Upper Respiratory Tract Infections - Dr.Valizadehiacld.ir/DL/modavan/bacteriology/upperrespiratorytract...Ph itiPharyngitis ¾Viruses are the most common cause of pharyngitis in both

Upper RespiratoryUpper RespiratoryUpper Respiratory Upper Respiratory Tract InfectionsTract InfectionsTract InfectionsTract Infections

Babak Valizadeh,[email protected][email protected]

1390 / 11 / 142012.02.03

Upper Respiratory Tract InfectionsUpper Respiratory Tract InfectionsUppe espi ato y act nfectionsUppe espi ato y act nfections

PharyngitisPharyngitisPharyngitisPharyngitisSinusitisSinusitisSinusitisSinusitisOcular InfectionsOcular InfectionsOcular InfectionsOcular InfectionsOtitisOtitis

Nasopharyngeal and Oropharyngeal Organisms in the Normal Hostin the Normal Host

PharyngitisPharyngitis& tonsillitis

Ph itiPharyngitis

Viruses are the most common cause of pharyngitis in both adult and pediatric populations

Primary infection with herpes simplex virus may bePrimary infection with herpes simplex virus may be indistinguishable from infections due to other viruses or GAS

Patients with Epstein-Barr virus (EBV) infection may present with an exudative tonsillitis or pharyngitis

E t iE t i B i (EBV) i f tiB i (EBV) i f tiEpsteinEpstein--Barr virus (EBV) infectionBarr virus (EBV) infection

Ad iAdenoviruses

Adenoviruses produce an acuteAdenoviruses produce an acute pharyngitis that resembles streptococcal pharyngitispharyngitis

C j ti iti ft i t i dditi /Conjunctivitis often is present in addition/ Pharyngoconjunctival fever

Antibiotics Often Overprescribed for Viral R i I f iRespiratory Infections

Infect Contr Hosp Epidemiol. 20102010;31:11

In Pennsylvania ; 196 had a viral assay positive for influen a A or B parainfluen a adenovirus orinfluenza A or B, parainfluenza, adenovirus, or respiratory syncytial virus

Of h 131 (69%) i i d ibi iOf these, 131 (69%) patients received antibiotics, including 125 (64%)who continued to receive antibiotics after diagnosis of viral RTI

Clostridium difficile infection developed in 8 patients (6%) who continued on antibiotics

Ph itiPharyngitis

Normal pharyngeal flora, such as y g fStaphylococcus aureusStaphylococcus aureus, , Streptococcus Streptococcus pneumoniaepneumoniae, and , and Haemophilus influenzaeHaemophilus influenzae,,should not be reported from routine throatshould not be reported from routine throat cultures

To do so encourages inappropriateantimicrobial therapypy

Group A StreptococciGroup A Streptococci

GASGAS

Ph itiPharyngitis

Presentation of upper respiratory tract infection i h h d hi h i i fwith cough and rhinorrhea is suggestive of a

nonstreptococcal etiology

In one study of pediatric patients :36% of those presenting with cough &45% of pediatric patients presenting with coryzasymptoms had throat cultures that were positive for group A streptococci (GAS)for group A streptococci (GAS)

Th t ltThroat culture

Throat culture remains the gold standard for the diagnosis of streptococcalfor the diagnosis of streptococcal pharyngitis

Sensitivity : 90% & Specificity : 99 %

G A St t i (GAS)Group A Streptococci (GAS)

Rapid antigen detection test in 10-30 minutes. (1980s)

> 40 commercial Kit (POCT)

Specificity > 95 % & sensitivity 80-90 %

Negative Result Should be cultured in Children & Adolescence

Group A Streptococcal Pharyngitisp p y gTherapy

For almost 5 decades, penicillin hasFor almost 5 decades, penicillin has been the drug of choice

Over the past 40 years have reported penicillin bacteriologic failure ratespenicillin bacteriologic failure rates ranging from 10 to 30 percent and clinical failure rates ranging from 5 to 15 percentfailure rates ranging from 5 to 15 percent

Group A Streptococcal Pharyngitisp p y gTreatment Failure and ReinfectionTreatment Failure and Reinfection

