both of these strategies contribute to an even lower specificity (132, 134). Inthree of the studies in Table 5 the positive predictive value of chromogenic media wasreported to be significantly higher than that of nonchromogenic comparators (128, 130,132).

Carbapenemase-Producing Enterobacteriaceae

Perhaps the most significant development in clinical bacteriology over the lastdecade has been the global proliferation of Enterobacteriaceae with acquired carbap-enemase enzymes (carbapenemase-producing Enterobacteriaceae [CPE]) (135). Avail-able data suggest that the vast majority of carbapenemases in Enterobacteriaceaebelong to one of the five major families: the IMP, NDM, and VIM metalloenzymes andthe Klebsiella pneumoniae carbapenemase (KPC) and OXA-48-like enzymes (136). CPEare frequently resistant to virtually all �-lactam antibiotics (including carbapenems),and carbapenemase genes are transmissible via plasmids. Concomitant resistance toseveral other antimicrobial classes is common in CPE, dramatically reducing treatmentoptions for infected patients. CPE are frequently implicated in nosocomial outbreaks,and fecal carriage of CPE is an important reservoir for subsequent transmission (137). Inearly 2009, the Centers for Disease Control and Prevention (CDC) and the HealthcareInfection Control Practices Advisory Committee recommended measures for activesurveillance of Enterobacteriaceae with resistance to carbapenems in all acute-carefacilities in the United States (138). A practical screening method was also recom-mended by the CDC, which involved inoculation of rectal swabs into 5 ml of Trypticasesoy broth (TSB) along with a 10-�g ertapenem or meropenem disk (139). Afterincubation, the broth is subcultured to MacConkey agar, and lactose-fermenting col-onies are investigated for carbapenemase production or carbapenem resistance. De-tection of CPE is not straightforward, as not all carbapenemases confer clinical resis-tance to carbapenems and Enterobacteriaceae without carbapenemases may exhibitresistance to carbapenems via other mechanisms (140).

In 2008, Samra et al. evaluated CHROMagar KPC, the first chromogenic culturemedium for detection of CPE (9). The medium was an adaptation of CHROMagarOrientation with additional selective agents for inhibition of Gram-positive bacteria andcarbapenem-susceptible Gram-negative bacteria. CHROMagar KPC is also available asprepoured plates and is marketed as Colorex KPC (141). The authors compared cultureon CHROMagar KPC with culture on MacConkey agar (plus carbapenem disks) and aPCR method for detection of blaKPC genes. The sensitivity and specificity relative to PCRwere 100% and 98.4%, respectively, for CHROMagar KPC and 92.7% and 95.9%,respectively, for MacConkey agar with carbapenem disks. Since this first report, anumber of other chromogenic media have been made commercially available fordetection of CPE. As with media for the detection of ESBL producers, the principles ofthese media have much in common, and they allow for the differentiation of the mostrelevant Enterobacteriaceae (i.e., E. coli and the KES group) as well as incorporatingselective agents to inhibit Gram-positive bacteria and yeasts. The choice (and concen-tration) of antimicrobial(s) selected for inhibition of carbapenem-susceptible Entero-bacteriaceae is the most critical factor that influences sensitivity and specificity, and theinclusion of antimicrobials other than carbapenems may have advantages over theinclusion of a carbapenem (S. Ghirardi, J. D. Perry, and G. Zambardi, 4 October 2012,international patent application WO2012131217; L. Devigne, S. Ghirardi, and B. Zam-bardi, 30 January 2014, international patent application WO2014016534). However, theingredients of commercially available chromogenic media are typically undisclosed.

There have been a number of published studies that have examined the limit ofdetection of chromogenic agars for various types of CPE using challenge experimentswith pure cultures (142–151). While such studies are useful, they cannot replicate thechallenges that may be encountered when seeking to recover CPE from patient




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

samples. Consequently, the values for sensitivity and specificity reported in evaluationswith clinical samples are usually lower than those achieved with pure cultures (140).Table 6 summarizes the findings of the largest studies that have been performed withfecal samples (stool samples or rectal swabs) from patients (9, 152–159). In three earlystudies with CHROMagar KPC (9, 152, 153), sensitivity was equivalent to or higher thanthat of in-house preparations of MacConkey agar incorporating imipenem (or Mac-Conkey agar with carbapenem disks). Later studies revealed that isolates producingNDM-1 carbapenemase may be inhibited by CHROMagar/Colorex KPC if the isolateshave a relatively low MIC to meropenem (�2 �g/ml) (141, 143). This emphasizes theimportance of performing studies in different geographical areas where differentcarbapenemase enzymes may predominate. In a further example, chromID CARBA wasproven to be effective in comparative studies of media in Greece (154, 156) andPakistan (141, 160, 161) but had limited efficacy in Turkey (157) and Belgium (162),where OXA-48 is the dominant carbapenemase. To address this, the manufactureroffers a biplate (chromID CARBA SMART) that combines two media in a single petri dish:chromID CARBA and chromID OXA-48.

Brilliance CRE agar is marketed for the isolation of carbapenem-resistant Enterobac-teriaceae (CRE) rather than CPE. This medium was evaluated in two simultaneousstudies in two centers in Pakistan and showed a lower sensitivity and specificity than

TABLE 6 Summary of studies evaluating chromogenic media for the isolation of carbapenemase-producing Enterobacteriaceae frompatient samples


Total no. ofsamples/no. positive Test medium

Sensitivity(%)

Specificity(%)

Studylocation

Dominantenzyme(s)

Samra et al., 2008 (9)a 122/41 CHROMagar KPC 100 98.4 Israel KPCMacConkey agar � carbapenem disks 92.7 95.9

Adler et al., 2011 (152) 139/33 CHROMagar KPC 84.9 88.7 Israel KPCMacConkey agar � carbapenem disks 75.8 89.6MacConkey agar � imipenem (1 �g/ml) 84.9 94.3

Panagea et al., 2011(153)

126/46 CHROMagar KPC 97.8 Greece KPC, VIMMacConkey agar � imipenem (1 �g/ml) 78.3

Vrioni et al., 2012 (154) 200/73 TSBb � ertapenem (2 �g/ml) 89.1 86.4 Greece KPC, VIMchromID ESBL 92.4 93.3chromID ESBL (plus enrichment) 92.4 84.7chromID CARBA 92.4 96.9MacConkey agar � meropenem (1 �g/ml) 89.1 85.2

Vasoo et al., 2014 (155) 150/47 CHROMagar KPC 76.6 75.7 USA KPCRemel Spectra CRE 97.8 86.4MacConkey agar � ertapenem disks 83 73.8

Papadimitriou-Olivgeriset al., 2014 (156)

177/86 chromID CARBA 96.5 91.2 Greece KPCMacConkey agar � imipenem (1 �g/ml) 89.5 31.9TSB � ertapenem (2 �g/ml) 98.8 80.2

Zarakolu et al., 2015(157)

302/33 chromID CARBA 57.6 98.9 Turkey OXA-48chromID OXA-48 75.8 99.3TSB � ertapenem (2 �g/ml) 57.6 95.2

Davies et al., 2016(158)

236/33 Brilliance CRE 97 87.9 UK NDMchromID CARBA 97 91.5Colorex mSuperCarba 90.9 92.4MacConkey agar � carbapenem disks 69.7 91.8

Papadimitriou-Olivgeriset al., 2016 (159)

912/329 Brilliance CRE 96.8 90.9 Greece KPCCHROMagar KPC 99.2 78.2MacConkey agar � imipenem disk 67.2 98.1MacConkey agar � ertapenem disk 81.8 97.9

aThe sensitivity and specificity of both media were calculated relative to results obtained by PCR.bTSB, Trypticase soy broth.




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

chromID CARBA for detection of CPE with NDM-1 carbapenemase (160, 161). Theauthors speculated that the stability of Brilliance CRE may have been compromisedduring transport of the culture media from the UK to Pakistan. However, in challengeexperiments with pure cultures, a relatively low specificity of 71% was recorded for thismedium due to the growth of AmpC- and/or ESBL-producing isolates (146). In anotherstudy with Brilliance CRE with patient samples (n � 77), the specificity of Brilliance CREwas lower than that of SuperCarba (86.6% versus 98.5%, respectively) (149). However,the sensitivity of Brilliance CRE was significantly better than that of chromID CARBA fordetection of OXA-48 as shown by a study in Belgium (162). The sensitivity of bothmedia was improved by preenrichment of rectal swabs in MacConkey broth (althoughthis was not statistically significant), whereas prolonged incubation of media for 48 hshowed no advantage.

SuperCarba medium is a nonchromogenic medium for isolation of CPE that incor-porates a low concentration of ertapenem (0.5 �g/ml) in addition to cloxacillin in azinc-supplemented Drigalski-lactose agar (163). Studies with bacterial isolates suggesta high sensitivity for detection of all types of CPE, but stability of the medium is limitedto 1 week, and larger studies with patient samples are required. A chromogenicadaptation of this medium, CHROMagar mSuperCarba (also marketed as ColorexmSuperCarba) (Fig. 2d), has recently been made commercially available and shows acomparable sensitivity when tested with pure isolates of CPE (164). The medium, onceprepared, has an improved shelf life of 1 month. Davies et al. (158) recently reported anevaluation of Colorex mSuperCarba with rectal swabs and reported a sensitivity equiv-alent to that of chromID CARBA and Brilliance CRE for recovery of CPE that mostlyproduced NDM carbapenemase (Table 6). García-Fernández et al. cultured 211 rectalswabs from distinct patients onto CHROMagar mSuperCarba and compared its perfor-mance with culture on chromID CARBA, chromID OXA-48, and chromID ESBL (165). CPEwere detected in 61 samples (with OXA-48 reported as the dominant enzyme; n � 54),and the authors reported 100% sensitivity and specificity for CHROMagar mSuperCarba.The sensitivities of the comparator media were not reported.

In the three evaluations in Table 6 that included the CDC broth method, thesensitivity of chromogenic media was equivalent (154, 156) or better (157). Disadvan-tages of the CDC broth method include a longer time to detection (an extra day isrequired), lack of information regarding likely species identification, and the fact thatCPE may not be detected if they fail to ferment lactose on MacConkey agar. A furtherdisadvantage is that the CDC broth method is significantly more labor-intensive thanuse of a chromogenic medium, as shown by Mathers et al. (166).

It can be concluded that chromogenic media for CPE have clear advantages over theCDC broth method or the use of MacConkey agars supplemented with a carbapenemor used in conjunction with carbapenem disks. However, it is especially difficult toestablish which, if any, chromogenic medium is optimal for detection of CPE due to thedifferent types of carbapenemase that may be encountered and the dominance ofparticular types in certain geographical regions. In January 2016, Viau et al. publishedan extensive evaluation of all methods for the detection of CPE (140). Following adetailed statistical meta-analysis of published studies, the authors concluded thatchromID CARBA and the nonchromogenic SuperCarba medium have excellent sensi-tivities for class A �-lactamases (e.g., KPC) that rival that of real-time PCR and that theCDC broth method was generally inferior to chromogenic media. For other media, andother carbapenemase types, there was insufficient evidence to draw firm conclusions.

Carbapenem-Resistant Acinetobacter spp.

Species of Acinetobacter, and especially Acinetobacter baumannii, are importantnosocomial pathogens that have been responsible for outbreaks of infection amonghospitalized patients. Strains that are resistant to carbapenem antibiotics are particu-larly problematic, as infections caused by such strains can be very difficult to treat (167).In 2009 CHROMagar Acinetobacter, the first chromogenic medium for detection ofAcinetobacter spp., was described, and this medium can be used to detect all Acineto-




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

bacter spp. or it can be further supplemented to detect only isolates with resistance tocarbapenems (10). The chromogenic substrate used for detection of Acinetobacter spp.is undisclosed by the manufacturer. The authors evaluated the supplemented versionof CHROMagar Acinetobacter for detection of carbapenem-resistant strains from stoolsamples and perineal swabs of 70 patients and compared its performance to PCRfollowing enrichment culture. The sensitivity and specificity of the chromogenic me-dium compared with the PCR assay were reported as 91.7% and 89.6%, respectively(10).

There have been few subsequent published evaluations of CHROMagar Acinetobac-ter with clinical samples for the isolation of carbapenem-resistant isolates. Song et al.used an updated version of the medium (Fig. 1f) for isolation of carbapenem-resistantAcinetobacter from 406 paired nasal and rectal swabs (168). They confirmed the highspecificity of the medium for carbapenem-resistant Acinetobacter, but no comparator wasused for assessment of sensitivity. In a study using spiked stool samples, CHROMagarAcinetobacter had a reported sensitivity of 86.5% and a specificity of 75% for detection ofcarbapenemase-producing A. baumannii (169).

One question that deserves further attention is whether a single chromogenicmedium could be used by clinical laboratories to perform screening for bothcarbapenemase-producing Enterobacteriaceae and carbapenem-resistant Acinetobacter(170, 171). For example, Higgins et al. reported that a high proportion of carbapenem-resistant Acinetobacter strains with a diverse range of carbapenemase enzymes grow onchromID CARBA and that the medium effectively inhibits the growth of carbapenem-susceptible isolates (170). Zarakolu et al. evaluated CHROMagar Acinetobacter and chromIDCARBA for the isolation of carbapenem-resistant Acinetobacter with 203 stool samples frompatients at a hospital in Turkey (171). There was no significant difference between the twomedia, with sensitivities of 66% and 77%, respectively (P � 0.48) and comparable values forpositive predictive value (62% and 68%). However, all isolates belonged to a single species(A. baumannii), and all produced OXA-23 carbapenemase. Further studies are thereforewarranted for evaluation of CHROMagar Acinetobacter in different geographical areas, andit would be useful if further studies can establish whether separate media are necessary forscreening for CPE and carbapenem-resistant Acinetobacter.

IMPACT OF LABORATORY AUTOMATION ON THE USE OF CHROMOGENIC MEDIA

Another major development of the last decade has been the introduction ofMALDI-TOF MS into many clinical laboratories for rapid and accurate identificationof species (172). In many ways this has proven to be a powerful adjunct to the use ofchromogenic media (and culture methods in general), as culture is a prerequisite for themajority of MALDI-TOF MS applications in diagnostic microbiology. None of the chro-mogenic media described in this review allows for absolute specificity in terms ofpathogen detection, and colonies therefore require further identification. The mainbenefits of MALDI-TOF MS have been to reduce the time required to less than an hourfor confirmation of pathogens isolated by culture and to reduce the cost of identifica-tion. Also, as multiple colonies can be quickly screened to provide species-levelidentification, the availability of MALDI-TOF MS can compensate, to some extent, for alack of specificity of some culture media. This may tempt some to choose less expensiveconventional media rather than chromogenic media, but the availability of MALDI-TOFMS cannot compensate for any deficit in sensitivity; i.e., it can be applied only tocolonies that have actually been detected in the first place. As well as providing speciesidentification, the confirmation of ESBL or carbapenemase enzymes using MALDI-TOFMS is also possible (173, 174). A number of studies have confirmed the value andcompatibility of MALDI-TOF MS when used in conjunction with many of the chromo-genic media described in this review (see, e.g., references 46, 74, 158, and 175).Innovative applications of other forms of mass spectrometry that demonstrate thefeasibility of detecting a broad variety of resistance enzymes directly from limitedbiomaterials have also been published (176).

