Journal of Feline Medicine and Surgery (2010) 12, 509e511doi:10.1016/j.jfms.2010.01.008

SHORT COMMUNICATIONHelicobacter species detection and histopathologicalchanges in stray cats from Niteroi, Brazil

Isabela C Araujo DVM, Simone B Mota DVM, PhD, Maria Helena C de Aquino DVM, PhD*,Ana Maria R Ferreira DVM, PhD

Department of Clinical andSurgery, Faculty of VeterinaryMedicine, Fluminense FederalUniversity, Rua Vital Brazil Filho,n 64, Niteroi, Rio de Janeiro, CEP24230 340, Brazil

*Corresponding author. Tel/Fax: þ5maryhel@uol.com.br

1098-612X/10/060509+03 $36.00/0

Tightly coiled bacteria are common inhabitants of the gastric mucosae of catsand there is considerable debate whether feline helicobacters are commensal orpathogenic organisms. To determine the prevalence of Helicobacter species andgastric histopathological findings, gastric mucosa samples of 56 stray cats werecollected from cardia, fundus, body, antrum and pylorus at necropsy. Thesamples were examined by urease test, cytology, histopathology and culture.Helicobacter species were detected in 53 cats (94.6%) by at least one detectionmethod. Urease test results were positive in gastric samples from 50 (89.3%) cats.Cytological and histological evaluations revealed Helicobacter species in 52(92.8%) and 50 (89.2%) cats, respectively. Helicobacter species organisms were notcultured from any cat. Regardless of the presence of gastric bacteria, most of thecats had mild to moderate gastritis. These data reveal a high prevalence ofHelicobacter species in stray cats from Niteroi, Brazil.

Date accepted: 21 January 2010 � 2010 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.

In early reports, large and tightly coiled organismswere considered to be innocuous commensal or-ganisms in cats, but latter studies documented

the association of these organisms with chronic gastri-tis and gastric lymphoma.1,2 These organisms includemainly Helicobacter felis, Helicobacter bizzozeronii,Helicobacter salomonis and a Helicobacter-like organism(HLO).3 In humans, they are a rare cause of gastric pa-thology and represent a mixture of species for whicha zoonotic origin is suspected.1,3 The global preva-lence of Helicobacter species infection in cats variesfrom 40% to 100%,3,4 and geographic variations maypartially account for these differences. Consideringthe lack of data from cats in Brazil, the aims of thisstudy were to investigate the prevalence of Helico-bacter species in cats, if these organisms were cultura-ble, if there were differences in bacterial distributionamong the gastric regions and if naturally occurringgastric bacteria were associated with gastritis in cats.

Samples were collected from the stomachs of 56stray cats (25 male and 31 female and ages rangingfrom 2 months to 13 years) scheduled to be eutha-nased by the Municipal Zoonosis Control Center of

5 21 26299534. E-mail:

� 2010 ISFM an

Niteroi City. The samples were collected immediatelyafter euthanasia. At necropsy, stomachs were re-moved, opened along the greater curvature, and ex-amined. Samples from cardia, fundus, body, antrumand pylorus were removed for urease testing, cytol-ogy, histopathology and culture. For the urease test,gastric mucosal specimens were incubated in tubescontaining urea broth (10%) and were scored positiveif the phenol red indicator turned red within 24 h. Thetubes were monitored hourly for 8 h and evaluated fora final time at 24 h to estimate the density of colonisa-tion by Helicobacter species in the different regions ofthe stomach, by the time the phenol red indicatorturned red.4 Samples for culture were minced in salineand a drop of the material was placed onto Brucellaspecies agar (Difco) containing 7% sheep blood, van-comycin (2.5 mg/ml), amphotericin B (1.25 mg/ml),cefsulodin (1.25 mg/ml) and trimethoprim (1.25mg/ml) (Oxoid SR 147). The plates were incubated inan anaerobic jar with a microaerophilic gas generatingkit (Oxoid BR 056) at 37�C for 7 days. For cytologicaland histopathological examinations, carbolfuchsin-stained impression smears were viewed in differentfields under light microscopy and formalin-fixed gas-tric mucosal specimens were stained with haematoxy-lineeosin (HE) and with WarthineStarry (WS) stain,

d AAFP. Published by Elsevier Ltd. All rights reserved.

