Mycoplasma Flashcards
1
Q
Features & examples of mycoplasma & ureaplasma
A
- No peptidoglycan - no cell wall - resistant to penicillins & cephalosporins
- Mycoplasma pneumoniae
- Others - Mycoplasma hominis (fried egg colonies), Mycoplasma genitalium, Ureaplasma urealyticum
2
Q
Clinical presentations of M. pneumoniae
A
Respiratory Tract Infection (upper & lower)
- Walking pneumonia - not seriously ill, rarely need hospitalisation, patchy opacities (consolidation) on CXR
- Paroxysmal cough - in children, confused w whooping cough
- Severe in sickle cell/immunocompromised
- Complications: SJS/rashes (hypersensitivity), joint pain, encephalitis, meningitis, hemolytic anemia, myocarditis, pericarditis
3
Q
Diagnosis of M. pneumoniae
A
- Serology
- cold agglutinins produced in 50% of patients - Ab that react w I antigen on human RBCs, most easily detectable at 4C
- specific serology eg complement fixing test (observe rising titre bw paired acute & convalescent sera) & IgM assays, more sensitive in children - Culture is possible on cell free media but difficult
4
Q
Treatment of M. pneumoniae
A
- Do not use cell wall agents, resistant to penicillins & cephalosporins
- Erythromycin (or other macrolides, tetracyclines, fluoroquinolones), 2-3 weeks
5
Q
Clinical presentations of other mycoplasmas/ureaplasmas
A
- Post-gonococcal/Non-gonococcal urethritis (NGU) - U. urealyticum/M. genitalium
- UTI & renal stones - U. urealyticum contributes to renal calculi formation, M. hominis can cause acute pyelonephritis
- Female Reproductive Tract - involved in bacterial vaginosis, M. hominis & M. genitalium can cause PID
- Pregnancy & newborn - M. hominis & ureaplasmas - post-abortion & post-partum fever, meningitis in premature neonates, RTIs in neonates
- Immunocompromised
- congenital hypogammaglobulinemia - prone to severe M. pneumoniae inf, joint inf, hard to treat
- post-transplant infections eg sternal wound inf (heart & lung transplants), septicemia by M. hominis