Other developments in laboratory automation also strengthen the continued role of




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

culture media, and chromogenic media in particular, in the clinical laboratory. Theseinclude automated methods for inoculation of culture plates (177) and methods forautomated digital analysis that enable detection and enumeration of colored colonies(178, 179). Digital imaging software is capable of distinguishing differences in pixelcolor, and chromogenic media are particularly suited to digital automation, as colorthresholds can be created to detect target growth of specific pathogens (179). Faron etal. exploited this technology to screen for MRSA in a multicenter study using theWASPLab chromogenic detection module (179). Three different chromogenic media,MRSASelect, CHROMagar MRSA, and chromID MRSA, were used, and cultures from57,690 screening swabs were interpreted by manual reading of digital images and byautomated digital analysis. Automated analysis demonstrated 100% sensitivity for allthree chromogenic media and 90.7% specificity, indicating that automated analysis washighly reliable for reporting negative samples (which constituted 88.6% of total sam-ples in this study). Technologist support was required for examination of culturesdeclared “positive” by automated analysis to rule out false positives. A total of 5,057false-positive results were reported by the automated digital analysis (8.8% of totalsamples). Of interest, automated digital analysis detected colored colonies in 153positive cultures that were “missed” by the first manual reading but declared positivewhen discrepant results were reviewed manually (179).

Faron et al. reported on the use of the same technology for detection of VRE in104,730 rectal swabs cultured onto Colorex VRE and Oxoid VRE (178). The sensitivityand specificity of automated digital analysis were 100% and 89.5% compared withmanual interpretation of digital images, and the automated method correctly identifiedall negative cultures, which comprised 84% (87,973) of the specimens in this study.There were discordant results for 10,348 specimens, and these were reexaminedmanually. This reexamination revealed 499 positive cultures that were missed by thefirst manual reading. Most of the other discordant results were falsely identified aspositive by the automated system and were attributed to residual specimen matrix,yeast growth, or colonies with borderline color development (178). The authors calcu-lated that the application of automated specimen processing and reading of culturesallowed a saving of approximately $5 per negative sample due to the reduction in labortime. The issue of automatic digital plate reading for surveillance cultures is the subjectof a recent commentary (180).

CULTURE USING CHROMOGENIC MEDIA VERSUS MOLECULAR DIAGNOSTICMETHODS

A wide range of molecular diagnostic assays, including PCR, microarrays, andwhole-genome sequencing, is becoming available to diagnostic clinical laboratories.Clinical microbiologists are increasingly required to assess the relative merits andclinical impact of such methods against those of culture, using either conventional orchromogenic media. The primary consideration in such decision-making is the relativesensitivities of competing tests, and a number of investigators have sought to elucidatethe relative sensitivity of molecular methods versus culture using chromogenic mediafor direct testing of clinical samples. Evidence suggests that PCR and culture usingchromogenic media have equivalent sensitivity when used as screening tests for C.difficile (181, 182) and vancomycin-resistant enterococci (183–186). However, culture forC. difficile requires subsequent confirmation of toxin genes, whereas PCR has theadvantage of specifically detecting toxigenic C. difficile. For detection of S. agalactiae,there is evidence that PCR methods are more sensitive than direct culture on chromo-genic media (38, 187); however, there is no significant difference when PCR is comparedwith culture on chromogenic media after broth enrichment (38, 188–190).

Infectious causes of gastroenteritis (GI) may include several bacterial pathogens anda range of viruses and parasites. Laboratory diagnosis by conventional methods istherefore cumbersome and requires a combination of methods that commonly in-cludes culture (including enrichment broth[s]), microscopy, and immunoassays. Forsome GI pathogens, e.g., STEC, there is a clear advantage of molecular assays compared




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

to any form of culture, as discussed above. De Boer et al. employed a multiplex PCRassay to target four bacterial gastrointestinal pathogens (Salmonella spp. Campylobac-ter jejuni, STEC, and Shigella/enteroinvasive E. coli) in 13,974 stool samples. Theyreported that the molecular assay markedly improved rates of detection of all patho-gens apart from Salmonella spp. compared to culture on conventional media (191). Theuse of commercial platforms that employ multiplexed molecular assays and canaccommodate a large number of targets is an increasingly attractive option to simplifylaboratory workflow. One example of such a platform is the FilmArray GI panel, whichconsists of automated nucleic acid extraction, reverse transcription, amplification, andanalysis and can detect 22 pathogens, with results available within 1 h. In a multicenterstudy, Buss et al. examined the performance of this panel for detection of a range of GIpathogens in 1,556 stool samples (192). Using conventional culture (with nonchromo-genic media) as a comparator, the molecular assay showed high sensitivity (94.5 to100%) for detection of Salmonella, Yersinia, STEC, Campylobacter, C. difficile, and Shi-gella, as well as other pathogens. There was also evidence that certain pathogens (e.g.,Campylobacter upsaliensis and Plesiomonas shigelloides) were poorly detected by cul-ture (192). In conclusion, there is good evidence that molecular platforms offer highsensitivity and versatility for the convenient detection of a range of GI pathogens (193),and there is evidence of accelerated uptake of these tests, particularly in the UnitedStates (194). Although most comparative studies have not included chromogenicmedia, any advantage of chromogenic media over conventional media for detection ofGI pathogens is unlikely to be a major consideration in deciding whether to use cultureor a molecular platform.

A considerable amount of work has focused on the potential advantages of PCR forthe rapid detection of patients colonized with MRSA. In 2011, Luteijn et al. publisheda systematic review and meta-analysis of 29 studies that compared PCR with culture onchromogenic media for detection of MRSA in screening swabs (105). There was nosignificant difference between the two methods if results of chromogenic culture wereconsidered after incubation for 48 h. Subsequent studies have shown conflictingresults, with chromogenic media found to be equivalent (195–197), inferior (198), orsuperior (199–201) to a variety of PCR methods. The obvious potential advantage ofPCR over culture is the significantly reduced turnaround time required for detection ofMRSA. For example, Roisin et al. reported that use of PCR led to a reduction in themedian turnaround time from admission to notification of positive results from 88 h to11 h and reduced the median time between admission and isolation of newly detectedMRSA carriers from 96 h to 25 h (202). Despite this, a reduction in nosocomialtransmission of MRSA was not demonstrated. Reductions in turnaround time and thenumber of days required for patient isolation were also confirmed by a systematicreview by Polisena et al. (203). In a major study, Derde et al. examined the impact ofscreening using PCR versus screening using chromogenic media to examine theacquisition and transmission of MRSA (and other resistant bacteria) on 13 intensive careunits in eight countries. The authors could not find any positive impact of PCR onacquisition rates (204).

The accumulated evidence suggests that chromogenic media have a sensitivity thatis comparable to that of PCR for detection of MRSA if cultures are incubated for 48 hor enrichment culture is included. PCR offers the advantage of a significantly fasterturnaround time and may facilitate prompt isolation of colonized patients and/or areduced number of days of isolation. Despite this, there is no evidence of a reduced rateof MRSA acquisition. The ongoing debate surrounding the need for, and extent of,screening of patients for MRSA is beyond the scope of this review (97).

There are a very limited number of studies that have compared PCR with culture onchromogenic media for detection of CPE directly from clinical samples. As notedpreviously, it is likely that the two methods have comparable sensitivity for detectionof strains harboring KPC carbapenemase (9, 140). However, there is at least circum-stantial evidence that isolates with other carbapenemases (and perhaps lower levels ofresistance to carbapenems) may be more readily detected by molecular methods such




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

as PCR. In a study in Belgium, Huang et al. applied the Check-Direct CPE PCR assay forthe testing of 394 rectal swabs to detect CPE carriage and also cultured the swabs ontwo chromogenic media (chromID CARBA/chromID OXA-48) (205). They reported thatCPE was detected by PCR in 38 samples but that only 17 samples yielded CPE byculture. OXA-48 was the dominant carbapenemase enzyme. Of the 21 samples thatwere positive by PCR but negative on culture, five of the samples were from patientswith previous carriage of CPE, and a further six samples (all with OXA-48 detected byPCR) were from patients located in a center where a longstanding outbreak of OXA-48-producing Klebsiella pneumoniae was occurring. It is possible that this study dem-onstrates a superior sensitivity of PCR for detection of CPE, although the possibility thatcarbapenemase genes were detected in species other than Enterobacteriaceae that maynot be targeted by chromogenic media cannot be excluded (206, 207). Otter et al.performed screening of 4,006 patients for CPE using PCR (Check-Direct CPE assay) andculture on a chromogenic medium (chromID CARBA SMART) at a hospital in London, UK(208). Culture was also performed on all samples using a conventional agar (MacConkeyagar plus a 10-�g ertapenem disk), and samples that were positive using PCR butnegative by culture were screened for CPE using two different enrichment broths. Usingculture, only six CPE were recovered from five patients (0.1%). Five CPE were detectedusing the chromogenic medium, compared with only one using the conventional agar,whereas the PCR assay failed to detect two CPE with OXA-48 carbapenemase. Samplesfrom 76 patients were culture negative but were positive using the Check-Direct CPEassay. No CPE could be recovered from these 76 samples using two types of enrichmentculture, and only 2/76 samples generated a positive PCR test when the same sampleswere retested 1 to 2 months later. After assessing evidence from this and other studies,the authors recommended that a lower threshold cycle (CT) cutoff value of �35 shouldbe introduced in order to reduce the number of false-positive PCR results. They alsoconcluded that screening using PCR may not be cost-effective in a setting with such alow prevalence (208). There is a pressing need for further trials of PCR versus culture onchromogenic media for detection of CPE.

For other chromogenic applications covered by this review, the lack of publishedcomparisons with molecular methods using clinical samples precludes any meaningfulanalysis.

Other than assessing the test performance, the choice of whether to use a chro-mogenic culture method or a molecular method will be determined by additionalfactors, which most notably include the cost per test (and the cost of associatedinstrumentation) and the likely impact of turnaround time on patient management.PCR tests are generally significantly more expensive than cultures using chromogenicmedia, but PCR results are normally available within a few hours, whereas cultureresults will be available only after 18 to 48 h. In reality, this is no longer a binary choice,and an increasing trend in clinical microbiology over the last decade has been the needto develop diagnostic algorithms that combine two or more complementary tests. Thisis well recognized in the diagnosis of C. difficile infection, where a diagnostic algorithmmight conceivably include an enzyme immunoassay(s), chromogenic culture, MALDI-TOF MS, and PCR for toxin genes (209, 210). Following culture of presumptive coloniesof CPE (or VRE) on chromogenic media, a PCR test is desirable for confirmation of thepresence of a resistance gene and identification of the type of gene allele present.Conversely, if resistance genes are detected in a rectal swab using PCR, culture is thennecessary in order to identify the species harboring the gene and to perform subse-quent analyses (e.g., antimicrobial susceptibility testing).

Despite the increasing use of culture-independent tests for detection of GI patho-gens, culture remains important for isolation of bacterial pathogens that have beendetected by such methods. This enables susceptibility tests to be performed and isessential for monitoring outbreaks of infection and, where possible, linking suchoutbreaks to their primary source, e.g., contaminated food. This issue has come intosharper focus in the last year, with the CDC characterizing culture-independent tests as“a serious and current threat to public health surveillance, particularly for STEC and




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

Salmonella” (194). In the long term, metagenomic approaches may allow referencelaboratories to type enteropathogens directly from clinical samples, but until such testsare widely available, it is essential that culture methods are utilized for recovery ofpathogens to allow for typing of isolates and investigation of outbreaks. For suchculture methods, the relative attributes of chromogenic versus conventional agarsshould be carefully considered.

CONCLUSIONS

The last decade has seen a rapid expansion in the range of chromogenic culturemedia available to clinical laboratories. In most cases, a clear advantage over conven-tional culture media can be demonstrated. This not only is due to the inclusion ofchromogenic substrates that allow detection of pathogens with high specificity butalso is due to the inclusion of optimal combinations of selective agents that preventinterference from nontarget microorganisms. In some cases, media that have beendesigned primarily for the isolation of pathogens (e.g., Campylobacter spp., Y. entero-colitica, and Vibrio spp.) from food have found application in clinical diagnostics. Thistrend continues with a recent report of Listeria chromogenic agar applied to thediagnosis of neonatal bacteremia (211). New culture media continue to be developedas research tools, as well as for routine diagnostics, such as the recent report of achromogenic medium for isolation of antimicrobial-resistant strains of Bacteroidesfragilis (212). It is also likely that bacteria with new forms of antimicrobial resistancewill be targeted by new chromogenic media. This is exemplified by the adaptationof CHROMagar Orientation for the detection of Enterobacteriaceae with acquiredresistance to colistin (213). Where MALDI-TOF MS is available, the potential attri-butes of chromogenic media should now be assessed in this context, as MALDI-TOFMS may compensate for any lack of specificity and contribute to an even shortertime to result.

When looking to the future, it is tempting to anticipate the systematic replacementof culture methods with PCR-based methods to overcome the inherent delay associ-ated with culture. However, there are also inherent drawbacks in the exclusive use ofmolecular methods. For example, isolation of bacterial pathogens remains essential inorder to perform antimicrobial susceptibility testing, which means that effective culturemethods must still be available for investigation of samples that are positive using PCR.In the long term, this issue may be resolved by whole-genome sequencing of speciesdirectly from clinical samples. However, for most bacterial species there is currentlyinsufficient evidence to support the use of whole-genome sequencing to infer antimi-crobial susceptibility even when a pure culture is available (214). Another inherentdisadvantage of PCR methods is that new genes or gene variants that may compromiseassay performance continuously appear. For example, a pathogen that harbors a newgene conferring antimicrobial resistance may evade detection by PCR but is likely to berecovered on chromogenic media due to phenotypic expression of resistance (200). Forsome applications, the convenience offered by molecular methods is compelling, forexample, the ability to screen simultaneously and effectively for a wide variety ofenteric pathogens. For some other applications, the evidence suggests that chromo-genic media are at least as convenient and sensitive as well as being more cost-effective. As clinical bacteriology grows in complexity, not least due to the widespreademergence of bacteria with resistance to multiple antimicrobials, chromogenic mediashould no longer be assessed as individual tools but as potentially useful componentswithin diagnostic algorithms.

ACKNOWLEDGMENTSThe Freeman Hospital Microbiology Department has received funding from bio-

Mérieux for the development and evaluation of culture media, and I have performedconsultancy work for the same company. The Freeman Hospital Microbiology Depart-ment has also received funding for evaluation studies from Bio-Rad Laboratories andInternational Diagnostics Group.




http://cmr.asm

.org/D

ownloaded from

http://cmr.asm.org

http://cmr.asm.org/

REFERENCES1. Dusch H, Altwegg M. 1993. Comparison of Rambach agar, SM-ID me-

dium, and Hektoen Enteric agar for primary isolation of non-typhisalmonellae from stool samples. J Clin Microbiol 31:410 – 412.