Group A beta hemolyticGroup A beta-hemolytic streptococci persist forstreptococci persist for up to 15 days on p yunrinsed toothbrushes


Close Contacts :DuringClose Contacts :During epidemics, 50 percent of the siblings and 20 percent of the parents of infected children p f fdevelop streptococcal pharyngitis


BetaBeta--lactamaselactamase––producing copathogensproducing copathogens

A i illi l lAmoxicillin-clavulanateis often used to treat recurrent streptococcal pharyngitis

S i C ll tiSpecimen Collection

It is important to vigorouslyIt is important to vigorouslyswab the tonsillar areas and the posterior pharynx


Th t lt /Throat culture / 2006

Diagnosis of Streptococcal Pharyngitis by D i f S i P iDetection of Streptococcus pyogenes in Posterior Pharyngeal versus versus Oral Cavity Specimens

Carbohydrate antigen detection, nucleic acid probe detection, and bacterial culture

When testing for GAS pharyngitis, the throat throat remains the optimumremains the optimum site for samplingremains the optimumremains the optimum site for sampling

Streptococcal pharyngitisp p y g

Pharyngitisy gGroup A streptococci (GAS)

INOCULATION OF CULTURE MEDIA 1 4INOCULATION OF CULTURE MEDIA 1+ to 4+



St tStreptococcus pyogenes

Gram-positive cocci in pairs and chains

Catalase-negative

Beta-hemolytic colonies large colony >>00..5 5 mmmm in diameter on sheep BAP after 24 hours incubation

Colonies are usually dry, peaked, or convex with a sharp periphery to the zone of hemolysisperiphery to the zone of hemolysis

Group A Streptococci (GAS)h bl don sheep blood agar

< < 11% % NonhemolyticNonhemolyticyy

Medium and Atmosphere of Medium and Atmosphere of p fp fincubation incubation 24 24 & & 48 48 hrs .(hrs .(9696%)%)

Medium and Atmosphere of Medium and Atmosphere of p fp fincubation incubation 24 24 & & 48 48 hrs ,hrs ,OLDOLD

Sheep blood agar with Bacitracin p gincubated aerobically • Presumptive Identification Of GAS• Reduces Sensitivity & Specificity

Sheep blood agar with Bacitracin & SXT incubated aerobically y

Group A Streptococci (GAS)p p ( )on sheep blood agar

Group A Streptococci (GAS)p p ( )on sheep blood agar

Group A Streptococci (GAS)Group A Streptococci (GAS)

Bacitracin : S/rare R & SXT : R

P lid l l idPyrrolidonyl arylamidase (PYR): +

Serogrouping by particle agglutination approaches 100% accuracyy

Group A Streptococci (GAS)p p ( )Bacitracin 0.04 S>1 or 1212--1515mmmm

Group B StreptococciGroup B Streptococcip pp pare are notnot associated with pharyngitisassociated with pharyngitis

Group A Streptococci (GAS) vs.p p ( )Group B StreptococciGroup B Streptococci

Group B StreptococciGroup B Streptococcip pp pCAMPCAMP

Group B StreptococciGroup B Streptococcip pp pHippurate Hydrolysis : Hippurate Hydrolysis : ++

Group B streptococciGroup B streptococciB i iB i i RR && SXTSXT RRBacitracinBacitracin :R rare s :R rare s && SXTSXT : R: R

G C d G St t iGroups C and G Streptococci

Groups C and G streptococci produce infections fquite similar to GAS but milder than those of group A strains

Some strains contain fibrinolysins and streptolysins and infections can stimulatestreptolysins and infections can stimulate antistreptolysin O titers (ASO), similar to S. pyogenes.

Groups C and G StreptococciGroups C and G Streptococcip pp pBeta-hemolytic Streptococci

Most of the evidence ofMost of the evidence of Lancefield groups C and G Streptococci causing pharyngitispharyngitis comes frompharyngitispharyngitis comes from reports of outbreaks

G C St t iGroup C Streptococci

The beta-hemolytic group CThe beta hemolytic group C Streptococci infecting humans include the large colony (>0.5 mm)include the large colony ( 0.5 mm)

S d l ti b i i ili thS.dysgalactiae subsp. equisimilis,the most common human isolate.

