2. MycoplasmataceaeMycoplasmataceae
Two generaTwo genera
– MycoplasmaMycoplasma
– 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
4. Important humanImportant human
pathogenspathogens
Mycoplasma pneumoniaeMycoplasma pneumoniae
– Eaton’s agentEaton’s agent
– Pleuropneumonia like organism (PPLO)Pleuropneumonia like organism (PPLO)
Mycoplasma hominisMycoplasma hominis
Mycoplasma genitaliumMycoplasma genitalium
Ureaplasma urealyticumUreaplasma urealyticum
5. Organism Disease
M. pneumoniae Upper respiratory tract disease,
tracheobronchitis, atypical
pneumonia, (chronic asthma??)
M. hominis Pyleonephritis, pelvic
inflammatory disease,
postpartum fever
M. genitalium Nongonococcal urethritis
U. urealyticum Nongonococcal urethritis,
(pneumonia and chronic lung
disease in premature infants??)
Diseases Caused by Mycoplasma
6. MycoplasmaMycoplasma
pneumoniaepneumoniae
Strict human pathogenStrict human pathogen
Attaches by P1 pili to ciliary base onAttaches by P1 pili to ciliary base on
epithelial cellepithelial cell
Disease spreads by inhalation ofDisease spreads by inhalation of
aerosolsaerosols
Spreads among close contactsSpreads among close contacts
Disease seen worldwideDisease seen worldwide
10. 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
11. 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 changeIn broth, growth indicated by pH change
due to carbohydrate metabolismdue to carbohydrate metabolism
Colonies best seen under microscope –Colonies best seen under microscope –
Diene’s staining techniqueDiene’s staining technique
13. SerologySerology
Very useful as culture is technicallyVery 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 testStreptococcus 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.
14. Treatment -Treatment - M. pneumoniaeM. pneumoniae
TreatmentTreatment
– Tetracycline or erythromycinTetracycline or erythromycin
– Can’t use cell wall synthesis inhibitorsCan’t use cell wall synthesis inhibitors
16. Organism Disease
M. pneumoniae Upper respiratory tract disease,
tracheobronchitis, atypical
pneumonia, (chronic asthma??)
M. hominis Pyleonephritis, pelvic
inflammatory disease,
postpartum fever
M. genitalium Nongonococcal urethritis
U. urealyticum Nongonococcal urethritis,
(pneumonia and chronic lung
disease in premature infants??)
Diseases Caused by Mycoplasma
17. M. hominisM. hominis,, M. genitaliumM. genitalium
andand
U. urealyticumU. urealyticum
Laboratory diagnosisLaboratory diagnosis
– Culture (exceptCulture (except M. genitaliumM. genitalium))
– Fried egg appearence of colonies onFried egg appearence of colonies on
PPLO agarPPLO agar
19. Differentiation of SpeciesDifferentiation of Species
M. pneumoniae –M. pneumoniae – fermentsferments glucoseglucose
M. hominisM. hominis – Hydrolyses– Hydrolyses ArginineArginine
U. urealyticumU. urealyticum – Hydrolyses– Hydrolyses UreaUrea
M. genitaliumM. genitalium - difficult to culture- difficult to culture