2. Odds FC, Bernaerts R. 1994. CHROMagar Candida, a new differentialisolation medium for presumptive identification of clinically importantCandida species. J Clin Microbiol 32:1923–1929.

3. Mazoyer MA, Orenga S, Doleans F, Freney J. 1995. Evaluation of CPS ID2medium for detection of urinary tract bacterial isolates in specimensfrom a rehabilitation center. J Clin Microbiol 33:1025–1027.

4. Gaillot O, Wetsch M, Fortineau N, Berche P. 2000. Evaluation of CHRO-Magar Staph. aureus, a new chromogenic medium, for isolation andpresumptive identification of Staphylococcus aureus from human clin-ical specimens. J Clin Microbiol 38:1587–1591.

5. Merlino J, Leroi M, Bradbury R, Veal D, Harbour C. 2000. New chromo-genic identification and detection of Staphylococcus aureus andmethicillin-resistant S. aureus. J Clin Microbiol 38:2378 –2380.

6. Perry JD, Oliver M, Nicholson A, Wright J, Gould FK. 2006. Evaluation ofa new chromogenic agar medium for isolation and identification ofgroup B streptococci. Lett Appl Microbiol 43:615– 618. https://doi.org/10.1111/j.1472-765X.2006.02023.x.

7. Glupczynski Y, Berhin C, Bauraing C, Bogaerts P. 2007. Evaluation of anew selective chromogenic agar medium for detection of extended-spectrum beta-lactamase-producing Enterobacteriaceae. J Clin Micro-biol 45:501–505. https://doi.org/10.1128/JCM.02221-06.

8. Ledeboer NA, Das K, Eveland M, Roger-Dalbert C, Mailler S, Chatellier S,Dunne WM. 2007. Evaluation of a novel chromogenic agar medium forisolation and differentiation of vancomycin-resistant Enterococcus fae-cium and Enterococcus faecalis isolates. J Clin Microbiol 45:1556 –1560.https://doi.org/10.1128/JCM.02116-06.

9. Samra Z, Bahar J, Madar-Shapiro L, Aziz N, Israel S, Bishara J. 2008.Evaluation of CHROMagar KPC for rapid detection of carbapenem-resistant Enterobacteriaceae. J Clin Microbiol 46:3110 –3111. https://doi.org/10.1128/JCM.00249-08.

10. Gordon NC, Wareham DW. 2009. Evaluation of CHROMagar Acineto-bacter for detection of enteric carriage of multidrug-resistant Acineto-bacter baumannii in samples from critically ill patients. J Clin Microbiol47:2249 –2251. https://doi.org/10.1128/JCM.00634-09.

11. Laine L, Perry JD, Lee J, Oliver M, James AL, De La Foata C, Halimi D,Orenga S, Galloway A, Gould FK. 2009. A novel chromogenic mediumfor isolation of Pseudomonas aeruginosa from the sputa of cystic fibro-sis patients. J Cyst Fibros 8:143–149. https://doi.org/10.1016/j.jcf.2008.11.003.

12. Grys TE, Sloan LM, Rosenblatt JE, Patel R. 2009. Rapid and sensitivedetection of Shiga toxin-producing Escherichia coli from nonenrichedstool specimens by real-time PCR in comparison to enzyme immuno-assay and culture. J Clin Microbiol 47:2008 –2012. https://doi.org/10.1128/JCM.02013-08.

13. Perry JD, Asir K, Halimi D, Orenga S, Dale J, Payne M, Carlton R, EvansJ, Gould FK. 2010. Evaluation of a chromogenic culture medium forisolation of Clostridium difficile within 24 hours. J Clin Microbiol 48:3852–3858. https://doi.org/10.1128/JCM.01288-10.

14. Le Bars H, Kayal S, Bonnaure-Mallet M, Minet J. 2011. CASA chromo-genic medium for enteric Campylobacter species. J Clin Microbiol 49:3675–3677. https://doi.org/10.1128/JCM.00899-11.

15. Canizalez-Roman A, Flores-Villaseñor H, Zazueta-Beltran J, Muro-Amador S, León-Sicairos N. 2011. Comparative evaluation of a chromo-genic agar medium-PCR protocol with a conventional method forisolation of Vibrio parahaemolyticus strains from environmental andclinical samples. Can J Microbiol 57:136 –142. https://doi.org/10.1139/W10-108.

16. Hinde G, Ul-Hasan M, Brensan J, Berger D. 2012. Evaluation of a novelchromogenic medium as a replacement for MacConkey agar and Hek-toen Enteric agar. Abstr 112th Gen Meet Am Soc Microbiol, 16 to 19June 2012, San Francisco, CA. http://hardydiagnostics.com/pdf/sc_posters/hardychrom-macconkey-hektoen-enteric.pdf.

17. Renaud N, Lecci L, Courcol RJ, Simonet M, Gaillot O. 2013. CHROMagarYersinia, a new chromogenic agar for screening of potentially patho-genic Yersinia enterocolitica isolates in stools. J Clin Microbiol 51:1184 –1187. https://doi.org/10.1128/JCM.02903-12.

18. Orenga S, James AL, Manafi M, Perry JD, Pincus DH. 2009. Enzymatic

substrates in microbiology. J Microbiol Methods 79:139 –155. https://doi.org/10.1016/j.mimet.2009.08.001.

19. Freydière AM, Buchaille L, Gille Y. 1997. Comparison of three commer-cial media for direct identification and discrimination of Candida spe-cies in clinical specimens. Eur J Clin Microbiol Infect Dis 16:464 – 467.https://doi.org/10.1007/BF02471913.

20. Willinger B, Hillowoth C, Selitsch B, Manafi M. 2001. Performance ofCandida ID, a new chromogenic medium for presumptive identificationof Candida species, in comparison to CHROMagar Candida. J ClinMicrobiol 39:3793–3795. https://doi.org/10.1128/JCM.39.10.3793-3795.2001.

21. Cooke VM, Miles RJ, Price RG, Midgley G, Khamri W, Richardson AC.2002. New chromogenic agar medium for the identification of Candidaspp. Appl Environ Microbiol 68:3622–3627. https://doi.org/10.1128/AEM.68.7.3622-3627.2002.

22. Shibata A, Kaneko T, Makimura K, Onozaki M, Ogihara T, Shibata H,Kikuchi K, Abe S. 2008. Comparative study of ability for growth supportand species differentiation by colony features on commercial chromo-genic agar, Pourmedia Vi Candida and CHROMagar Candida. NihonIshinkin Gakkai Zasshi 49:33–38. https://doi.org/10.3314/jjmm.49.33.

23. Ozcan K, Ilkit M, Ates A, Turac-Bicer A, Demirhindi H. 2010. Perfor-mance of Chromogenic Candida agar and CHROMagar Candida inrecovery and presumptive identification of monofungal and poly-fungal vaginal isolates. Med Mycol 48:29 –34. https://doi.org/10.3109/13693780802713224.

24. Alfonso C, López M, Arechavala A, Perrone MDC, Guelfand L, Bianchi M;Red de Micología del Gobierno de la Ciudad Autónoma de BuenosAires. 2010. Presumptive identification of Candida spp. and other clin-ically important yeasts: usefulness of Brilliance Candida agar. Rev Ibe-roam Micol 27:90 –93. https://doi.org/10.1016/j.riam.2010.01.008.

25. Daef E, Moharram A, Eldin SS, Elsherbiny N, Mohammed M. 2014.Evaluation of chromogenic media and seminested PCR in the identifi-cation of Candida species. Braz J Microbiol 45:255–262. https://doi.org/10.1590/S1517-83822014005000040.

26. Murray CK, Beckius ML, Green JA, Hospenthal DR. 2005. Use of chro-mogenic medium in the isolation of yeasts from clinical specimens. JMed Microbiol 54:981–985. https://doi.org/10.1099/jmm.0.45942-0.

27. Hospenthal DR, Beckius ML, Floyd KL, Horvath LL, Murray CK. 2006.Presumptive identification of Candida species other than C. albicans, C.krusei, and C. tropicalis with the chromogenic medium CHROMagarCandida. Ann Clin Microbiol Antimicrob 5:1. https://doi.org/10.1186/1476-0711-5-1.

28. Sendid B, François N, Standaert A, Dehecq E, Zerimech F, Camus D,Poulain D. 2007. Prospective evaluation of the new chromogenic me-dium CandiSelect 4 for differentiation and presumptive identification ofthe major pathogenic Candida species. J Med Microbiol 56:495– 499.https://doi.org/10.1099/jmm.0.46715-0.

29. Zaytsev AV, Anderson RJ, Bedernjak A, Groundwater PW, Huang Y,Perry JD, Orenga S, Roger-Dalbert C, James A. 2008. Synthesis andtesting of chromogenic phenoxazinone substrates for beta-alanyl ami-nopeptidase. Org Biomol Chem 6:682– 692. https://doi.org/10.1039/b716978g.

30. Weiser R, Donoghue D, Weightman A, Mahenthiralingam E. 2014.Evaluation of five selective media for the detection of Pseudomonasaeruginosa using a strain panel from clinical, environmental and indus-trial sources. J Microbiol Methods 99:8 –14. https://doi.org/10.1016/j.mimet.2014.01.010.

31. Perry JD, Rennison C, Butterworth LA, Hopley AL, Gould FK. 2003.Evaluation of S. aureus ID, a new chromogenic agar medium fordetection of Staphylococcus aureus. J Clin Microbiol 41:5695–5698.https://doi.org/10.1128/JCM.41.12.5695-5698.2003.

32. Hirvonen JJ, Kerttula AM, Kaukoranta SS. 2014. Performance of SaSelect,a chromogenic medium for detection of staphylococci in clinical spec-imens. J Clin Microbiol 52:1041–1044. https://doi.org/10.1128/JCM.03129-13.

33. Carricajo A, Treny A, Fonsale N, Bes M, Reverdy ME, Gille Y, Aubert G,Freydière AM. 2001. Performance of the chromogenic medium CHRO-Magar Staph aureus and the Staphychrom coagulase test in the de-tection and identification of Staphylococcus aureus in clinical speci-mens. J Clin Microbiol 39:2581–2583. https://doi.org/10.1128/JCM.39.7.2581-2583.2001.




http://cmr.asm

.org/D

ownloaded from

https://doi.org/10.1111/j.1472-765X.2006.02023.x

https://doi.org/10.1111/j.1472-765X.2006.02023.x

https://doi.org/10.1128/JCM.02221-06

https://doi.org/10.1128/JCM.02116-06

https://doi.org/10.1128/JCM.00249-08

https://doi.org/10.1128/JCM.00249-08

https://doi.org/10.1128/JCM.00634-09

https://doi.org/10.1016/j.jcf.2008.11.003

https://doi.org/10.1016/j.jcf.2008.11.003

https://doi.org/10.1128/JCM.02013-08

https://doi.org/10.1128/JCM.02013-08

https://doi.org/10.1128/JCM.01288-10

https://doi.org/10.1128/JCM.00899-11

https://doi.org/10.1139/W10-108

https://doi.org/10.1139/W10-108

http://hardydiagnostics.com/pdf/sc_posters/hardychrom-macconkey-hektoen-enteric.pdf

http://hardydiagnostics.com/pdf/sc_posters/hardychrom-macconkey-hektoen-enteric.pdf

https://doi.org/10.1128/JCM.02903-12

https://doi.org/10.1016/j.mimet.2009.08.001


https://doi.org/10.1007/BF02471913

https://doi.org/10.1128/JCM.39.10.3793-3795.2001

https://doi.org/10.1128/JCM.39.10.3793-3795.2001

https://doi.org/10.1128/AEM.68.7.3622-3627.2002

https://doi.org/10.1128/AEM.68.7.3622-3627.2002

https://doi.org/10.3314/jjmm.49.33

https://doi.org/10.3109/13693780802713224

https://doi.org/10.3109/13693780802713224

https://doi.org/10.1016/j.riam.2010.01.008

https://doi.org/10.1590/S1517-83822014005000040

https://doi.org/10.1590/S1517-83822014005000040

https://doi.org/10.1099/jmm.0.45942-0

https://doi.org/10.1186/1476-0711-5-1

https://doi.org/10.1186/1476-0711-5-1

https://doi.org/10.1099/jmm.0.46715-0

https://doi.org/10.1039/b716978g

https://doi.org/10.1039/b716978g



https://doi.org/10.1128/JCM.41.12.5695-5698.2003

https://doi.org/10.1128/JCM.03129-13

https://doi.org/10.1128/JCM.03129-13

https://doi.org/10.1128/JCM.39.7.2581-2583.2001

https://doi.org/10.1128/JCM.39.7.2581-2583.2001

http://cmr.asm.org

http://cmr.asm.org/

34. Flayhart D, Lema C, Borek A, Carroll KC. 2004. Comparison of the BBLCHROMagar Staph aureus agar medium to conventional media fordetection of Staphylococcus aureus in respiratory samples. J Clin Micro-biol 42:3566 –3569. https://doi.org/10.1128/JCM.42.8.3566-3569.2004.

35. Centers for Disease Control and Prevention. 2007. Perinatal group Bstreptococcal disease after universal screening recommendations—United States, 2003-2005. MMWR Morb Mortal Wkly Rep 56:701–705.

36. De La Rosa M, Villareal R, Vega D, Miranda C, Martinezbrocal A. 1983.Granada medium for detection and identification of group B strepto-cocci. J Clin Microbiol 18:779 –785.

37. Morita T, Feng D, Kamio Y, Kanno I, Somaya T, Imai K, Inoue M, FujiwaraM, Miyauchi A. 2014. Evaluation of chromID strepto B as a screeningmedia for Streptococcus agalactiae. BMC Infect Dis 14:46. https://doi.org/10.1186/1471-2334-14-46.

38. Smith D, Perry JD, Laine L, Galloway A, Gould FK. 2008. Comparison ofBD GeneOhm real-time polymerase chain reaction with chromogenicand conventional culture methods for detection of group B Streptococ-cus in clinical samples. Diagn Microbiol Infect Dis 61:369 –372. https://doi.org/10.1016/j.diagmicrobio.2008.03.007.

39. Craven RR, Weber CJ, Jennemann RA, Dunne WM, Jr. 2010. Evaluationof a chromogenic agar for detection of group B Streptococcus inpregnant women. J Clin Microbiol 48:3370 –3371. https://doi.org/10.1128/JCM.00221-10.

40. El Aila NA, Tency I, Claeys G, Saerens B, Cools P, Verstraelen H, Tem-merman M, Verhelst R, Vaneechoutte M. 2010. Comparison of differentsampling techniques and of different culture methods for detection ofgroup B Streptococcus carriage in pregnant women. BMC Infect Dis10:285. https://doi.org/10.1186/1471-2334-10-285.