G G St t iGroup G Streptococci

Lancefield group G streptococci are f g p psubdivided into the "large colony" form and the "minute colony“ form (S. anginosus , VP : + )

The "minute colony ( < 0.5 mm) form is not thought to cause pharyngitis.not thought to cause pharyngitis.

G C d G t t iGroups C and G streptococci

Groups C and G streptococci are usually, but not usually, but not yyexclusively, beta hemolytic exclusively, beta hemolytic

Unlike GAS, which are inhibited by 0.04 units/mL of bacitracin, the group C and G isolates are extremely variable in their bacitracinisolates are extremely variable in their bacitracin sensitivity, ranging from as few as 6 6 to to 8 8 percent percent to as many as to as many as 30 30 to to 67 67 percentpercent

Groups C and G Streptococcip pSXT : S & Bacitracin :R-s

Groups C Streptococcip pSXT : S & Bacitracin :R-s

Groups C Streptococcilatex agglutination for Serogroupinglatex agglutination for Serogrouping

S.dysgalactiae subsp. equisimilis

Reportingp g

NO β-hemolytic Streptococci isolated .No Streptococcus pyogenes isolated.Streptococcus pyogenes isolated. 1+... 4+β h l i S i G C / G i l dβ-hemolytic Streptococci ,Group C / G isolated.

Beta-hemolytic StreptococciBeta-hemolytic Streptococci

.

A b t i h l tiArcanobacterium haemolyticum

Formerly Corynebacterium haemolyticum

TonsillitisTonsillitis, pharyngitispharyngitis and causing rash in young adults (15 to 25 years old) andyoung adults (15 to 25 years old) and occasionally in children

It is suggested that in cases of treatment failure and repeat incidences of tonsillitis, isolation of A. A. hemolyticumhemolyticum should be consideredhemolyticumhemolyticum should be considered


Treatment of pharyngitis withTreatment of pharyngitis with penicillin may fail to eradicate

Erythromycin has also been used in h f A h l ithe treatment of A. haemolyticum

infections


After 48 hours incubation on blood agar A. A. f ghaemolyticumhaemolyticum colonies exhibit narrow zones of ß -hemolysis and are 0.5mm in diameter

In cases where A. haemolyticumA. haemolyticum is suspected, incubation of culture plates may need to be extended up to 72h


CO2-enriched atmosphere

A. haemolyticum, whose hemolysis is more pronounced on human and rabbit blood agarpronounced on human and rabbit blood agar than on SBA

Two different biotypes of A. hemolyticum• Smooth type isolated mainly from wounds• Rough type isolated mainly from respiratory tracts• Rough type isolated mainly from respiratory tracts


The majority of A. haemolyticum isolatesThe majority of A. haemolyticum isolates produce small, dark pits under coloniesgrowing on ordinary BA mediumgrowing on ordinary BA medium

Th itti f th d th thThe pitting of the agar underneath the colony, when the colony is pushed aside


A. haemolyticumA. haemolyticum is a catalase-negative, gram-yy g , gpositive or variable rod whose morphology is dependent on the growth media and conditions

Similar to that of C. pseudotuberculosisC. pseudotuberculosis and C. C. ulceransulcerans , positive reverse CAMP test•• A. haemolyticumA. haemolyticum is Catalase & Urea negative

Arcanobacterium haemolyticumySBA 48hrs


Arcanobacterium haemolyticum yReverse CAMP testsReverse CAMP tests

Arcanobacterium haemolyticumyReverse CAMP testsReverse CAMP tests

Mixed Aerobic / Anaerobic Infection or Colonization

Borrelia vincentiiBorrelia vincentii and FusobacteriumFusobacterium species are passociated with the infection known as Vincent's angina

It is characterized by ulceration of the pharynx or gums and occurs in adults with poor mouth hygiene or serious systemic disease

