MycoplasmMycoplasmaa

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AIMSRCAIMSRC

MycoplasmataceaeMycoplasmataceae Two genera Two genera

– Mycoplasma Mycoplasma – UreaplasmaUreaplasma

Smallest free living bacteriaSmallest free living bacteria Do not have a cell wallDo not have a cell wall

– Resistant to cell wall acting antibioticsResistant to cell wall acting antibiotics Cell membrane contains sterolsCell membrane contains sterols Slow growing & Facultative anaerobeSlow growing & Facultative anaerobe Do not stain by ordinary methodsDo not stain by ordinary methods Morphology : Highly pleomorhicMorphology : Highly pleomorhic

Mycoplasma Mycoplasma (Scanning EM)(Scanning EM)

Important human Important human pathogenspathogens Mycoplasma pneumoniaeMycoplasma pneumoniae

– Eaton’s agentEaton’s agent– Pleuropneumonia like organism Pleuropneumonia like organism

(PPLO)(PPLO) Mycoplasma hominisMycoplasma hominis Mycoplasma genitaliumMycoplasma genitalium Ureaplasma urealyticumUreaplasma urealyticum

Organism Disease

M. pneumoniae Upper respiratory tract disease,tracheobronchitis, atypicalpneumonia, (chronic asthma??)

M. hominis Pyleonephritis, pelvicinflammatory disease,postpartum fever

M. genitalium Nongonococcal urethritis

U. urealyticum Nongonococcal urethritis,(pneumonia and chronic lungdisease in premature infants??)

Diseases Caused by Mycoplasma

Mycoplasma Mycoplasma pneumoniaepneumoniae Strict human pathogenStrict human pathogen Attaches by P1 pili to ciliary base Attaches by P1 pili to ciliary base

on epithelial cellon epithelial cell Disease spreads by inhalation of Disease spreads by inhalation of

aerosolsaerosols Spreads among close contactsSpreads among close contacts Disease seen worldwideDisease seen worldwide

Mycoplasma Mycoplasma pneumoniaepneumoniae DiseasesDiseases

– Upper respiratory tract diseasesUpper respiratory tract diseases– TracheobronchitisTracheobronchitis– Primary atypical pneumoniaPrimary atypical pneumonia– Complications Complications

neurological abnormalities, neurological abnormalities, myo/pericarditismyo/pericarditis hemolytic anemiahemolytic anemia

Atypical pneumoniaAtypical pneumoniaM. pneumoniaeM. pneumoniae

Incubation - 2-3 weeksIncubation - 2-3 weeks Fever, headache and malaiseFever, headache and malaise Persistent non-productive coughPersistent non-productive cough Respiratory symptomsRespiratory symptoms

– Radiological signs precede symptomsRadiological signs precede symptoms Organisms persist Organisms persist Slow resolutionSlow resolution Rarely fatalRarely fatal

LAB Diagnosis- LAB Diagnosis- M M pneuminiaepneuminiae

SpecimenSpecimen Respiratory secretionsRespiratory secretions SerumSerum

Laboratory Diagnosis - Laboratory Diagnosis - M. M. pneumoniaepneumoniae

MicroscopyMicroscopy– Difficult to stainDifficult to stain– Can help eliminate other organismsCan help eliminate other organisms

Culture (Culture (definitive diagnosisdefinitive diagnosis))– Sputum or throat washingsSputum or throat washings– Special transport medium neededSpecial transport medium needed

High index of suspicion - High index of suspicion - M. pneumoniaeM. pneumoniae– May take 2-3 weeksMay take 2-3 weeks

Culture media usedCulture media used PPLO broth and agarPPLO broth and agar Serum is necessary for growthSerum is necessary for growth In broth, growth indicated by pH In broth, growth indicated by pH

change due to carbohydrate change due to carbohydrate metabolismmetabolism

Colonies best seen under microscope Colonies best seen under microscope – Diene’s staining technique– Diene’s staining technique

M pneumoniae M pneumoniae coloniescolonies

SerologySerology Very useful as culture is technically Very useful as culture is technically

demandingdemanding Specific and nonspecific serological testsSpecific and nonspecific serological tests Specific testsSpecific tests

– Complement Fixation, ELISA, IFAComplement Fixation, ELISA, IFA Non specific testsNon specific tests

– Streptococcus MG agglutination test Streptococcus MG agglutination test – Cold agglutinin test with human O RBCs. Cold agglutinin test with human O RBCs.

Significant titer is > 1:128.Significant titer is > 1:128.

Treatment - Treatment - M. pneumoniaeM. pneumoniae

Treatment Treatment – Tetracycline or erythromycinTetracycline or erythromycin– Can’t use cell wall synthesis Can’t use cell wall synthesis

inhibitorsinhibitors

Genital mycoplasmaGenital mycoplasma M.hominisM.hominis M.genitaliumM.genitalium Ureaplasma urealyticumUreaplasma urealyticum

Organism Disease

M. pneumoniae Upper respiratory tract disease,tracheobronchitis, atypicalpneumonia, (chronic asthma??)

M. hominis Pyleonephritis, pelvicinflammatory disease,postpartum fever

M. genitalium Nongonococcal urethritis

U. urealyticum Nongonococcal urethritis,(pneumonia and chronic lungdisease in premature infants??)

Diseases Caused by Mycoplasma

M. hominisM. hominis, , M. genitaliumM. genitalium and and U. urealyticumU. urealyticum

Laboratory diagnosisLaboratory diagnosis– Culture (except Culture (except M. genitaliumM. genitalium))– Fried egg appearence of colonies on Fried egg appearence of colonies on

PPLO agarPPLO agar

Mycoplams Mycoplams spp -Coloniesspp -Colonies

Differentiation of SpeciesDifferentiation of Species

M. pneumoniae – M. pneumoniae – ferments ferments glucoseglucose

M. hominisM. hominis – Hydrolyses – Hydrolyses ArginineArginine U. urealyticumU. urealyticum – Hydrolyses – Hydrolyses UreaUrea M. genitaliumM. genitalium - difficult to culture - difficult to culture

Genital MycoplasmosisGenital Mycoplasmosis - -TreatmentTreatment

Tetracycline orTetracycline or ErythromycinErythromycin