Table 1. Urease test results (number and %) as a function of the time interval and gastric regions of the56 investigated cats.

Gastric regions Positive samples Negative samples

Within 2 h Within 2 and 8 h Within 8 and 24 h By 24 h

Cardia 30 (53.6) 19 (33.9) 1 (1.8) 6 (10.7)Fundus 42 (75.0) 7 (12.5) 1 (1.8) 6 (10.7)Body 41 (73.2) 9 (16.1) e 6 (10.7)Antrum 39 (69.6) 9 (16.1) 2 (3.6) 6 (10.7)Pylorus 28 (50.0) 12 (21.4) 5 (8.9) 11 (19.7)

510 IC Araujo et al

respectively. Gastritis was defined as follows: (�) nogastritis, no lymphoid aggregates, <5 leukocytes perhigh-power field, and normal mucosal epithelium;(þ) mild gastritis, fewer than two lymphoid aggre-gates per low-power field and/or 5e25 leukocytesper high-power field and normal mucosal epithelium;(þþ) moderate gastritis, more than two lymphoid ag-gregates per low-power field, and 26e50 or mores leu-kocytes per high-power field, and/or mild gastricepithelial changes; (þþþ) severe gastritis, greaterthan five lymphoid aggregates and/or >50 leukocytesper high-power field and marked epithelial changes.4

The c2 analysis was performed on the data to investi-gate the association between Helicobacter species pres-ence and gastric regions and the detection methods.Results were considered statistically significant atP< 0.05.5

Fifteen cats (26.8%) had gross changes of the gastricmucosa including hyperaemia (n¼ 13), multiple pete-chiaes in the body and fundus (n¼ 3) and ulcers (1 cmin diameter) in the antrum and fundus (n¼ 2). Theurease test was positive for samples from 50/56 cats(89.3%). All the gastric regions from 44 cats (78.5%)were urease positive, while all the gastric regionsfrom six cats (10.7%) were urease negative. Most offundus (75%), body (73.2%) and antrum (69.6%) sam-ples became positive in less than 2 h, while 19.7% ofthe pylorus samples were negative by 24 h (Table 1).The area of gastric mucosa most highly colonised byHelicobacter species has variably been reported as thefundus or corpus.2,6 However, in this study therewas no significant difference in colonisation densitybetween the gastric regions evaluated (P> 0.05), asalso previously reported.4,6,8

Table 2. Distribution of Helicobacter species positivdetection method and gastric regions of the 56 inves

Detection methods

Cardia Fundus

Urease test 50 (89.3) 50 (89.3)Cytology 51 (91.1) 51 (91.1)Histology 48 (85.7) 49 (87.5)

Cytological and histological evaluation revealedspiral bacteria in 52 (92.8%) and 50 (89.3%) cats, re-spectively (Table 2). Four cats had negative resultsfor both methods. The organisms were easily identi-fied on slides stained with WS and carbolfuchsin,but visualisation was not so easy when HE wasused. The Helicobacter species organisms were locatedin mucus, gastric pits and glands and within the cyto-plasm of parietal cells. The gastric colonisation ap-peared to be heaviest in the gastric pits and in thelumen of the gastric glands. Helicobacter species werenot cultured from any cat. The urease test, cytologyand histopathology were equally efficient in detectingHelicobacter species (P> 0.05).

The gross observations of gastric ulcers were con-firmed histologically by the presence of haemorrhageand severe epithelial changes including necrosis andgastric erosions. Histological findings in the presentstudy ranged from ‘normal’ gastric mucosa to severegastritis, regardless of the presence of gastric bacteria,and were similar to previous studies.7,8 Most animals(n¼ 42) had mild gastritis and the remaining animalshad moderate (n¼ 9) and severe gastritis (n¼ 3). Twoanimals were free of lesions and of spiral bacteria bycytology and histopathology. Focal or multifocal lym-phoplasmacytic infiltrates were observed in 54 cats(96.4%), lymphoid follicles hyperplasia in 32 cats(57%) and fibrosis in 29 cats (51.8%). Polymorphonu-clear leukocytes were rarely present and detectedmainly in fundus. Histological changes in the laminapropria including mild mononuclear inflammatory in-filtration, the presence of lymphoid follicles, fibrosisand glandular degeneration are commonly reportedin cats with Helicobacter species infection. However,

e samples (number and %) as a function of thetigated cats.