VINCENT'S ANGINAVINCENT'S ANGINA

>>2 2 Borrelia & Fusobacterium Borrelia & Fusobacterium / OIF/ OIF

Candida infectionsf

These infections are common in i d fi ii d fi i i i l l d iimmunodeficientimmunodeficient patients particularly during severe NeutropeniaNeutropenia

Patients receiving antibioticsreceiving antibiotics are also prone to fungal infections

CandidaCandida species may rarely cause severe invasive oesophagitisinvasive oesophagitis

C did i f tiCandida infections

Infection of the buccal mucosa, tongue or oropharynx is usually due to Candida albicansCandida albicans

Species of yeast other than C. albicans, such as Candida krusei and Candida glabrata can alsoCandida krusei and Candida glabrata can also occasionally colonize the mouth but are rarely associated with infectionf



S li Gl d I f tiSalivary Glands Infections

SialadenitisSialadenitis or infections of the salivary glands f f y g(parotid, submandibular, sublingual and accessory parotid) include suppurative, chronic suppurative, chronic bacterial and bacterial and viral parotitisviral parotitis

Mumps, influenza and enteroviruses are the usual viral agents of parotitis

MOUTH SWABSMOUTH SWABS

Parotitis Parotitis pus exuding from the parotid glands and is sampled via the mouthsampled via the mouth

The predominant organisms causing suppurative i i h l iparotitis are staphylococci

• Enterobacteriaceae• Other Gram negative bacilli • Vi id t t i• Viridans streptococci • Anaerobes

Chronic bacterial parotitis is due to Staphylococci, or mixed oral aerobes and anaerobesmixed oral aerobes and anaerobes

Culture media, conditions and ,organisms

St h lStaphylococcus aureus

S. aureus has sporadically been reported as a cause of peritonsillar abscessas a cause of peritonsillar abscess

Pus may be aspirated from the abscess and sent for culture

N i i i itidiN i i i itidiNeisseria meningitidisNeisseria meningitidis

Throat swabs may be an aid to diagnosis of meningococcal meningitis

N. meningitidis can be isolated from a throat swab inN. meningitidis can be isolated from a throat swab in about half the cases of invasive meningococcal disease

Th i i l d f h h i lik l b f hThe strain isolated from the throat is likely to be of the same group and type as that isolated from cerebrospinal fluid and blood

L itiLaryngitis

Most caused by viruses RhinovirusInfluenzaAd iAdenovirusParainfluenza : LarygotracheobronchitisM catarrhalisM catarrhalis is the most commonis the most commonM. catarrhalisM. catarrhalis is the most common is the most common bacterial species isolated from adult bacterial species isolated from adult patients with laryngitis patients with laryngitis

E i l ttitiEpiglottitis

Children : 2-6 Life-threateningBacteria ****Bacteria Bacteriologic culture ???Direct swab of epiglottis blood culturesDirect swab of epiglottis, blood culturesDirect swab should be performed only if airway is secureis secure



Most common:H.influenza type b ****

Less common: H i fl t AH. influenzae type A Nontypable HaemophilusHaemophilus parainfluenzaeHaemophilus parainfluenzae Streptococci Staphylococcip y


Throat swabs can be a usefulThroat swabs can be a useful specimen in determining upper airway colonization with H. influenzae type b and are usually yp yonly taken for epidemiologicalstudiesstudies.

Upper Respiratory Tract Infectionspp p y f

Si itiSinusitis

.

Sinusitis

Sinus development is a process that may take up to 20 20 yearsyears although the ethmoid and maxillary sinuses areyearsyears, although the ethmoid and maxillary sinuses are already present at birth

D l f h id d f l i i hDevelopment of sphenoid and frontal sinuses starts in the first few years of life

Sinusitis is a very common infection in early childhood, accounting for about accounting for about 5 5 to to 1010%% of upper respiratory tract of upper respiratory tract infectionsinfections

Sinusitis

It is often underdiagnosed in children because f gthe symptoms are nonspecific

In addition, physical examination and radiologyare of little value in young children

Etiologic diagnosis requires culturing an aspirate of sinus secretionsaspirate of sinus secretions