41. Louie L, Kotowich L, Meaney H, Vearncombe M, Simor AE. 2010.Evaluation of a new chromogenic medium (StrepB select) for detectionof group B Streptococcus from vaginal-rectal specimens. J Clin Microbiol48:4602– 4603. https://doi.org/10.1128/JCM.01168-10.

42. Poisson DM, Evrard ML, Freneaux C, Vivès MI, Mesnard L. 2011. Evalu-ation of CHROMagar™ StrepB agar, an aerobic chromogenic mediumfor prepartum vaginal/rectal group B Streptococcus screening. J Micro-biol Methods 84:490 – 491. https://doi.org/10.1016/j.mimet.2011.01.014.

43. Kwatra G, Madhi SA, Cutland CL, Buchmann EJ, Adrian PV. 2013.Evaluation of Trans-Vag broth, colistin-nalidixic agar, and CHROMagarStrepB for detection of group B Streptococcus in vaginal and rectalswabs from pregnant women in South Africa. J Clin Microbiol 51:2515–2519. https://doi.org/10.1128/JCM.00251-13.

44. Ghaddar N, Alfouzan W, Anastasiadis E, Al Jiser T, Itani SE, Dernaika R,Charafeddine A, Dhar R, El Hajj H. 2014. Evaluation of chromogenicmedium and direct latex agglutination test for detection of group BStreptococcus in vaginal specimens from pregnant women in Lebanonand Kuwait. J Med Microbiol 63:1395–1399. https://doi.org/10.1099/jmm.0.066738-0.

45. Tazi A, Réglier-Poupet H, Dautezac F, Raymond J, Poyart C. 2008.Comparative evaluation of Strepto B ID chromogenic medium andGranada media for the detection of group B Streptococcus from vaginalsamples of pregnant women. J Microbiol Methods 73:263–265. https://doi.org/10.1016/j.mimet.2008.02.024.

46. Joubrel C, Gendron N, Dmytruk N, Touak G, Verlaguet M, Poyart C,Réglier-Poupet H. 2014. Comparative evaluation of 5 different selectivemedia for group B Streptococcus screening in pregnant women. DiagnMicrobiol Infect Dis 80:282–284. https://doi.org/10.1016/j.diagmicrobio.2014.08.005.

47. Poisson DM, Chandemerle M, Guinard J, Evrard ML, Naydenova D,Mesnard L. 2010. Evaluation of CHROMagar StrepB: a new chromogenicagar medium for aerobic detection of group B streptococci in perinatalsamples. J Microbiol Methods 82:238 –242. https://doi.org/10.1016/j.mimet.2010.06.008.

48. Verhoeven PO, Noyel P, Bonneau J, Carricajo A, Fonsale N, Ros A,Pozzetto B, Grattard F. 2014. Evaluation of the new Brilliance GBSchromogenic medium for screening of Streptococcus agalactiae vaginalcolonization in pregnant women. J Clin Microbiol 52:991–993. https://doi.org/10.1128/JCM.02926-13.

49. Salem N, Anderson JJ. 2015. Evaluation of four chromogenic media forthe isolation of group B Streptococcus from vaginal specimens inpregnant women. Pathology 47:580 –582. https://doi.org/10.1097/PAT.0000000000000299.

50. Perry JD, Freydière AM. 2007. The application of chromogenic media in

clinical microbiology. J Appl Microbiol 103:2046 –2055. https://doi.org/10.1111/j.1365-2672.2007.03442.x.

51. Hengstler KA, Hammann R, Fahr AM. 1997. Evaluation of BBL CHRO-Magar Orientation medium for detection and presumptive identifica-tion of urinary tract pathogens. J Clin Microbiol 35:2773–2777.

52. Carricajo A, Boiste S, Thore J, Aubert G, Gille Y, Freydière AM. 1999.Comparative evaluation of five chromogenic media for detection,enumeration and identification of urinary tract pathogens. Eur JClin Microbiol Infect Dis 18:796 – 803. https://doi.org/10.1007/s100960050403.

53. Chaux C, Crepy M, Xueref S, Roure C, Gille Y, Freydière AM. 2002.Comparison of three chromogenic agar plates for isolation and iden-tification of urinary tract pathogens. Clin Microbiol Infect 8:641– 645.https://doi.org/10.1046/j.1469-0691.2002.00433.x.

54. Fallon D, Ackland G, Andrews N, Frodsham D, Howe S, Howells K, NyeKJ, Warren RE. 2003. A comparison of the performance of commerciallyavailable chromogenic agars for the isolation and presumptive identi-fication of organisms from urine. J Clin Pathol 56:608 – 612. https://doi.org/10.1136/jcp.56.8.608.

55. Lakshmi V, Satheeshkumar T, Kulkarni G. 2004. Utility of Urichrom II—achromogenic medium for uropathogens. Indian J Med Microbiol 22:153–158.

56. Perry JD, Butterworth LA, Nicholson A, Appleby MR, Orr KE. 2003.Evaluation of a new chromogenic medium, Uri Select 4, for the isolationand identification of urinary tract pathogens. J Clin Pathol 56:528 –531.https://doi.org/10.1136/jcp.56.7.528.

57. Meddeb M, Maurer M, Grillon A, Scheftel JM, Jaulhac B. 2014. Compar-ison of routine use of two chromogenic media chromID CPS (bioMéri-eux) and UriSelect4 (Bio-Rad) for the detection of Escherichia coli andmajor uropathogenics in urine. Ann Biol Clin (Paris) 72:224 –230.

58. Aspevall O, Osterman B, Dittmer R, Stén L, Lindbäck E, Forsum U. 2002.Performance of four chromogenic urine culture media after one or twodays of incubation compared with reference media. J Clin Microbiol40:1500 –1503. https://doi.org/10.1128/JCM.40.4.1500-1503.2002.

59. Chang JC, Chien ML, Chen HM, Yan JJ, Wu JJ. 2008. Comparison of CPSID 3 and CHROMagar Orientation chromogenic agars with standardbiplate technique for culture of clinical urine samples. J MicrobiolImmunol Infect 41:422– 427.

60. Scarparo C, Piccoli P, Ricordi P, Scagnelli M. 2002. Comparative evalu-ation of two commercial chromogenic media for detection and pre-sumptive identification of urinary tract pathogens. Eur J Clin MicrobiolInfect Dis 21:283–289. https://doi.org/10.1007/s10096-002-0718-0.

61. Ciragil P, Gul M, Aral M, Ekerbicer H. 2006. Evaluation of a newchromogenic medium for isolation and identification of common uri-nary tract pathogens. Eur J Clin Microbiol Infect Dis 25:108 –111.https://doi.org/10.1007/s10096-006-0103-5.

62. Yarbrough ML, Wallace MA, Marshall C, Mathias E, Burnham CA. 31August 2016. Culture of urine specimens using chromID CPS Elitemedium can expedite Escherichia coli identification and reducehands-on time in the clinical laboratory. J Clin Microbiol https://doi.org/10.1128/JCM.01376-16.

63. Payne M, Roscoe D. 2015. Evaluation of two chromogenic media forthe isolation and identification of urinary tract pathogens. Eur J ClinMicrobiol Infect Dis 34:303–308. https://doi.org/10.1007/s10096-014-2235-3.

64. Rigaill J, Verhoeven PO, Mahinc C, Jeraiby M, Grattard F, Fonsale N,Pozzetto B, Carricajo A. 2015. Evaluation of new bioMérieux chromo-genic CPS media for detection of urinary tract pathogens. J Clin Micro-biol 53:2701–2702. https://doi.org/10.1128/JCM.00941-15.

65. Rasmussen M. 2016. Aerococcus: an increasingly acknowledged humanpathogen. Clin Microbiol Infect 22:22–27. https://doi.org/10.1016/j.cmi.2015.09.026.

66. Kuijper EJ, Barbut F, Brazier JS, Kleinkauf N, Eckmanns T, Lambert ML,Drudy D, Fitzpatrick F, Wiuff C, Brown DJ, Coia JE, Pituch H, Reichert P,Even J, Mossong J, Widmer AF, Olsen KE, Allerberger F, Notermans DW,Delmée M, Coignard B, Wilcox M, Patel B, Frei R, Nagy E, Bouza E, MarinM, Akerlund T, Virolainen-Julkunen A, Lyytikäinen O, Kotila S, Ingebre-tsen A, Smyth B, Rooney P, Poxton IR, Monnet DL. 2008. Update ofClostridium difficile infection due to PCR ribotype 027 in Europe, 2008.Euro Surveill 13(31):pii�18942. http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId�18942.

67. Delmée M, Van Broeck J, Simon A, Janssens M, Avesani V. 2005.Laboratory diagnosis of Clostridium difficile-associated diarrhoea: a plea




http://cmr.asm

.org/D

ownloaded from

https://doi.org/10.1128/JCM.42.8.3566-3569.2004

https://doi.org/10.1186/1471-2334-14-46

https://doi.org/10.1186/1471-2334-14-46

https://doi.org/10.1016/j.diagmicrobio.2008.03.007


https://doi.org/10.1128/JCM.00221-10

https://doi.org/10.1128/JCM.00221-10

https://doi.org/10.1186/1471-2334-10-285

https://doi.org/10.1128/JCM.01168-10



https://doi.org/10.1128/JCM.00251-13

https://doi.org/10.1099/jmm.0.066738-0

https://doi.org/10.1099/jmm.0.066738-0







https://doi.org/10.1128/JCM.02926-13

https://doi.org/10.1128/JCM.02926-13

https://doi.org/10.1097/PAT.0000000000000299

https://doi.org/10.1097/PAT.0000000000000299

https://doi.org/10.1111/j.1365-2672.2007.03442.x

https://doi.org/10.1111/j.1365-2672.2007.03442.x

https://doi.org/10.1007/s100960050403

https://doi.org/10.1007/s100960050403

https://doi.org/10.1046/j.1469-0691.2002.00433.x

https://doi.org/10.1136/jcp.56.8.608

https://doi.org/10.1136/jcp.56.8.608

https://doi.org/10.1136/jcp.56.7.528

https://doi.org/10.1128/JCM.40.4.1500-1503.2002

https://doi.org/10.1007/s10096-002-0718-0

https://doi.org/10.1007/s10096-006-0103-5

https://doi.org/10.1128/JCM.01376-16

https://doi.org/10.1128/JCM.01376-16

https://doi.org/10.1007/s10096-014-2235-3

https://doi.org/10.1007/s10096-014-2235-3

https://doi.org/10.1128/JCM.00941-15

https://doi.org/10.1016/j.cmi.2015.09.026


http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=18942

http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=18942

http://cmr.asm.org

http://cmr.asm.org/

for culture. J Med Microbiol 54:187–191. https://doi.org/10.1099/jmm.0.45844-0.

68. Eastwood K, Else P, Charlett A, Wilcox M. 2009. Comparison of ninecommercially available Clostridium difficile toxin detection assays, areal-time PCR assay for C. difficile tcdB, and a glutamate dehydro-genase detection assay to cytotoxin testing and cytotoxigenic cul-ture methods. J Clin Microbiol 47:3211–3217. https://doi.org/10.1128/JCM.01082-09.

69. Carson KC, Boseiwaqa LV, Thean SK, Foster NF, Riley TV. 2013. Isolationof Clostridium difficile from faecal specimens—a comparison of chro-mID C. difficile agar and cycloserine-cefoxitin-fructose agar. J MedMicrobiol 62:1423–1427. https://doi.org/10.1099/jmm.0.056515-0.

70. Eckert C, Burghoffer B, Lalande V, Barbut F. 2013. Evaluation of thechromogenic agar chromID C. difficile. J Clin Microbiol 51:1002–1004.https://doi.org/10.1128/JCM.02601-12.

71. Han SB, Chang J, Shin SH, Park KG, Lee GD, Park YG, Park YJ. 2014.Performance of chromID Clostridium difficile agar compared with BBL C.difficile selective agar for detection of C. difficile in stool specimens. AnnLab Med 34:376 –379. https://doi.org/10.3343/alm.2014.34.5.376.

72. Shin BM, Lee EJ. 2014. Comparison of chromID agar and Clostridiumdifficile selective agar for effective isolation of C. difficile from stoolspecimens. Ann Lab Med 34:15–19. https://doi.org/10.3343/alm.2014.34.1.15.

73. Yang JJ, Nam YS, Kim MJ, Cho SY, You E, Soh YS. 2014. Evaluation of achromogenic culture medium for the detection of Clostridium difficile.Yonsei Med J 55:994 –998. https://doi.org/10.3349/ymj.2014.55.4.994.

74. Chen JH, Cheng VC, Wong OY, Wong SC, So SY, Yam WC, Yuen KY. 11January 2016. The importance of matrix-assisted laser desorptionionization-time of flight mass spectrometry for correct identification ofClostridium difficile isolated from chromID C. difficile chromogenic agar.J Microbiol Immunol Infect https://doi.org/10.1016/j.jmii.2015.12.002.

75. Hill KA, Collins J, Wilson L, Perry JD, Gould FK. 2013. Comparison of twoselective media for the recovery of Clostridium difficile from environ-mental surfaces. J Hosp Infect 83:164 –166. https://doi.org/10.1016/j.jhin.2012.10.006.

76. Wilcox MH, Fawley WN, Parnell P. 2000. Value of lysozyme agar incor-poration and alkaline thioglycollate exposure for the environmentalrecovery of Clostridium difficile. J Hosp Infect 44:65– 69. https://doi.org/10.1053/jhin.1999.0253.

77. Park KS, Ki CS, Lee NY. 2015. Isolation and identification of Clostridiumdifficile using chromID C. difficile medium combined with Gram stain-ing and PRO disc testing: a proposal for a simple culture process. AnnLab Med 35:404 – 409. https://doi.org/10.3343/alm.2015.35.4.404.

78. Karpinski P, Pituch H, Lachowicz D, Piotrowski M, Obuch-WoszczatynskiP. 2015. Evaluation of growth of clinical Clostridium difficile strainsbelonging to different PCR-ribotypes on chromID C. difficile agar. MedDosw Mikrobiol 67:9 –14.

79. Connor MC, Fairley DJ, McKenna JP, Marks NJ, McGrath JW. 2016.Clostridium difficile ribotype 023 lacks the ability to hydrolyse esculin,leading to false-negative results on chromogenic agar. J Clin Microbiol54:1404 –1405. https://doi.org/10.1128/JCM.00234-16.

80. Reller ME, Lema CA, Perl TM, Cai M, Ross TL, Speck KA, Carroll KC. 2007.Yield of stool culture with isolate toxin testing versus a two-stepalgorithm including stool toxin testing for detection of toxigenic Clos-tridium difficile. J Clin Microbiol 45:3601–3605. https://doi.org/10.1128/JCM.01305-07.

81. Darkoh C, Dupont HL, Kaplan HB. 2011. Novel one-step method fordetection and isolation of active-toxin-producing Clostridium difficilestrains directly from stool samples. J Clin Microbiol 49:4219 – 4224.https://doi.org/10.1128/JCM.01033-11.