Gastric region

Body Antrum Pylorus

50 (89.3) 50 (89.3) 45 (80.3)50 (89.3) 52 (92.8) 42 (75.0)50 (89.3) 50 (89.3) 46 (82.1)

511Helicobacter species in stray Brazilian cats

in this study no correlation was found between gastri-tis and Helicobacter species infection. Other investiga-tions also have failed to detect any correlationbetween gastritis and Helicobacter species infection,as both infected and uninfected cats showed thesame type and quantity of lesions.2,6,9,10

The results of this study agree other studies, whichfrequently suggested the presence of Helicobacter spe-cies in cats, with a prevalence higher than 40%.3,4 Inour study, 53/56 cats (94.6%) had gastric spiral bacte-ria identified by at least one detection method. As theattempts to culture the organisms were unsuccessful,they were classified as Helicobacter species based onmorphological type (large and tightly coiled organ-isms) which normally in cats, include mainly Helico-bacter heilmannii, an uncultured Helicobacter species,H felis, H bizzozeronii and H salomonis.10,11 Anotherclosely related species isolated from a cat has beenrecently described as Helicobacter baculiformis.11

Our results show a high percentage of stray catswith gastric lesions harboring Helicobacter speciesand suggest that cats are frequently colonised. How-ever, no obvious relation between the extent of histo-pathological changes, colonisation density and thedistribution of Helicobacter species among the gastricregions was established.

References1. Bridgeford EC, Marini RP, Feng Y, Parry NMA, Rickman

B, Fox FG. Gastric Helicobacter species as a cause of feline

gastric lymphoma: a viable hypothesis. Vet ImmunolImmunopathol 2008; 123: 106e13.

2. Simpson K, Neiger R, DeNovo R, Sherding R. The rela-tionship of Helicobacter spp infection to gastric diseasein dogs and cats. J Vet Intern Med 2000; 14: 223e7.

3. Van den Bulck K, Decostere A, Baele M, et al. Identifica-tion of non-Helicobacter pylori spiral organisms in gastricsamples from humans, dogs and cats. J Clin Microbiol2005; 43: 2256e60.

4. Erginsoy SD, Sozmen M. Gastric Helicobacter-like organ-isms in stray cats. Acta Vet Brno 2006; 75: 91e8.

5. Thrusfield MV. Veterinary epidemiology. 2nd edn.Oxford: Blackwell Publishing, 2003.

6. Takemura LS, Camargo PL, Alfieri AA, BracarensePFRL. Helicobacter spp in cats: association between in-fecting species and epithelial proliferation within thegastric lamina propria. J Com Pathol 2009; 141: 127e34.

7. Yamasaki K, Suematsu H, Takahashi T. Comparison ofgastric lesions in dogs and cats with and without gastricspiral organisms. J Am Med Assoc 1998; 212: 529e33.

8. Strauss-Ayali D, Simpson KW, Schein AH, et al.Serological discrimination of dogs infected with gastricHelicobacter spp and uninfected dogs. J Clin Microbiol1999; 37: 1280e7.

9. Lecoindre P, Chevallier M, Peyrol S, Boude M, FerreroRL, Labigne A. Gastric helicobacters in cats. J FelineMed Surg 2000; 2: 19e27.

10. Neiger R, Simpson KW. Helicobacter infection in dogsand cats: facts and fiction. J Vet Intern Med 2000; 14:125e33.

11. Baele M, Pasmans F, Flahou B, Chiers K, Ducatelle R,Haesebrouck F. Non-Helicobacter pylori helicobactersdetected in the stomach of humans comprise severalnaturally occurring Helicobacter species in animals.FEMS Immunol Med Microbiol 2009; 55: 306e13.

Available online at www.sciencedirect.com