Acute Sinusitis DiagnosisgPediatrics/ 01/30/2009

Patient age at which pediatricians reported first g p p fconsidering the diagnosis of acute sinusitis 0 to 5 months in 6%6 to 11 months in 17%12 to 23 months in 36%24 to35 months in 21%,36 months or older in 20%36 months or older in 20%

Acute Sinusitis DiagnosisgPediatrics/ 01/30/2009

Purulent rhinorrhea (55%)( )Nasal congestion (43%)The minimal number of days of symptomsThe minimal number of days of symptoms before considering the diagnosis of sinusitis 10 to 13 days for 37%14 to 16 days for 38%14 to 16 days for 38%

Si itiSinusitis

Viral upper respiratory tract infection isViral upper respiratory tract infection is an important cause of acute sinusitisRhinovirusesRhinovirusesInfluenza virusParainfluenza virus Adenovirus

Sinusitis

The etiology of community-acquired gy f y qinfection may be viral, mixed viral-bacterial, bacterial or occasionally fungal

Nosocomial infection is usually bacterial f yor occasionally viral ,nasotracheal intubation

Sinusitis

Acute sinusitis ( 10 to 30 days) yChronic disease (30 to 120 days)S. pneumoniae, H. influenzae (non-encapsulated ) & M. catarrhalis most frequently isolated bacterial S pneumoniae 30 40%S. pneumoniae 30 - 40%H. influenzae and M. catarrhalis each account for approximately 20% of casesfor approximately 20% of cases

Si itiSinusitis

Group A streptococcusGroup A streptococcus, other α-haemolytic yStreptococci, S.aureus, & anaerobic bacteria

Si itiSinusitis

Nosocomial sinusitisThe most common bacterial isolates :S. aureusP.aeruginosaS.marcesensK iK.pneumoniaeEnterobacter spp. & P.mirabilis.The condition is often polymicrobialThe condition is often polymicrobial

Si itiSinusitis

Occasionally, fungi cause of community-Occasionally, fungi cause of communityacquired sinusitis, particularly in tropical and subtropicaland subtropical

F l i f ti ll d tFungal infections are usually due to filamentous fungi

Si itiSinusitis

Aspergillus spp. (especially Aspergillus flavus), Rhizopus and Mucor f ), p

Candida spp and CryptococcusCandida spp and Cryptococcus neoformans are other causes of infections in patients who are immunocompromisedp p

Ch i hi i iti (CRS)Chronic rhinosinusitis (CRS)

Chronic rhinosinusitis (CRS) is defined as ( ) fan inflammatory disease of the nasal and paranasal mucosa persisting and symptomatic for longer than 3 months

The etiology and pathogenesis of the disease are still unknown

Frequency and Identification of Fungal Strains in Patients with Chronic RhinosinusitisIranian Journal of Pathology (2008)3 (3), 135 - 139

Fungal infection is frequent in patients with g f fchronic rhinosinusitis

Positive fungal cultures of paranasal sinusesmucus were seen in 49% of cases and 5% of controlscontrols

Aspergillus was the most frequentAspergillus was the most frequent

Si itiSinusitis

Chronic sinusitisS. pneumoniaeH. influenzaeStreptococci of the “anginosus” groupStreptococci of the anginosus group M. catarrhalisS. aureusPseudomonas speciesAnaerobesAnaerobes• Aerobic Gram-negative bacteriaAerobic Gram-negative bacteria


The gold standard for making a microbialThe gold standard for making a microbial diagnosis of sinus infection is direct sinus puncture and aspiration.puncture and aspiration.

Thi i i d t ti ll i f lThis invasive and potentially painful procedure is not appropriate for use in

ti di l tiroutine medical practice


Cultures of nasal secretions orCultures of nasal secretions or of nasal swabs are unreliable indicators of the pathogen causing acute infectioncausing acute infection

Culture media, conditions and ,organisms

N bNose swab

Nasal colonization with S. aureus /MRSA

Klebsiella ozaenae

Ozaenia (ozena) is a chronic atrophic rhinitis, Th di i d h d iThe condition can destroy the mucosa and is characterized by a chronic, purulent and often foul-smelling nasal dischargefoul smelling nasal discharge

Streptococcus pneumoniaStreptococcus pneumonia

.

