189.2 📚 國考版

189.2.0.1 必背 — Microbiology

• NO cell wall → β-lactam useless
• Smallest free-living organism
• Cholesterol membrane (unique among bacteria)

189.2.0.2 必背 — M. pneumoniae

• Walking pneumonia young adult / school-age
• Gradual onset, dry cough, low fever
• CXR > exam findings
• Extrapulmonary: cold agglutinin hemolysis, erythema multiforme, MIRM, encephalitis, GBS, ADEM, myocarditis
• 2023-2024 global outbreak post-COVID

189.2.0.3 必背 — Treatment

• Macrolide first-line (azithromycin) but Asia R 50-90%
• Doxycycline alt
• FQ alt
• Severe extrapulmonary: extended duration + steroid

189.2.0.4 必背 — Cold Agglutinin Disease

• Anti-I IgM antibody → cold agglutinin hemolysis
• 60% of M. pneumoniae patients
• 1-5% clinical hemolysis

189.2.0.5 必背 — MIRM vs SJS/TEN

• MIRM (Mycoplasma-Induced Rash and Mucositis) — multi-mucosal involvement, less skin, better prognosis
• Distinct from drug-induced SJS/TEN

189.2.0.6 必背 — M. genitalium

• STI, rising recognition
• Macrolide R high (50-80%) → resistance-guided treatment
• Doxy + azithro sequential or doxy + moxifloxacin
• Pristinamycin / lefamulin emerging

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