82. Dalziel L, Payne M, Perry JD. 2014. CASA chromogenic agar: an optimalmedium for the isolation of clinically important Campylobacter spp.from stool samples, abstr P0748. Abstr 24th Eur Congr Clin MicrobiolInfect Dis https://www.escmid.org/escmid_publications/escmid_elibrary/material/?mid�16600.

83. van Dijk S, Bruins MJ, Ruijs GJ. 2009. Evaluation and implementation ofa chromogenic agar medium for Salmonella detection in stool inroutine laboratory diagnostics. J Clin Microbiol 47:456 – 458. https://doi.org/10.1128/JCM.01643-08.

84. Martiny D, Dediste A, Anglade C, Vlaes L, Moens C, Mohamed S,Vandenberg O. 2016. Performance of the chromID Salmonella Elitechromogenic agar in comparison with CHROMagar™ Salmonella, Ox-oid™ Brilliance™ Salmonella and Hektoen agars for the isolation of

Salmonella from stool specimens. Diagn Microbiol Infect Dis 86:128 –130. https://doi.org/10.1016/j.diagmicrobio.2016.07.021.

85. Butterworth LA, Perry JD, Davies G, Burton M, Reed RH, Gould FK. 2004.Evaluation of novel beta-ribosidase substrates for the differentiation ofGram-negative bacteria. J Appl Microbiol 96:170 –176. https://doi.org/10.1046/j.1365-2672.2003.02130.x.

86. Wylie JL, Van Caeseele P, Gilmour MW, Sitter D, Guttek C, Giercke S.2013. Evaluation of a new chromogenic agar medium for detection ofShiga toxin-producing Escherichia coli (STEC) and relative prevalencesof O157 and non-O157 STEC in Manitoba, Canada. J Clin Microbiol51:466 – 471. https://doi.org/10.1128/JCM.02329-12.

87. Gouali M, Ruckly C, Carle I, Lejay-Collin M, Weill FX. 2013. Evaluation ofCHROMagar STEC and STEC O104 chromogenic agar media for detec-tion of Shiga toxin-producing Escherichia coli in stool specimens. J ClinMicrobiol 51:894 –900. https://doi.org/10.1128/JCM.03121-12.

88. Bettelheim KA. 1998. Studies of Escherichia coli cultured on RainbowAgar O157 with particular reference to enterohaemorrhagic Escherichiacoli (EHEC). Microbiol Immunol 42:265–269. https://doi.org/10.1111/j.1348-0421.1998.tb02282.x.

89. Zelyas N, Poon A, Patterson-Fortin L, Johnson RP, Lee W, Chui L. 2016.Assessment of commercial chromogenic solid media for the detectionof non-O157 Shiga toxin-producing Escherichia coli (STEC). Diagn Mi-crobiol Infect Dis 85:302–308. https://doi.org/10.1016/j.diagmicrobio.2016.03.013.

90. Hirvonen JJ, Siitonen A, Kaukoranta SS. 2012. Usability and perfor-mance of CHROMagar STEC medium in detection of Shiga toxin-producing Escherichia coli strains. J Clin Microbiol 50:3586 –3590.https://doi.org/10.1128/JCM.01754-12.

91. McCallum C, McGregor A, Vanniasinkam T. 2013. Prevalence of Shigatoxin-producing Escherichia coli (STEC) in Tasmania, Australia. Pathol-ogy 45:681– 688. https://doi.org/10.1097/PAT.0000000000000000.

92. Eddabra R, Piemont Y, Scheftel JM. 2011. Evaluation of a new chromo-genic medium, chromID Vibrio, for the isolation and presumptiveidentification of Vibrio cholerae and Vibrio parahaemolyticus from hu-man clinical specimens. Eur J Clin Microbiol Infect Dis 30:733–737.https://doi.org/10.1007/s10096-010-1145-2.

93. Weagant SD. 2008. A new chromogenic agar medium for detection ofpotentially virulent Yersinia enterocolitica. J Microbiol Methods 72:185–190. https://doi.org/10.1016/j.mimet.2007.11.019.

94. Fondrevez M, Labbé A, Houard E, Fravalo P, Madec F, Denis M. 2010. Asimplified method for detecting pathogenic Yersinia enterocolitica inslaughtered pig tonsils. J Microbiol Methods 83:244 –249. https://doi.org/10.1016/j.mimet.2010.09.012.

95. Karhukorpi J, Päivänurmi M. 2014. Differentiation of Yersinia enteroco-litica biotype 1A from pathogenic Yersinia enterocolitica biotypes bydetection of �-glucosidase activity: comparison of two chromogenicculture media and Vitek2. J Med Microbiol 63:34 –37. https://doi.org/10.1099/jmm.0.062521-0.

96. Denis M, Houard E, Labbé A, Fondrevez M, Salvat G. 2011. A selectivechromogenic plate, YECA, for the detection of pathogenic Yersiniaenterocolitica: specificity, sensitivity, and capacity to detect pathogenicY. enterocolitica from pig tonsils. J Pathog 2011:296275. https://doi.org/10.4061/2011/296275.

97. Robotham JV, Deeny SR, Fuller C, Hopkins S, Cookson B, Stone S. 2016.Cost-effectiveness of national mandatory screening of all admissions toEnglish National Health Service hospitals for meticillin-resistant Staph-ylococcus aureus: a mathematical modelling study. Lancet Infect Dis16:348 –356. https://doi.org/10.1016/S1473-3099(15)00417-X.

98. Perry JD, Davies A, Butterworth LA, Hopley AL, Nicholson A, Gould FK.2004. Development and evaluation of a chromogenic agar medium formethicillin-resistant Staphylococcus aureus. J Clin Microbiol 42:4519 – 4523. https://doi.org/10.1128/JCM.42.10.4519-4523.2004.

99. Diederen B, van Duijn I, van Belkum A, Willemse P, van Keulen P,Kluytmans J. 2005. Performance of CHROMagar MRSA medium fordetection of methicillin-resistant Staphylococcus aureus. J Clin Microbiol43:1925–1927. https://doi.org/10.1128/JCM.43.4.1925-1927.2005.

100. Nonhoff C, Denis O, Brenner A, Buidin P, Legros N, Thiroux C, DramaixM, Struelens MJ. 2009. Comparison of three chromogenic media andenrichment broth media for the detection of methicillin-resistantStaphylococcus aureus from mucocutaneous screening specimens:comparison of MRSA chromogenic media. Eur J Clin Microbiol Infect Dis28:363–369. https://doi.org/10.1007/s10096-008-0637-9.

101. Wolk DM, Marx JL, Dominguez L, Driscoll D, Schifman RB. 2009. Com-parison of MRSASelect agar, CHROMagar methicillin-resistant Staphylo-




http://cmr.asm

.org/D

ownloaded from

https://doi.org/10.1099/jmm.0.45844-0

https://doi.org/10.1099/jmm.0.45844-0

https://doi.org/10.1128/JCM.01082-09

https://doi.org/10.1128/JCM.01082-09

https://doi.org/10.1099/jmm.0.056515-0

https://doi.org/10.1128/JCM.02601-12

https://doi.org/10.3343/alm.2014.34.5.376

https://doi.org/10.3343/alm.2014.34.1.15

https://doi.org/10.3343/alm.2014.34.1.15

https://doi.org/10.3349/ymj.2014.55.4.994

https://doi.org/10.1016/j.jmii.2015.12.002

https://doi.org/10.1016/j.jhin.2012.10.006


https://doi.org/10.1053/jhin.1999.0253

https://doi.org/10.1053/jhin.1999.0253

https://doi.org/10.3343/alm.2015.35.4.404

https://doi.org/10.1128/JCM.00234-16

https://doi.org/10.1128/JCM.01305-07

https://doi.org/10.1128/JCM.01305-07

https://doi.org/10.1128/JCM.01033-11

https://www.escmid.org/escmid_publications/escmid_elibrary/material/?mid=16600


https://doi.org/10.1128/JCM.01643-08

https://doi.org/10.1128/JCM.01643-08


https://doi.org/10.1046/j.1365-2672.2003.02130.x

https://doi.org/10.1046/j.1365-2672.2003.02130.x

https://doi.org/10.1128/JCM.02329-12

https://doi.org/10.1128/JCM.03121-12

https://doi.org/10.1111/j.1348-0421.1998.tb02282.x

https://doi.org/10.1111/j.1348-0421.1998.tb02282.x



https://doi.org/10.1128/JCM.01754-12

https://doi.org/10.1097/PAT.0000000000000000

https://doi.org/10.1007/s10096-010-1145-2




https://doi.org/10.1099/jmm.0.062521-0

https://doi.org/10.1099/jmm.0.062521-0

https://doi.org/10.4061/2011/296275

https://doi.org/10.4061/2011/296275

https://doi.org/10.1016/S1473-3099(15)00417-X

https://doi.org/10.1128/JCM.42.10.4519-4523.2004

https://doi.org/10.1128/JCM.43.4.1925-1927.2005

https://doi.org/10.1007/s10096-008-0637-9

http://cmr.asm.org

http://cmr.asm.org/

coccus aureus (MRSA) medium, and Xpert MRSA PCR for detection ofMRSA in nares: diagnostic accuracy for surveillance samples with var-ious bacterial densities. J Clin Microbiol 47:3933–3936. https://doi.org/10.1128/JCM.00601-09.

102. Malhotra-Kumar S, Abrahantes JC, Sabiiti W, Lammens C, VercauterenG, Ieven M, Molenberghs G, Aerts M, Goossens H, MOSAR WP2 StudyTeam. 2010. Evaluation of chromogenic media for detection ofmethicillin-resistant Staphylococcus aureus. J Clin Microbiol 48:1040 –1046. https://doi.org/10.1128/JCM.01745-09.

103. Bischof LJ, Lapsley L, Fontecchio K, Jacosalem D, Young C, Hankerd R,Newton DW. 2009. Comparison of chromogenic media to BD GeneOhmmethicillin-resistant Staphylococcus aureus (MRSA) PCR for detection ofMRSA in nasal swabs. J Clin Microbiol 47:2281–2283. https://doi.org/10.1128/JCM.02256-08.

104. Gazin M, Lee A, Derde L, Kazma M, Lammens C, Ieven M, Bonten M,Carmeli Y, Harbarth S, Brun-Buisson C, Goossens H, Malhotra-Kumar S,MOSAR WP2 Study Team. 2012. Culture-based detection of methicillin-resistant Staphylococcus aureus by a network of European laboratories:an external quality assessment study. Eur J Clin Microbiol Infect Dis31:1765–1770. https://doi.org/10.1007/s10096-011-1499-0.

105. Luteijn JM, Hubben GA, Pechlivanoglou P, Bonten MJ, Postma MJ. 2011.Diagnostic accuracy of culture-based and PCR-based detection tests formethicillin-resistant Staphylococcus aureus: a meta-analysis. Clin Micro-biol Infect 17:146 –154. https://doi.org/10.1111/j.1469-0691.2010.03202.x.

106. Yang HY, Suh JT, Lee HJ. 2010. Evaluation of commercial selective agarsin screening for methicillin-resistant Staphylococcus aureus. Ann ClinLab Sci 40:252–256.

107. Morris K, Wilson C, Wilcox MH. 2012. Evaluation of chromogenicmeticillin-resistant Staphylococcus aureus media: sensitivity versus turn-around time. J Hosp Infect 81:20 –24. https://doi.org/10.1016/j.jhin.2012.02.003.

108. Denys GA, Renzi PB, Koch KM, Wissel CM. 2013. Three-way comparisonof BBL CHROMagar MRSA II, MRSA Select, and Spectra MRSA fordetection of methicillin-resistant Staphylococcus aureus isolates in nasalsurveillance cultures. J Clin Microbiol 51:202–205. https://doi.org/10.1128/JCM.02022-12.

109. Veenemans J, Verhulst C, Punselie R, van Keulen PH, Kluytmans JA.2013. Evaluation of Brilliance MRSA 2 agar for detection of methicillin-resistant Staphylococcus aureus in clinical samples. J Clin Microbiol51:1026 –1027. https://doi.org/10.1128/JCM.02995-12.

110. Dodémont M, Verhulst C, Nonhoff C, Nagant C, Denis O, Kluytmans J.2015. Prospective two-center comparison of three chromogenic agarsfor methicillin-resistant Staphylococcus aureus screening in hospitalizedpatients. J Clin Microbiol 53:3014 –3016. https://doi.org/10.1128/JCM.01006-15.

111. Delmas J, Robin F, Schweitzer C, Lesens O, Bonnet R. 2007. Evaluationof a new chromogenic medium, chromID VRE, for detection ofvancomycin-resistant enterococci in stool samples and rectal swabs. JClin Microbiol 45:2731–2733. https://doi.org/10.1128/JCM.00448-07.

112. Ledeboer NA, Tibbetts RJ, Dunne WM. 2007. A new chromogenic agarmedium, chromID VRE, to screen for vancomycin-resistant Enterococcusfaecium and Enterococcus faecalis. Diagn Microbiol Infect Dis 59:477– 479. https://doi.org/10.1016/j.diagmicrobio.2007.06.018.

113. Grabsch EA, Ghaly-Derias S, Gao W, Howden BP. 2008. Comparativestudy of selective chromogenic (chromID VRE) and bile esculin agarsfor isolation and identification of vanB-containing vancomycin-resistant enterococci from feces and rectal swabs. J Clin Microbiol46:4034 – 4036. https://doi.org/10.1128/JCM.00944-08.

114. Cuzon G, Naas T, Fortineau N, Nordmann P. 2008. Novel chromogenicmedium for detection of vancomycin-resistant Enterococcus faeciumand Enterococcus faecalis. J Clin Microbiol 46:2442–2444. https://doi.org/10.1128/JCM.00492-08.

115. Asir K, Wilkinson K, Perry JD, Reed RH, Gould FK. 2009. Evaluation ofchromogenic media for the isolation of vancomycin-resistant entero-cocci from stool samples. Lett Appl Microbiol 48:230 –233. https://doi.org/10.1111/j.1472-765X.2008.02517.x.

116. Ongut G, Kilinckaya H, Baysan BO, Ogunc D, Colak D, Inan D, KasarogluK, Gunseren F. 2013. Evaluation of Brilliance VRE agar for the detectionof vancomycin-resistant enterococci in rectal swab specimens. J MedMicrobiol 62:661– 662. https://doi.org/10.1099/jmm.0.052845-0.

117. Kallstrom G, Doern CD, Dunne WM, Jr. 2010. Evaluation of a chromo-genic agar under development to screen for VRE colonization. J ClinMicrobiol 48:999 –1001. https://doi.org/10.1128/JCM.02011-09.

118. Stamper PD, Shulder S, Bekalo P, Manandhar D, Ross TL, Speser S,Kingery J, Carroll KC. 2010. Evaluation of BBL CHROMagar VanRE fordetection of vancomycin-resistant enterococci in rectal swab speci-mens. J Clin Microbiol 48:4294 – 4297. https://doi.org/10.1128/JCM.01522-10.