Streptococcus pneumoniaeStreptococcus pneumoniaeArchives of Internal Medicine, September 27, 2010

Positive pneumococcal urinary antigen test result y gin adult patients hospitalized with community-acquired pneumonia (CAP)/ ImmunochromatographicImmunochromatographic

Specificity of the pneumococcal urinary antigenSpecificity of the pneumococcal urinary antigen test was 96% and that its positive predictive value ranged from 88.8% to 96.5%

St t iStreptococcus pneumonia

Gram-positive cocci in pairs and chains

Catalase-negative

Alpha hemolytic on sheep BAP

Colonies are usually transparent, slightly mucoid, or flattened (resemble a checkers playing piece), not peaked

St t iStreptococcus pneumonia

S iS. pneumoniae

S iS. pneumoniae

S iS. pneumoniae

O t hi S tibilitOptochin Susceptibility

Disk containing optochin (5 μgg p ( μgethylhydrocuprein hydrochloride)

SBA plate

Plate is incubated overnight at Plate is incubated overnight at 3535°° C C in in COCO22COCO22

O t hi S tibilitOptochin Susceptibility

A zone of inhibition greater than 14 mm z f gwith a 6-mm disk

A zone of inhibition greater than 16 mm with a 10-mm disk are considered susceptible and a presumptive identification of S. pneumoniae

S. PneumoniaeOptochin susceptibility test > 14 or > 16 mm

Streptococcus pseudopneumoniaep p p2004

A newly Streptococcus pseudopneumoniaeA newly Streptococcus pseudopneumoniae discovered organism

S. pseudopneumoniae strains do not have l lpneumococcal capsules

Streptococcus pseudopneumoniaep p p2004

Streptococcus pseudopneumoniae are resistant to optochin (inhibition zones, less than 14 mm) when they are incubated under an atmosphere of increased CO2increased CO2

But are susceptible to optochin (inhibition zonesBut are susceptible to optochin (inhibition zones, >14 mm) when they are incubated in ambient atmospheres ; False Positive

S. PneumoniaeS. PneumoniaeThe bile solubility 2% sodium deoxycholate/ 2hrs

HaemophilusHaemophilus.

H hilHaemophilus

H hilHaemophilus

H hilHaemophilus

H influenzaeH. influenzaeappear as large colorless to gray,colorless to gray, opaque colonies with no discoloration of the surrounding medium.

HaemophilusHaemophilusSBA vs. Chocolate agar

hil “Q d” l / 5% h bl dHaemophilus ID “Quad” Plates/ 5% horse blood

X XVX

VV Horse

Moraxella catarrhalisMoraxella catarrhalis

.

M ll t h liMoraxella catarrhalis

Formerly called BranhamellaBranhamella catarrhaliscatarrhalis

M. M. catarrhaliscatarrhalis is now considered an important h i i i f i b h ipathogen in respiratory tract infections, both in

children and in adults with underlying COPD

M. M. catarrhaliscatarrhalis may be the single cause of sinusitis, otitis media –much higher in children , gthan adult


B-lactamase-producing strains,B lactamase producing strains, which now account for approximately 90 % of isolates90 % of isolates

S tibl t i illi l l iSusceptible to amoxicillin- clavulanic acid, cefixime, ciprofloxacin


Colony morphology; lack ofColony morphology; lack of pigmentation of the colony on blood agaragar

Growth at 22°C on nutrient agar


In typical Gram stains, M. catarrhalis presents itself as a gram-negative diplococcus with flatteneddiplococcus with flattened abutting sides

The bacterium has a The bacterium has a tendency to resist tendency to resist destainingdestainingdestainingdestaining


Colonies on blood agar are nonhemolytic, round, opaque, convex, and grayish whitegrayish white

The colony remains intact when pushed across the surface of the agaragar


IdentificationIdentificationOxidase : PositiveDNase production : PositiveDNase production : PositiveReduction of nitrate and nitrite : PositiveTributyrin hydrolysis / Butyrate Disk : PositiveTributyrin hydrolysis / Butyrate Disk : PositiveFailure to produce acid from glucose, maltose, sucrose, lactose, and fructose

Kovac’s oxidase & Butyrate Disk in y2 minute

Ocular InfectionsOcular Infections.

