Mycoplasma Infections: Organ Systems, Species & Clinical Syndromes

Mycoplasma species—wall‑less bacteria—cause diverse infections across organ systems. Pathogenicity varies by species and host factors.

Major Species & Associated Syndromes

Species	Primary Site	Clinical Syndromes
M. pneumoniae	Respiratory	Walking pneumonia, tracheobronchitis, pharyngitis; extrapulmonary: encephalitis, Stevens‑Johnson, hemolytic anemia, arthritis
M. genitalium	Urogenital	NGU, cervicitis, PID, preterm birth; macrolide resistance rising
M. hominis	Urogenital	BV‑associated, postpartum fever, neonatal sepsis, pelvic inflammatory disease
M. fermentans	Blood/Immunomodulation	Linked to Gulf War illness, chronic fatigue, rheumatoid arthritis (controversial)
M. penetrans	Urogenital/Respiratory	HIV‑associated, respiratory in immunocompromised
Ureaplasma urealyticum/parvum	Urogenital	NGU, chorioamnionitis, neonatal respiratory distress

Organ‑System Manifestations

• Respiratory: Atypical pneumonia (gradual onset, dry cough, headache, low‑grade fever); CXR often worse than exam.
• Urogenital: Urethritis, cervicitis, PID; often asymptomatic.
• Dermatologic: M. pneumoniae → Stevens‑Johnson, erythema multiforme.
• Hematologic: Cold agglutinin hemolytic anemia (M. pneumoniae).
• Musculoskeletal: Septic arthritis (rare), reactive arthritis.
• CNS: Encephalitis, transverse myelitis, Guillain‑Barré (M. pneumoniae).

Diagnosis

• NAAT (PCR) — gold standard (respiratory, urogenital).
• Serology (IgM/IgG) — M. pneumoniae only; paired titers.
• Culture — slow (weeks), specialized media; rarely clinical.

Treatment

• Macrolides (azithromycin): First‑line; resistance ↑ (esp. M. genitalium in Asia).
• Tetracyclines (doxycycline): Alternative; >8 yrs.
• Fluoroquinolones (moxifloxacin): Resistant cases; >18 yrs.
• Duration: 5–14 days depending on site/severity.