119. Peterson JF, Doern CD, Kallstrom G, Riebe KM, Sander T, Dunne WM, Jr,Ledeboer NA. 2010. Evaluation of Spectra VRE, a new chromogenicagar medium designed to screen for vancomycin-resistant Enterococ-cus faecalis and Enterococcus faecium. J Clin Microbiol 48:4627– 4629.https://doi.org/10.1128/JCM.01676-10.

120. Jenkins SG, Raskoshina L, Schuetz AN. 2011. Comparison of perfor-mance of the novel chromogenic Spectra VRE agar to that of bileesculin azide and Campylobacter agars for detection of vancomycin-resistant enterococci in fecal samples. J Clin Microbiol 49:3947–3949.https://doi.org/10.1128/JCM.00180-11.

121. Nguyen TD, Evans KD, Goh RA, Tan GL, Peterson EM. 2012. Comparisonof medium, temperature, and length of incubation for detection ofvancomycin-resistant Enterococcus. J Clin Microbiol 50:2503–2505.https://doi.org/10.1128/JCM.00479-12.

122. Anderson NW, Buchan BW, Young CL, Newton DW, Brenke C, Lapsley L,Granato PA, Ledeboer NA. 2013. Multicenter clinical evaluation ofVRESelect agar for identification of vancomycin-resistant Enterococcusfaecalis and Enterococcus faecium. J Clin Microbiol 51:2758 –2760.https://doi.org/10.1128/JCM.00979-13.

123. Peltroche-Llacsahuanga H, Top J, Weber-Heynemann J, Lütticken R,Haase G. 2009. Comparison of two chromogenic media for selectiveisolation of vancomycin-resistant enterococci from stool specimens. JClin Microbiol 47:4113– 4116. https://doi.org/10.1128/JCM.00882-09.

124. Suwantarat N, Roberts A, Prestridgem J, Seeleym R, Speser S, HarmonC, Zhang C, Henciak S, Stamper PD, Ross T, Carroll KC. 2014. Compar-ison of five chromogenic media for recovery of vancomycin-resistantenterococci from fecal samples. J Clin Microbiol 52:4039 – 4042. https://doi.org/10.1128/JCM.00151-14.

125. Gouliouris T, Blane B, Brodrick HJ, Raven KE, Ambridge KE, Kidney AD,Hadjirin NF, Török ME, Limmathurotsakul D, Peacock SJ. 2016. Com-parison of two chromogenic media for the detection of vancomycin-resistant enterococcal carriage by nursing home residents. Diagn Mi-crobiol Infect Dis 85:409 – 412. https://doi.org/10.1016/j.diagmicrobio.2016.04.026.

126. Frickmann H, Masanta WO, Zautner AE. 2014. Emerging rapid resis-tance testing methods for clinical microbiology laboratories and theirpotential impact on patient management. Biomed Res Int 2014:375681.https://doi.org/10.1155/2014/375681.

127. Haller S, Eller C, Hermes J, Kaase M, Steglich M, Radonic A, DabrowskiPW, Nitsche A, Pfeifer Y, Werner G, Wunderle W, Velasco E, Abu Sin M,Eckmanns T, Nübel U. 2015. What caused the outbreak of ESBL-producing Klebsiella pneumoniae in a neonatal intensive care unit,Germany 2009 to 2012? Reconstructing transmission with epidemio-logical analysis and whole-genome sequencing. BMJ Open 5:e007397.https://doi.org/10.1136/bmjopen-2014-007397.

128. Réglier-Poupet H, Naas T, Carrer A, Cady A, Adam JM, Fortineau N,Poyart C, Nordmann P. 2008. Performance of chromID ESBL, a chromo-genic medium for detection of Enterobacteriaceae producingextended-spectrum beta-lactamases. J Med Microbiol 57:310 –315.https://doi.org/10.1099/jmm.0.47625-0.

129. Huang TD, Bogaerts P, Berhin C, Guisset A, Glupczynski Y. 2010. Eval-uation of Brilliance ESBL agar, a novel chromogenic medium for de-tection of extended-spectrum-beta-lactamase-producing Enterobacte-riaceae. J Clin Microbiol 48:2091–2096. https://doi.org/10.1128/JCM.02342-09.

130. Paniagua R, Valverde A, Coque TM, Baquero F, Cantón R. 2010. Assess-ment of prevalence and changing epidemiology of extended-spectrum�-lactamase-producing Enterobacteriaceae fecal carriers using a chro-mogenic medium. Diagn Microbiol Infect Dis 67:376 –379. https://doi.org/10.1016/j.diagmicrobio.2010.03.012.

131. Saito R, Koyano S, Nagai R, Okamura N, Moriya K, Koike K. 2010.Evaluation of a chromogenic agar medium for the detection ofextended-spectrum �-lactamase-producing Enterobacteriaceae. LettAppl Microbiol 51:704 –706. https://doi.org/10.1111/j.1472-765X.2010.02945.x.

132. Willems E, Cartuyvels R, Magerman K, Verhaegen J. 2013. Evaluation of3 different agar media for rapid detection of extended-spectrum�-lactamase-producing Enterobacteriaceae from surveillance samples.




http://cmr.asm

.org/D

ownloaded from

https://doi.org/10.1128/JCM.00601-09

https://doi.org/10.1128/JCM.00601-09

https://doi.org/10.1128/JCM.01745-09

https://doi.org/10.1128/JCM.02256-08

https://doi.org/10.1128/JCM.02256-08

https://doi.org/10.1007/s10096-011-1499-0

https://doi.org/10.1111/j.1469-0691.2010.03202.x

https://doi.org/10.1111/j.1469-0691.2010.03202.x



https://doi.org/10.1128/JCM.02022-12

https://doi.org/10.1128/JCM.02022-12

https://doi.org/10.1128/JCM.02995-12

https://doi.org/10.1128/JCM.01006-15

https://doi.org/10.1128/JCM.01006-15

https://doi.org/10.1128/JCM.00448-07


https://doi.org/10.1128/JCM.00944-08

https://doi.org/10.1128/JCM.00492-08

https://doi.org/10.1128/JCM.00492-08

https://doi.org/10.1111/j.1472-765X.2008.02517.x

https://doi.org/10.1111/j.1472-765X.2008.02517.x

https://doi.org/10.1099/jmm.0.052845-0

https://doi.org/10.1128/JCM.02011-09

https://doi.org/10.1128/JCM.01522-10

https://doi.org/10.1128/JCM.01522-10

https://doi.org/10.1128/JCM.01676-10

https://doi.org/10.1128/JCM.00180-11

https://doi.org/10.1128/JCM.00479-12

https://doi.org/10.1128/JCM.00979-13

https://doi.org/10.1128/JCM.00882-09

https://doi.org/10.1128/JCM.00151-14

https://doi.org/10.1128/JCM.00151-14



https://doi.org/10.1155/2014/375681

https://doi.org/10.1136/bmjopen-2014-007397

https://doi.org/10.1099/jmm.0.47625-0

https://doi.org/10.1128/JCM.02342-09

https://doi.org/10.1128/JCM.02342-09



https://doi.org/10.1111/j.1472-765X.2010.02945.x

https://doi.org/10.1111/j.1472-765X.2010.02945.x

http://cmr.asm.org

http://cmr.asm.org/

Diagn Microbiol Infect Dis 76:16 –19. https://doi.org/10.1016/j.diagmicrobio.2013.02.013.

133. Grohs P, Tillecovidin B, Caumont-Prim A, Carbonnelle E, Day N, Podg-lajen I, Gutmann L. 2013. Comparison of five media for detection ofextended-spectrum beta-lactamase by use of the wasp instrument forautomated specimen processing. J Clin Microbiol 51:2713–2716.https://doi.org/10.1128/JCM.00077-13.

134. Blane B, Brodrick HJ, Gouliouris T, Ambridge KE, Kidney AD, Ludden CM,Limmathurotsakul D, Török ME, Peacock SJ. 2016. Comparison of 2chromogenic media for the detection of extended-spectrum�-lactamase producing Enterobacteriaceae stool carriage in nursinghome residents. Diagn Microbiol Infect Dis 84:181–183. https://doi.org/10.1016/j.diagmicrobio.2015.11.008.

135. Tängdén T, Giske CG. 2015. Global dissemination of extensively drug-resistant carbapenemase-producing Enterobacteriaceae: clinical per-spectives on detection, treatment and infection control. J Intern Med277:501–512. https://doi.org/10.1111/joim.12342.

136. Findlay J, Hopkins KL, Meunier D, Woodford N. 2015. Evaluation ofthree commercial assays for rapid detection of genes encoding clini-cally relevant carbapenemases in cultured bacteria. J Antimicrob Che-mother 70:1338 –1342. https://doi.org/10.1093/jac/dku571.

137. Swaminathan M, Sharma S, Poliansky Blash S, Patel G, Banach DB,Phillips M, LaBombardi V, Anderson KF, Kitchel B, Srinivasan A, CalfeeDP. 2013. Prevalence and risk factors for acquisition of carbapenem-resistant Enterobacteriaceae in the setting of endemicity. Infect ControlHosp Epidemiol 34:809 – 817. https://doi.org/10.1086/671270.

138. Centers for Disease Control and Prevention. 2009. Guidance for controlof infections with carbapenem-resistant or carbapenemase-producingEnterobacteriaceae in acute care facilities. MMWR Morb Mortal WklyRep 58:256 –260.

139. Centers for Disease Control and Prevention. 2009. Laboratory protocolfor detection of carbapenem-resistant or carbapenemase-producing,Klebsiella spp. and E. coli from rectal swabs. Centers for Disease Controland Prevention, Atlanta, GA. http://www.cdc.gov/HAI/pdfs/labSettings/Klebsiella_or_Ecoli.pdf. Accessed, 5 April 2016.

140. Viau R, Frank KM, Jacobs MR, Wilson B, Kaye K, Donskey CJ, Perez F,Endimiani A, Bonomo RA. 2016. Intestinal carriage of carbapenemase-producing organisms: current status of surveillance methods. Clin Mi-crobiol Rev 29:1–27. https://doi.org/10.1128/CMR.00108-14.

141. Perry JD, Naqvi SH, Mirza IA, Alizai SA, Hussain A, Ghirardi S, Orenga S,Wilkinson K, Woodford N, Zhang J, Livermore DM, Abbasi SA, Raza MW.2011. Prevalence of faecal carriage of Enterobacteriaceae with NDM-1carbapenemase at military hospitals in Pakistan, and evaluation of twochromogenic media. J Antimicrob Chemother 66:2288 –2294. https://doi.org/10.1093/jac/dkr299.

142. Moran Gilad J, Carmeli Y, Schwartz D, Navon-Venezia S. 2011. Labora-tory evaluation of the CHROMagar KPC medium for identification ofcarbapenem-nonsusceptible Enterobacteriaceae. Diagn Microbiol InfectDis 70:565–567. https://doi.org/10.1016/j.diagmicrobio.2010.03.005.

143. Nordmann P, Poirel L, Carrër A, Toleman MA, Walsh TR. 2011. How todetect NDM-1 producers. J Clin Microbiol 49:718 –721. https://doi.org/10.1128/JCM.01773-10.

144. Wilkinson KM, Winstanley TG, Lanyon C, Cummings SP, Raza MW, PerryJD. 2012. Comparison of four chromogenic culture media forcarbapenemase-producing Enterobacteriaceae. J Clin Microbiol 50:3102–3104. https://doi.org/10.1128/JCM.01613-12.

145. Bracco S, Migliavacca R, Pini B, Corbo N, Nucleo E, Brigante G, Piazza A,Micheletti P, Luzzaro F. 2013. Evaluation of Brilliance CRE agar for thedetection of carbapenem-resistant Gram-negative bacteria. New Micro-biol 36:181–186.

146. Cohen Stuart J, Voets G, Rottier W, Voskuil S, Scharringa J, Dijk KV, FluitAC, Leverstein-Van Hall M. 2013. Evaluation of the Oxoid Brilliance CREagar for the detection of carbapenemase-producing Enterobacteria-ceae. Eur J Clin Microbiol Infect Dis 32:1445–1449. https://doi.org/10.1007/s10096-013-1896-7.

147. Girlich D, Poirel L, Nordmann P. 2013. Comparison of the SUPERCARBA,CHROMagar KPC, and Brilliance CRE screening media for detection ofEnterobacteriaceae with reduced susceptibility to carbapenems. DiagnMicrobiol Infect Dis 75:214 –217. https://doi.org/10.1016/j.diagmicrobio.2012.10.006.

148. Girlich D, Anglade C, Zambardi G, Nordmann P. 2013. Comparativeevaluation of a novel chromogenic medium (chromID OXA-48) fordetection of OXA-48 producing Enterobacteriaceae. Diagn Microbiol

Infect Dis 77:296 –300. https://doi.org/10.1016/j.diagmicrobio.2013.08.015.

149. Girlich D, Bouihat N, Poirel L, Benouda A, Nordmann P. 2014. High rateof faecal carriage of extended-spectrum �-lactamase and OXA-48carbapenemase-producing Enterobacteriaceae at a university hospitalin Morocco. Clin Microbiol Infect 20:350 –354. https://doi.org/10.1111/1469-0691.12325.

150. Hornsey M, Phee L, Woodford N, Turton J, Meunier D, Thomas C,Wareham DW. 2013. Evaluation of three selective chromogenic media,CHROMagar ESBL, CHROMagar CTX-M and CHROMagar KPC, for thedetection of Klebsiella pneumoniae producing OXA-48 carbapenemase.J Clin Pathol 66:348 –350. https://doi.org/10.1136/jclinpath-2012-201234.

151. Simner PJ, Gilmour MW, DeGagne P, Nichol K, Karlowsky JA. 2015.Evaluation of five chromogenic agar media and the Rosco Rapid Carbscreen kit for detection and confirmation of carbapenemase produc-tion in Gram-negative bacilli. J Clin Microbiol 53:105–112. https://doi.org/10.1128/JCM.02068-14.

152. Adler A, Navon-Venezia S, Moran-Gilad J, Marcos E, Schwartz D, CarmeliY. 2011. Laboratory and clinical evaluation of screening agar plates fordetection of carbapenem-resistant Enterobacteriaceae from surveil-lance rectal swabs. J Clin Microbiol 49:2239 –2242. https://doi.org/10.1128/JCM.02566-10.

153. Panagea T, Galani I, Souli M, Adamou P, Antoniadou A, Giamarellou H.2011. Evaluation of CHROMagar™ KPC for the detection ofcarbapenemase-producing Enterobacteriaceae in rectal surveillancecultures. Int J Antimicrob Agents 37:124 –128. https://doi.org/10.1016/j.ijantimicag.2010.10.010.

154. Vrioni G, Daniil I, Voulgari E, Ranellou K, Koumaki V, Ghirardi S, KimouliM, Zambardi G, Tsakris A. 2012. Comparative evaluation of a prototypechromogenic medium (ChromID CARBA) for detecting carbapenemase-producing Enterobacteriaceae in surveillance rectal swabs. J Clin Micro-biol 50:1841–1846. https://doi.org/10.1128/JCM.06848-11.