O l St t & I f tiOcular Structures & Infections

ConjunctivaConjunctiva• Conjunctivitis

Eyelids• Blepharitis: inflammation of the lid margins


CorneaCornea• Keratitis

Sclera• Scleritis


OrbitOrbit• Orbital cellulitis

lacrimal Apparatus• Dacryoadenitis• Canaliculitis• Dacryocystitis

D titiDacryocystitis

Dacryocystitis the most common infectionDacryocystitis the most common infection of the lacrimal apparatus.

Infections are usually seen in infants, and i t d ith b t ti f thare associated with obstruction of the

nasolacrimal sac.

D titiDacryocystitis


Vitreous Chamber is filled with aVitreous Chamber is filled with a gelatinous material (comprising 99‘% water, collagen fibers, and hyaluronicwater, collagen fibers, and hyaluronic acid) and makes up about two thirds of the volume of the eyevolume of the eye

E d hth l itiEndophthalmitis


Uveal Tract is the middle layer of theUveal Tract is the middle layer of the ocular system and consists of the iris, ciliary body, and choroidsciliary body, and choroids

U itiUveitis

C j tiConjunctiva

The conjunctiva is a mucous membraneThe conjunctiva is a mucous membrane

It li th d l lid dIt lines the upper and lower lids and constitutes the front line of defense against i di iinvading organisms

C j tiConjunctiva

The tears that keep the conjunctiva moistp j

The tears contain many enzymes and otherThe tears contain many enzymes and other factors (Ig A , lysozyme , lactoferrin)

Cooler ocular surface temperatures also inhibit survival of many microorganismsf y g

Ocular Resident Biota (Flora) from Noninflamed Eyes

C j ti itiConjunctivitis

Conjunctivitis is the most common ocular jcomplaint, includes all age groups, and occurs worldwide

Symptoms may include itching, tearing, foreign body sensation, discharge (purulent , watery), and hyperemia or "red eye."


Red eye constitutes more thanRed eye constitutes more than 50% of the office visits to ophthalmologists and is the most common ocular source for fmicrobiologic evaluation


Conjunctivitis may be acute, hyperacute,Conjunctivitis may be acute, hyperacute, subacute, or chronic

The etiologic agents are usually bacterial i l lth h ti t hor viral, although some patients have

fungal or parasitic infections

Microorganisms Associated with Conjunctivitis


Acute bacterial conjunctivitis is generallyAcute bacterial conjunctivitis is generally self-limiting and resolves within 10 to 14 daysdays

If t t d th diti l i 1 tIf treated, the condition may resolve in 1 to 3 days


Corneal involvement may followCorneal involvement may follow conjunctivitis and compromise vision

Chronic infections are more difficult to d lt i l t lmanage and result in long-term ocular

morbidity and compromised vision

A t B t i l C j ti itiAcute Bacterial Conjunctivitis

In warm climates , S. aureus is the mostIn warm climates , S. aureus is the most frequently isolated pathogen

S. pneumoniae may be the most common i l t i ith l t tisolate in areas with cooler temperatures.


H. influenzae, S. aureus , S. pneumoniae,H. influenzae, S. aureus , S. pneumoniae, and other Streptococcus spp. and members of the Enterobacteriaceae are the mostof the Enterobacteriaceae are the most frequently isolated organisms from infants and children with acute conjunctivitisand children with acute conjunctivitis


N gonorrhoeae andN.gonorrhoeae and N.meningitidis cause a hyperacute conjunctivitis that produces huge amounts of exudate that runs fdown the face of the patient.

Ch i B t i l C j ti itiChronic Bacterial Conjunctivitis

The microorganisms that haveThe microorganisms that have been isolated include coagulase-negative staphylococcal species, S. aureus , and Propionibacterium , pacnes

B t i l C j ti itiBacterial Conjunctivitis

Bacterial conjunctivitis can also be causedBacterial conjunctivitis can also be caused by instillation of contaminated cosmetics or medicationsor medications

S St h l id idiS. aureus , Staphylococcus epidermidis, Corynebacterium spp., P. aeruginosa ,

d P t i biliand Proteus mirabilis


Conjunctival scrapings areConjunctival scrapings are collected using a Kimura spatula,, or sterile swab and plated directly onto slides and culture media.

