III. ANTIMICROBIAL AGENTS USED IN VIVO 体内使用的抗微生物制剂 Selective toxicity选择毒性 Can be used internally可体内使用 Chemotherapeutic agents化学治疗剂 6.6 Synthetic Antimicrobial Drugs 人工合成的抗微生物药物 6.7 Antibiotics: Naturally occurring antimicrobial drugs 抗生素 IV. ANTIMICROBIAL DRUG RESISTANCE AND DRUG DISCOVERY 抗药性与新药研制 6.8 Antimicrobial drug resistance