155. Vasoo S, Lolans K, Li H, Prabaker K, Hayden MK. 2014. Comparison ofthe CHROMagar™ KPC, Remel Spectra™ CRE, and a direct ertapenemdisk method for the detection of KPC-producing Enterobacteriaceaefrom perirectal swabs. Diagn Microbiol Infect Dis 78:356 –359. https://doi.org/10.1016/j.diagmicrobio.2013.08.016.

156. Papadimitriou-Olivgeris M, Bartzavali C, Christofidou M, Bereksi N, HeyJ, Zambardi G, Spiliopoulou I. 2014. Performance of chromID® CARBAmedium for carbapenemases-producing Enterobacteriaceae detectionduring rectal screening. Eur J Clin Microbiol Infect Dis 33:35– 40. https://doi.org/10.1007/s10096-013-1925-6.

157. Zarakolu P, Day KM, Sidjabat HE, Kamolvit W, Lanyon CV, Cummings SP,Paterson DL, Akova M, Perry JD. 2015. Evaluation of a new chromo-genic medium, chromID OXA-48, for recovery of carbapenemase-producing Enterobacteriaceae from patients at a university hospital inTurkey. Eur J Clin Microbiol Infect Dis 34:519 –525. https://doi.org/10.1007/s10096-014-2255-z.

158. Davies F, Donaldson H, Shibu P, Dronavalli J, Bartholomew N, Rebec M,Goonesekera S, Mookerjee S, Otter J. 2016. Abstr 26th Eur Congr ClinMicrobiol Infect Dis, abstr P1018. Evaluation of different media forintroduction of a CPE-screening programme at a UK hospital. https://www.escmid.org/escmid_publications/escmid_elibrary/material/?mid�35639.

159. Papadimitriou-Olivgeris M, Vamvakopoulou S, Spyropoulou A, Bartza-vali C, Marangos M, Anastassiou ED, Spiliopoulou I, Christofidou M. 19July 2016. Performance of four different agar plate methods for rectalswabs, synergy disk tests, and MBL-Etest for clinical isolates in detect-ing carbapenemase-producing Klebsiella pneumoniae. J Med Microbiolhttps://doi.org/10.1099/jmm.0.000318.

160. Day KM, Ali S, Mirza IA, Sidjabat HE, Silvey A, Lanyon CV, Cummings SP,Abbasi SA, Raza MW, Paterson DL, Perry JD. 2013. Prevalence andmolecular characterization of Enterobacteriaceae producing NDM-1 car-bapenemase at a military hospital in Pakistan and evaluation of twochromogenic media. Diagn Microbiol Infect Dis 75:187–191. https://doi.org/10.1016/j.diagmicrobio.2012.11.006.

161. Day KM, Salman M, Kazi B, Sidjabat HE, Silvey A, Lanyon CV, CummingsSP, Ali MN, Raza MW, Paterson DL, Perry JD. 2013. Prevalence of NDM-1carbapenemase in patients with diarrhoea in Pakistan and evaluationof two chromogenic culture media. J Appl Microbiol 114:1810 –1816.https://doi.org/10.1111/jam.12171.

162. Heinrichs A, Nonhoff C, Roisin S, De Mendonça R, Adam AS, DodémontM, Denis O. 2016. Comparison of two chromogenic media and enrich-




http://cmr.asm

.org/D

ownloaded from



https://doi.org/10.1128/JCM.00077-13



https://doi.org/10.1111/joim.12342

https://doi.org/10.1093/jac/dku571

https://doi.org/10.1086/671270

http://www.cdc.gov/HAI/pdfs/labSettings/Klebsiella_or_Ecoli.pdf

http://www.cdc.gov/HAI/pdfs/labSettings/Klebsiella_or_Ecoli.pdf

https://doi.org/10.1128/CMR.00108-14

https://doi.org/10.1093/jac/dkr299

https://doi.org/10.1093/jac/dkr299


https://doi.org/10.1128/JCM.01773-10

https://doi.org/10.1128/JCM.01773-10

https://doi.org/10.1128/JCM.01613-12

https://doi.org/10.1007/s10096-013-1896-7

https://doi.org/10.1007/s10096-013-1896-7





https://doi.org/10.1111/1469-0691.12325

https://doi.org/10.1111/1469-0691.12325

https://doi.org/10.1136/jclinpath-2012-201234

https://doi.org/10.1136/jclinpath-2012-201234

https://doi.org/10.1128/JCM.02068-14

https://doi.org/10.1128/JCM.02068-14

https://doi.org/10.1128/JCM.02566-10

https://doi.org/10.1128/JCM.02566-10

https://doi.org/10.1016/j.ijantimicag.2010.10.010

https://doi.org/10.1016/j.ijantimicag.2010.10.010

https://doi.org/10.1128/JCM.06848-11



https://doi.org/10.1007/s10096-013-1925-6

https://doi.org/10.1007/s10096-013-1925-6

https://doi.org/10.1007/s10096-014-2255-z

https://doi.org/10.1007/s10096-014-2255-z




https://doi.org/10.1099/jmm.0.000318



https://doi.org/10.1111/jam.12171

http://cmr.asm.org

http://cmr.asm.org/

ment broth for the detection of carbapenemase-producing Enterobac-teriaceae on screening rectal swabs from hospitalized patients. J MedMicrobiol 65:438 – 441. https://doi.org/10.1099/jmm.0.000244.

163. Nordmann P, Girlich D, Poirel L. 2012. Detection of carbapenemaseproducers in Enterobacteriaceae by use of a novel screening medium. JClin Microbiol 50:2761–2766. https://doi.org/10.1128/JCM.06477-11.

164. García Quintanilla M, Poirel L, Nordmann P. 2016. Abstr 26th Eur CongrClin Microbiol Infect Dis, abstr EV0405. CHROMagar mSuperCarbascreening followed by Rapidec Carba NP test for detection of carbap-enemase producers in Enterobacteriaceae. https://www.escmid.org/escmid_publications/escmid_elibrary/material/?mid�34461.

165. García-Fernández S, Hernández-García M, Valverde A, Ruiz-Garbajosa P,Morosini MI, Cantón R. 2016. CHROMagar mSuperCARBA performancein carbapenem-resistant Enterobacteriaceae isolates characterized atmolecular level and routine surveillance rectal swab specimens. DiagnMicrobiol Infect Dis https://doi.org/10.1016/j.diagmicrobio.2016.11.014.

166. Mathers AJ, Poulter M, Dirks D, Carroll J, Sifri CD, Hazen KC. 2014.Clinical microbiology costs for methods of active surveillance for Kleb-siella pneumoniae carbapenemase-producing Enterobacteriaceae. InfectControl Hosp Epidemiol 35:350 –355. https://doi.org/10.1086/675603.

167. Lee K, Yong D, Jeong SH, Chong Y. 2011. Multidrug-resistant Acineto-bacter spp.: increasingly problematic nosocomial pathogens. YonseiMed J 52:879 – 891. https://doi.org/10.3349/ymj.2011.52.6.879.

168. Song W, Lee J, Kim TK, Park MJ, Kim HS, Kim JS. 2013. ModifiedCHROMagar Acinetobacter medium for direct detection of multidrug-resistant Acinetobacter strains in nasal and rectal swab samples. AnnLab Med 33:193–195. https://doi.org/10.3343/alm.2013.33.3.193.

169. Girlich D, Nordmann P. 2015. CHROMagar Acinetobacter medium fordetection of carbapenemase-producing Acinetobacter spp. strains fromspiked stools. Diagn Microbiol Infect Dis 83:234 –236. https://doi.org/10.1016/j.diagmicrobio.2015.06.023.

170. Higgins PG, Nowak J, Devigne L, Seifert H. 2014. Abstr 24th Eur Congr ClinMicrobiol Infect Dis, abstr eP322. Evaluation of chromID® CARBA andchromID® OXA-48 media for the detection of carbapenemase-producingAcinetobacter spp. https://www.escmid.org/escmid_publications/escmid_elibrary/material/?mid�15919.

171. Zarakolu P, Day KM, Lanyon CV, Cummings SP, Perry JD. 2015. Abstr25th Eur Congr Clin Microbiol Infect Dis, abstr EVO528. An evaluation ofchromID® CARBA for the isolation of carbapenem-resistant Acinetobac-ter baumannii. https://www.escmid.org/escmid_publications/escmid_elibrary/material/?mid�26034.

172. van Belkum A, Chatellier S, Girard V, Pincus D, Deol P, Dunne WM, Jr.2015. Progress in proteomics for clinical microbiology: MALDI-TOF MSfor microbial species identification and more. Expert Rev Proteomics12:595– 605. https://doi.org/10.1586/14789450.2015.1091731.

173. Hrabák J, Studentová V, Walková R, Zemlicková H, Jakubu V, Chudáck-ová E, Gniadkowski M, Pfeifer Y, Perry JD, Wilkinson K, Bergerová T.2012. Detection of NDM-1, VIM-1, KPC, OXA-48, and OXA-162 carbap-enemases by matrix-assisted laser desorption ionization–time of flightmass spectrometry. J Clin Microbiol 50:2441–2443. https://doi.org/10.1128/JCM.01002-12.

174. Li B, Guo T, Qu F, Li B, Wang H, Sun Z, Li X, Gao Z, Bao C, Zhang C, LiX, Mao Y. 2014. Matrix-assisted laser desorption ionization: time offlight mass spectrometry-identified models for detection of ESBL-producing bacterial strains. Med Sci Monit Basic Res 20:176 –183.https://doi.org/10.12659/MSMBR.892670.

175. Binghuai L, Yanli S, Shuchen Z, Fengxia Z, Dong L, Yanchao C. 2014. Useof MALDI-TOF mass spectrometry for rapid identification of group BStreptococcus on chromID Strepto B agar. Int J Infect Dis 27:44 – 48.https://doi.org/10.1016/j.ijid.2014.06.023.

176. Charretier Y, Dauwalder O, Franceschi C, Degout-Charmette E, Zam-bardi G, Cecchini T, Bardet C, Lacoux X, Dufour P, Veron L, Rostaing H,Lanet V, Fortin T, Beaulieu C, Perrot N, Dechaume D, Pons S, Girard V,Salvador A, Durand G, Mallard F, Theretz A, Broyer P, Chatellier S,Gervasi G, Van Nuenen M, Roitsch CA, Van Belkum A, Lemoine J,Vandenesch F, Charrier JP. 2015. Rapid bacterial identification, resis-tance, virulence and type profiling using selected reaction monitor-ing mass spectrometry. Sci Rep 5:13944. https://doi.org/10.1038/srep13944.

177. Croxatto A, Dijkstra K, Prod’hom G, Greub G. 2015. Comparison ofinoculation with the InoqulA and WASP automated systems with man-ual inoculation. J Clin Microbiol 53:2298 –2307. https://doi.org/10.1128/JCM.03076-14.

178. Faron ML, Buchan BW, Coon C, Liebregts T, van Bree A, Jansz AR, SoucyG, Korver J, Ledeboer NA. 2016. Automatic digital analysis of chromo-genic media for vancomycin resistant enterococci screens using theCopan WASPLab™. J Clin Microbiol 54:2464 –2469. https://doi.org/10.1128/JCM.01040-16.

179. Faron ML, Buchan BW, Vismara C, Lacchini C, Bielli A, Gesu G, LiebregtsT, van Bree A, Jansz A, Soucy G, Korver J, Ledeboer NA. 2016. Auto-mated scoring of chromogenic media for detection of methicillin-resistant Staphylococcus aureus by use of WASPLab image analysissoftware. J Clin Microbiol 54:620 – 624. https://doi.org/10.1128/JCM.02778-15.

180. Kirn TJ. 2016. Automatic digital plate reading for surveillance cultures.J Clin Microbiol 54:2424 –2426. https://doi.org/10.1128/JCM.01279-16.

181. Pallis A, Jazayeri J, Ward P, Dimovski K, Svobodova S. 2013. Rapiddetection of Clostridium difficile toxins from stool samples using real-time multiplex PCR. J Med Microbiol 62:1350 –1356. https://doi.org/10.1099/jmm.0.058339-0.

182. Putsathit P, Morgan J, Bradford D, Engelhardt N, Riley TV. 2015. Eval-uation of the BD Max Cdiff assay for the detection of toxigenic Clos-tridium difficile in human stool specimens. Pathology 47:165–168.https://doi.org/10.1097/PAT.0000000000000214.

183. Seo JY, Kim PW, Lee JH, Song JH, Peck KR, Chung DR, Kang CI, Ki CS, LeeNY. 2011. Evaluation of PCR-based screening for vancomycin-resistantenterococci compared with a chromogenic agar-based culture method.J Med Microbiol 60:945–949. https://doi.org/10.1099/jmm.0.029777-0.

184. Bae MH, Kim J, Sung H, Jeong YS, Kim MN. 2013. Evaluation of iNtRONVRE vanA/vanB real-time PCR for follow-up surveillance of VRE-infectedor colonized patients. Diagn Microbiol Infect Dis 77:292–295. https://doi.org/10.1016/j.diagmicrobio.2013.08.006.

185. Devrim F, Gülfidan G, Gözmen S, Demirag B, Oymak Y, Yaman Y, OruçY, Yasar N, Apa H, Bayram N, Vergin C, Devrim I. 2015. Comparison ofthe BD GeneOhm VanR assay and a chromogenic agar-based culturemethod in screening for vancomycin-resistant enterococci in rectalspecimens of pediatric hematology-oncology patients. Turk J Pediatr57:161–166.

186. Huh HJ, Jang MA, Seo JY, Kim JY, Ki CS, Kim JW, Lee NY. 2015.Evaluation of the iNtRON VRE vanA/vanB real-time PCR assay for de-tection of vancomycin-resistant enterococci. Ann Lab Med 35:76 – 81.https://doi.org/10.3343/alm.2015.35.1.76.

187. El Aila NA, Tency I, Claeys G, Verstraelen H, Deschaght P, Decat E, Lopesdos Santos Santiago G, Cools P, Temmerman M, Vaneechoutte M. 2011.Comparison of culture with two different qPCR assays for detection ofrectovaginal carriage of Streptococcus agalactiae (group B streptococci)in pregnant women. Res Microbiol 162:499 –505. https://doi.org/10.1016/j.resmic.2011.04.001.

188. Grandjean F, Goffinet P, Hougardy N. 2007. Detection of colonizationby Streptococcus agalactiae: prospective study comparing real-timegene amplification with a new chromogenic medium Strepto B ID.Pathol Biol (Paris) 55:407– 411. https://doi.org/10.1016/j.patbio.2007.07.008.

189. de Tejada BM, Pfister RE, Renzi G, François P, Irion O, Boulvain M,Schrenzel J. 2011. Intrapartum group B streptococcus detection byrapid polymerase chain reaction assay for the prevention of neonatalsepsis. Clin Microbiol Infect 17:1786 –1791. https://doi.org/10.1111/j.1469-0691.2010.03378.x.