Ki t lKimura spatula

L b t Di iLaboratory Diagnosis

Routine stains (Gram, Giemsa) andRoutine stains (Gram, Giemsa) and culture should reveal the etiologic agent in most acute casesmost acute cases

C lt d b f l l iCulture and smears may be of less value in establishing the etiologic agent in chronic

j ti iticonjunctivitis

L b t Di iLaboratory Diagnosis

Smears and cultures should be collected inSmears and cultures should be collected in all cases of purulent, membranous, or pseudomembranous conjunctivitispseudomembranous conjunctivitis

L b t k i d t f llLaboratory workup is mandatory for all neonatal and infant conjunctivitis

C ltCulture

Chocolate agarChocolate agarBlood agarMMac agarSabouraud agar

Ocular Plating Guide

Contact lens

OTITISOTITISEar Infections

Otiti tOtitis externa

In general infection of theIn general, infection of the external auditory canal yresembles infection of skin and soft tissue

Otitis Externa

Otitis externa can take an Acute or a Chronic form

Acute form affecting 4 in 1,000 (0.4%)persons annually

Chronic form affecting 3% to 5 % of the population

Acute disease commonly results from bacterial (90 percent of cases) or fungal (10 percent of cases)

Otitis Externa

Chronic disease often is part of a more f p fgeneralized dermatologic or allergic problem

The chronic form is commonly of a fungal f y f f gor allergic origin or is the manifestation of dermatitides

Otitis Externa

Acute OE is unilateral in 90 percent of patientsp

Peaks in persons 7 to 12 years of age, declines after 50 years of agedeclines after 50 years of age

Otiti E tOtitis Externa

Approximately 50 percent of bacterialApproximately 50 percent of bacterial cases involve Pseudomonas Pseudomonas aeruginosaaeruginosa followed in incidence byaeruginosaaeruginosa, followed in incidence by Staphylococcus aureusStaphylococcus aureus and then

i bi d bivarious aerobic and anaerobic bacteria

Hypersensitivity reaction to neomycin &

M li t t l titiMalignant external otitis Pseudomonas aeruginosa

M ti i f tiMycotic infection

Mycotic infection of the ear is a superficial, chronic or subacute infection of the external auditory canal

Partial deafness can occur due to occlusion of the earPartial deafness can occur due to occlusion of the ear canal by hyphae.

Aspergillus speciesYeasts

Desquamating epithelium, soft & l t di h &cerumen & purulent discharge &

Aspergillusp g

A Study on the Frequency of Fungal Agents in Otitis Externa in Semnan

Iranian Journal of Pathology (2006)1 (4), 141-144

Otomycosis was diagnosed in 8 (11. 4%) ofOtomycosis was diagnosed in 8 (11. 4%) of 70 cases

Candida parapsilosis (5 cases)Candida glabrata (2 cases) Candida.krusei (1 case)

A t titi di i f tiAcute otitis media infection

Acute otitis media (AOM) is a very frequent y finfection in children.

Before the age of 1 year, around 50% of children have experienced at least one period of AOMAOM

This proportion rises to 70% at the age of 3 yearsThis proportion rises to 70% at the age of 3 years


Acute otitis media is defined by the co-f yexistence of fluid in the middle ear and signs and symptoms of acute illness

Streptococcus pneumoniae 40%p pH.influenzae , nontypeable 30%Moraxella catarrhalis 20%Moraxella catarrhalis 20%


Less frequent causes , specially in children :S.group B in newborn infantS. pyogenesSS. aureusGram-negative bacilliRespiratory syncytial virusRespiratory syncytial virusParainfluenza virusesInfluenza & Adenovirusf

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Upper Respiratory Tract Infections - Dr.Valizadehiacld.ir/DL/modavan/bacteriology/upperrespiratorytract...Ph itiPharyngitis ¾Viruses are the most common cause of pharyngitis in both