Transcript Mycoplasma and Ureaplasma172.5 KB

Mycoplasma and Ureaplasma
Mollicutes
is subdivided into five
families
200 species
five species are associated with
human disease
Mycoplasma
pneumoniae
Mycoplasma and Ureaplasma
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Mycoplasma and Ureaplasma
organisms are the smallest free-living
bacteria
they do not have a cell wall
sterols
form pleomorphic filaments
0.1 to 0.3 μm
Mycoplasma and Ureaplasma
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binary fission
grow on artificial cell-free media
both RNA and DNA
Mycoplasmas are facultatively
anaerobic (except M. pneumoniae,
which is a strict aerobe)
Mycoplasma and Ureaplasma
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fried-egg appearance
major antigenic determinants are
membrane glycolipids and proteins
M. pneumoniae is an extracellular
pathogen
adheres to the respiratory epithelium
Mycoplasma and Ureaplasma
Mycoplasma and Ureaplasma
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Acts as superantigen
Worldwide disease with no seasonal
incidence
Children between ages 5 and 15 years
Transmitted by inhalation
Strict human pathogen
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Epidemic disease occurs every 4 to 8 years
Nasal secretions spread M. pneumoniae
infection
partially immune from previous exposure
15% of sexually active men and women
colonized with M. Hominis
45% to 75% colonized with Ureaplasma
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mild upper respiratory tract disease
Low-grade fever, malaise, headache, and a
dry, nonproductive cough
Symptoms gradually worsen over the next
few days and can persist for 2 weeks or
longer
More severe disease with lower respiratory
less than 10% of patients
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primary atypical pneumonia
with a patchy bronchopneumonia
myalgias and gastrointestinal tract
symptoms are uncommon
otitis media, erythema multiforme (StevensJohnson syndrome), hemolytic anemia,
myocarditis, pericarditis, and neurologic
abnormalities
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M. genitalium and U. urealyticum can cause
nongonococcal urethritis
M. hominis implicated as a cause of pyelonephritis,
pelvic inflammatory disease, postpartum fever
recovery of the bacteria from specimens from
infected patients
a serologic response to the organism
clinical improvement after treatment with specific
antibiotics
demonstration of disease in animal models
combination of these findings
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Microscopy not useful
Culture slow
Molecular diagnosis
Serology
o Complement fixation
o Enzyme immunoassays
o Cold agglutinin
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Erythromycin, tetracycline (or doxycycline ),
and newer fluoroquinolones
Erythromycin is used to treat Ureaplasma
infections, because these organisms are
resistant to tetracycline
M. hominis is resistant to erythromycin and
occasionally to the tetracyclines.
Clindamycin has been used to treat
infections caused by these resistant strains.