190. Mueller M, Henle A, Droz S, Kind AB, Rohner S, Baumann M, Surbek D.2014. Intrapartum detection of group B streptococci colonization byrapid PCR-test on labor ward. Eur J Obstet Gynecol Reprod Biol 176:137–141. https://doi.org/10.1016/j.ejogrb.2014.02.039.

191. de Boer RF, Ott A, Kesztyüs B, Kooistra-Smid AM. 2010. Improveddetection of five major gastrointestinal pathogens by use of a molec-ular screening approach. J Clin Microbiol 48:4140 – 4146. https://doi.org/10.1128/JCM.01124-10.

192. Buss SN, Leber A, Chapin K, Fey PD, Bankowski MJ, Jones MK, Ro-gatcheva M, Kanack KJ, Bourzac KM. 2015. Multicenter evaluation of theBioFire FilmArray gastrointestinal panel for etiologic diagnosis of infec-tious gastroenteritis. J Clin Microbiol 53:915–925. https://doi.org/10.1128/JCM.02674-14.

193. Zhang H, Morrison S, Tang YW. 2015. Multiplex polymerase chainreaction tests for detection of pathogens associated with gastroenteri-tis. Clin Lab Med 5:461– 486.

194. Shea S, Kubota KA, Maguire H, Gladbach S, Woron A, Atkinson-Dunn R,Couturier MR, Miller MB. 19 October 2016. Clinical microbiology labo-ratories’ adoption of culture independent diagnostic tests are a threat




http://cmr.asm

.org/D

ownloaded from

https://doi.org/10.1099/jmm.0.000244

https://doi.org/10.1128/JCM.06477-11





https://doi.org/10.1086/675603

https://doi.org/10.3349/ymj.2011.52.6.879

https://doi.org/10.3343/alm.2013.33.3.193







https://doi.org/10.1586/14789450.2015.1091731

https://doi.org/10.1128/JCM.01002-12

https://doi.org/10.1128/JCM.01002-12

https://doi.org/10.12659/MSMBR.892670

https://doi.org/10.1016/j.ijid.2014.06.023

https://doi.org/10.1038/srep13944

https://doi.org/10.1038/srep13944

https://doi.org/10.1128/JCM.03076-14

https://doi.org/10.1128/JCM.03076-14

https://doi.org/10.1128/JCM.01040-16

https://doi.org/10.1128/JCM.01040-16

https://doi.org/10.1128/JCM.02778-15

https://doi.org/10.1128/JCM.02778-15

https://doi.org/10.1128/JCM.01279-16

https://doi.org/10.1099/jmm.0.058339-0

https://doi.org/10.1099/jmm.0.058339-0

https://doi.org/10.1097/PAT.0000000000000214

https://doi.org/10.1099/jmm.0.029777-0



https://doi.org/10.3343/alm.2015.35.1.76

https://doi.org/10.1016/j.resmic.2011.04.001

https://doi.org/10.1016/j.resmic.2011.04.001

https://doi.org/10.1016/j.patbio.2007.07.008

https://doi.org/10.1016/j.patbio.2007.07.008

https://doi.org/10.1111/j.1469-0691.2010.03378.x

https://doi.org/10.1111/j.1469-0691.2010.03378.x

https://doi.org/10.1016/j.ejogrb.2014.02.039

https://doi.org/10.1128/JCM.01124-10

https://doi.org/10.1128/JCM.01124-10

https://doi.org/10.1128/JCM.02674-14

https://doi.org/10.1128/JCM.02674-14

http://cmr.asm.org

http://cmr.asm.org/

to food-borne disease surveillance in the United States. J Clin Microbiolhttps://doi.org/10.1128/JCM.01624-16.

195. Lee S, Park YJ, Park KG, Jekarl DW, Chae H, Yoo JK, Seo SW, Choi JE, LimJH, Heo SM, Seo JH. 2013. Comparative evaluation of three chromo-genic media combined with broth enrichment and the real-time PCR-based Xpert MRSA assay for screening of methicillin-resistant Staphy-lococcus aureus in nasal swabs. Ann Lab Med 33:255–260. https://doi.org/10.3343/alm.2013.33.4.255.

196. Patel PA, Robicsek A, Grayes A, Schora DM, Peterson KE, Wright MO,Peterson LR. 2015. Evaluation of multiple real-time PCR tests on nasalsamples in a large MRSA surveillance program. Am J Clin Pathol143:652– 658. https://doi.org/10.1309/AJCPMDY32ZTDXPFC.

197. Durmaz G, Sanci O, Oz Y, Guven K, Kiremitci A, Aksit F. 2016. Methicillin-resistant S. aureus colonization in intensive care unit patients: earlyidentification and molecular typing. J Infect Dev Ctries 10:465– 471.https://doi.org/10.3855/jidc.6575.

198. Danial J, Noel M, Templeton KE, Cameron F, Mathewson F, Smith M,Cepeda JA. 2011. Real-time evaluation of an optimized real-time PCRassay versus Brilliance chromogenic MRSA agar for the detection ofmeticillin-resistant Staphylococcus aureus from clinical specimens. JMed Microbiol 60:323–328. https://doi.org/10.1099/jmm.0.025288-0.

199. Yam WC, Siu GK, Ho PL, Ng TK, Que TL, Yip KT, Fok CP, Chen JH, ChengVC, Yuen KY. 2013. Evaluation of the LightCycler methicillin-resistantStaphylococcus aureus (MRSA) advanced test for detection of MRSAnasal colonization. J Clin Microbiol 51:2869 –2874. https://doi.org/10.1128/JCM.00488-13.

200. Roisin S, Laurent C, Nonhoff C, Deplano A, Hallin M, Byl B, Struelens MJ,Denis O. 2012. Positive predictive value of the Xpert MRSA assaydiagnostic for universal patient screening at hospital admission: influ-ence of the local ecology. Eur J Clin Microbiol Infect Dis 31:873– 880.https://doi.org/10.1007/s10096-011-1387-7.

201. Aydiner A, Lüsebrink J, Schildgen V, Winterfeld I, Knüver O, Schwarz K,Messler S, Schildgen O, Mattner F. 2012. Comparison of two commer-cial PCR methods for methicillin-resistant Staphylococcus aureus (MRSA)screening in a tertiary care hospital. PLoS One 7:e43935. https://doi.org/10.1371/journal.pone.0043935.

202. Roisin S, Laurent C, Denis O, Dramaix M, Nonhoff C, Hallin M, Byl B,Struelens MJ. 2014. Impact of rapid molecular screening at hospitaladmission on nosocomial transmission of methicillin-resistant Staphy-lococcus aureus: cluster randomised trial. PLoS One 9:e96310. https://doi.org/10.1371/journal.pone.0096310.

203. Polisena J, Chen S, Cimon K, McGill S, Forward K, Gardam M. 2011.Clinical effectiveness of rapid tests for methicillin resistant Staphylococ-cus aureus (MRSA) in hospitalized patients: a systematic review. BMCInfect Dis 11:336. https://doi.org/10.1186/1471-2334-11-336.

204. Derde LP, Cooper BS, Goossens H, Malhotra-Kumar S, Willems RJ,Gniadkowski M, Hryniewicz W, Empel J, Dautzenberg MJ, Annane D,Aragão I, Chalfine A, Dumpis U, Esteves F, Giamarellou H, Muzlovic I,Nardi G, Petrikkos GL, Tomic V, Martí AT, Stammet P, Brun-Buisson C,Bonten MJ, MOSAR WP3 Study Team. 2014. Interventions to reducecolonisation and transmission of antimicrobial-resistant bacteria inintensive care units: an interrupted time series study and cluster ran-

domised trial. Lancet Infect Dis 14:31–39. https://doi.org/10.1016/S1473-3099(13)70295-0.

205. Huang TD, Bogaerts P, Ghilani E, Heinrichs A, Gavage P, Roisin S,Willems E, Verbruggen AM, Francart H, Denis O, Senterre JM, Glupc-zynski Y. 2015. Multicentre evaluation of the Check-Direct CPE® assayfor direct screening of carbapenemase-producing Enterobacteriaceaefrom rectal swabs. J Antimicrob Chemother 70:1669 –1673. https://doi.org/10.1093/jac/dkv009.

206. Antonelli A, Di Palo DM, Galano A, Becciani S, Montagnani C, Pecile P,Galli L, Rossolini GM. 2015. Intestinal carriage of Shewanella xiamenensissimulating carriage of OXA-48-producing Enterobacteriaceae. DiagnMicrobiol Infect Dis 82:1–3. https://doi.org/10.1016/j.diagmicrobio.2015.02.008.

207. Brady AC, Lewis JS, II, Pfeiffer CD. 2016. Rapid detection of blaOXA incarbapenem-susceptible Acinetobacter radioresistens bacteremia lead-ing to unnecessary antimicrobial administration. Diagn Microbiol InfectDis 85:488 – 489. https://doi.org/10.1016/j.diagmicrobio.2016.04.025.

208. Otter JA, Dyakova E, Bisnauthsing KN, Querol-Rubiera A, Patel A, Aha-nonu C, Tosas Auguet O, Edgeworth JD, Goldenberg SD. 2016. Univer-sal hospital admission screening for carbapenemase-producing organ-isms in a low-prevalence setting. J Antimicrob Chemother 71:3556 –3561. https://doi.org/10.1093/jac/dkw309.

209. Luk S, To WK, Ng TK, Hui WT, Lee WK, Lau F, Ching AM. 2014. Acost-effective approach for detection of toxigenic Clostridium difficile:toxigenic culture using chromID Clostridium difficile agar. J Clin Micro-biol 52:671– 673. https://doi.org/10.1128/JCM.03113-13.

210. Olling A, Leidinger H, Hoffmann R. 2016. Comparison of enzyme im-munoassays and rapid diagnostic tests for Clostridium difficile gluta-mate dehydrogenase and toxin A � B to toxinogenic culture on ahighly selective chromogenic medium. Eur J Clin Microbiol Infect Dis35:1655–1659. https://doi.org/10.1007/s10096-016-2706-9.

211. Savini V, Marrollo R, Serio A, Paparella A, Argentieri AV, D’Antonio M,Coclite E, Fusilli P, Fazii P. 2014. Liofilchem(®) O.A. Listeria agar anddirect CAMP test provided sooner Listeria monocytogenes identificationfrom neonatal bacteremia. Int J Clin Exp Pathol 7:1172–1175.

212. Tierney D, Copsey SD, Morris T, Perry JD. 2016. A new chromogenicmedium for isolation of Bacteroides fragilis suitable for screening forstrains with antimicrobial resistance. Anaerobe 39:168 –172. https://doi.org/10.1016/j.anaerobe.2016.04.003.

213. Bernasconi OJ, Kuenzli E, Pires J, Tinguely R, Carattoli A, Hatz C,Perreten V, Endimiani A. 2016. Travelers can import colistin-resistantEnterobacteriaceae, including those possessing the plasmid-mediatedmcr-1 gene. Antimicrob Agents Chemother 60:5080 –5084. https://doi.org/10.1128/AAC.00731-16.

214. Ellington MJ, Ekelund O, Aarestrup FM, Canton R, Doumith M, Giske C,Grundman H, Hasman H, Holden M, Hopkins KL, Iredell J, Kahlmeter G,Köser CU, MacGowan A, Mevius D, Mulvey M, Naas T, Peto T, Rolain JM,Samuelsen Ø, Woodford N. 23 November 2016. The role of wholegenome sequencing (WGS) in antimicrobial susceptibility testing ofbacteria: report from the EUCAST subcommittee. Clin Microbiol Infecthttps://doi.org/10.1016/j.cmi.2016.11.012.

John D. Perry, Ph.D., D.Sc., is a Clinical Scien-tist at the Freeman Hospital in Newcastle uponTyne, UK. His graduate and postgraduate train-ing were at Northumbria University, where heserves as a Visiting Professor. Dr. Perry has astrong interest in the laboratory aspects of anti-microbial chemotherapy and serves as a senioreditor for the Journal of Antimicrobial Chemo-therapy. He also has a longstanding interest inmicrobial biochemistry and the design andevaluation of new culture media and other di-agnostic methods through the application of enzyme substrates and novelgrowth inhibitors.




http://cmr.asm

.org/D

ownloaded from

https://doi.org/10.1128/JCM.01624-16

https://doi.org/10.3343/alm.2013.33.4.255

https://doi.org/10.3343/alm.2013.33.4.255

https://doi.org/10.1309/AJCPMDY32ZTDXPFC

https://doi.org/10.3855/jidc.6575

https://doi.org/10.1099/jmm.0.025288-0

https://doi.org/10.1128/JCM.00488-13

https://doi.org/10.1128/JCM.00488-13

https://doi.org/10.1007/s10096-011-1387-7

https://doi.org/10.1371/journal.pone.0043935




https://doi.org/10.1186/1471-2334-11-336

https://doi.org/10.1016/S1473-3099(13)70295-0

https://doi.org/10.1016/S1473-3099(13)70295-0

https://doi.org/10.1093/jac/dkv009

https://doi.org/10.1093/jac/dkv009




https://doi.org/10.1093/jac/dkw309

https://doi.org/10.1128/JCM.03113-13

https://doi.org/10.1007/s10096-016-2706-9

https://doi.org/10.1016/j.anaerobe.2016.04.003

https://doi.org/10.1016/j.anaerobe.2016.04.003

https://doi.org/10.1128/AAC.00731-16

https://doi.org/10.1128/AAC.00731-16


http://cmr.asm.org

http://cmr.asm.org/

Correction for Perry, “A Decade ofDevelopment of Chromogenic CultureMedia for Clinical Microbiology in an Eraof Molecular Diagnostics”

John D. PerryMicrobiology Department, Freeman Hospital, Newcastle upon Tyne, UK

Volume 30, no. 2, p. 449 – 479, 2017, https://doi.org/10.1128/CMR.00097-16. Page457, line 1: “a simple disk test for pyroglutamyl aminopeptidase” should read “a simpledisk test for L-proline aminopeptidase.”

Published 13 September 2017

Citation Perry JD. 2017. Correction for Perry,“A decade of development of chromogenicculture media for clinical microbiology in anera of molecular diagnostics.” Clin Microbiol Rev30:vii. https://doi.org/10.1128/CMR.00073-17.

© Crown copyright 2017. The government ofAustralia, Canada, or the UK (“the Crown”) ownsthe copyright interests of authors who aregovernment employees. The Crown Copyrightis not transferable.

AUTHOR CORRECTION

crossm

October 2017 Volume 30 Issue 4 cmr.asm.org viiClinical Microbiology Reviews

https://doi.org/10.1128/CMR.00097-16

https://doi.org/10.1128/CMR.00073-17

https://doi.org/10.1128/ASMCrownCopyrightv2

http://crossmark.crossref.org/dialog/?doi=10.1128/CMR.00073-17&domain=pdf&date_stamp=2017-9-13

http://cmr.asm.org

Documents

A Decade of Development of Chromogenic Culture Media for ...CULTURE USING CHROMOGENIC MEDIA VERSUS MOLECULAR DIAGNOSTIC METHODS.....469 CONCLUSIONS ... remain undetected as mixtures