125.3 🩺 內科專科考前版

125.3.0.1 1️⃣ Type III Secretion System (T3SS) — “Molecular Syringe”

• Pathogenic Gram - bacteria 用來注射 effector 至 host cell
• 經典: Salmonella, Shigella, Yersinia, P. aeruginosa, E. coli (EPEC, EHEC)
• 為新 antibacterial target

125.3.0.2 2️⃣ Pathogenicity Islands

• 一群 virulence genes 在 mobile genetic element
• Horizontal transfer → new pathogenic strain
• 經典: Enterohemorrhagic E. coli (EHEC) 從 K12 transfer → O157:H7

125.3.0.3 3️⃣ Microbiome interactions

• Commensal microbiota 防止 invasion (colonization resistance)
• 抗生素 → dysbiosis → C. difficile, Candida overgrowth
• FMT (fecal microbiota transplant) — recurrent CDI 標準治療

125.3.0.4 4️⃣ Targeting Virulence — 新治療策略

• Bezlotoxumab (anti-toxin B antibody) — recurrent CDI
• Anti-staph alpha toxin (in clinical trial)
• Anti-quorum sensing agents (research)
• Phage therapy — 對 MDR 增加應用

---