1. Wei-Ping Zhang, PhD 张纬萍 Dept. of Pharmacology, School of Medicine, Zhejiang University weiping601@zju.edu.cn 2012.11.1 General Considerations for antimicrobial agents

2. Overview I. Chemotherapy II. Chemotherapeutic agents III. Mechanisms under the action of chemotherapeutic agents IV. Classification of antimicrobial agents V. Bacterial Resistance VI. Clinical pharmacology of antimicrobial agents

3. The Birth of Modern Chemotherapy: Dreams of a “Magic Bullet” I. Chemotherapy Louis Pasteur 1822-1895 Robert Koch 1843-1910 Rebecca Lancefield 1896-1981

4. Paul Ehrlich introduced an arsenic-containing chemical called salvarsan （阿斯凡纳明） to treat syphilis （梅毒） (1910). –“Magic bullet” for treatment of syphilis I. Chemotherapy 1928 Fleming discovers penicillin

5. History of Antimicrobial Therapy I. Chemotherapy 1928

6. History of Antimicrobial Therapy 1928 Fleming discovers penicillin 1932 Domagk discovers sulfonamides 1940s Penicillin and streptomycin used widely, cephalosporins discovered 1947 Chloramphenicol discovered, first broad spectrum agent 1950s Tetracycline in use 1952 Erythromycin discovered (macrolides) 1956 Vancomycin used for penicillin-resistant S. aureus 1957 Kanamycin discovered (aminoglycosides) 1962 Nalidixic acid discovered (quinolones) 1980s Fluoroquinolones, broad spectrum cephalosporins 2000s Newer agents to combat resistant pathogens I. Chemotherapy

7. History of Antimicrobial Therapy I. Chemotherapy Endless way ……………… Superbug……drug resistance MRSA ， NAM-1

8. Pharmacokinetics Adverse effects pathogenicity Immunologicalresponses Therapeutic Effects Resistance Host Factors ： patient’s age, gender, constitution, hepatic, renal function II. Chemotherapeutic agents

9.  Antimicrobial drugs Antibacterial drugs Antibacterial drugs Antifungal drugs Antifungal drugs Antiviral drugs Antiviral drugs  Antiparasitic durgs  Antineoplastic / anticancer drugs

10. Ideal antimicrobial drugs  High sensitivity  Nontoxic or low-toxic (safety)  Nonresistance  Satisfied pharmacokinetic properties  Good price II. Chemotherapeutic agents

11. Antibacterial drugs ( 抗菌药 )  kill bacteria and arresting its growth  antibiotics and synthetic antimicrobial agents such as sulfonamides( 磺胺类 ) and quinolones ( 喹诺酮类 ). II. Chemotherapeutic agents

12. Antibiotics （抗生素）  Produced by various species of microorganisms (bacteria, fungi, actinomycetes) and semi-synthetic  Suppress the growth of other microorganisms. II. Chemotherapeutic agents

13. Antibacterial spectrum （抗菌谱） Narrow?Narrow? Broad?Broad? Chemotherapetic index (CI) （治疗指数） CI= LD 50 / ED 50CI= LD 50 / ED 50 CI= LD 5 / ED 95CI= LD 5 / ED 95 II. Chemotherapeutic agents

14. Bacteriostatic drugs （抑菌药） inhibit the growth of microorganisms e.g. Sulfonamides, Tetracycline Bactericidal drugs （杀菌药） kill microorganisms kill microorganisms e.g. Penicillin, Aminoglycosides II. Chemotherapeutic agents

15. Bactericidal vs Bacterostatic II. Chemotherapeutic agents

16. Minimum inhibitory concentration (MIC) 最低抑菌浓度 Minimum bactericidal concentration (MBC) 最低杀菌浓度 Post antibiotic effect (PAE) 抗生素后效应 Resistance （耐药性） Cross Resistance （交叉耐药性） First expose effect （首次接触效应） II. Chemotherapeutic agents

17. 最低抑菌浓度 最低杀菌浓度

18. Incubate 18 to 24 hr at 37 ℃ Measure diameters of nongrowthzones Disk diffusion method for testing bacteria for susceptibility to specific antimicrobial drugs. II. Chemotherapeutic agents

19. III. Mechanism of action

20. 1. Inhibit synthesis of bacterial cell walls 2. Affecting permeability of cell membrane and leading to leakage of intracellular compounds 3. Inhibit protein synthesis 4. Affect bacterial nucleic acid metabolism 5. Block essential enzymes of folate metabolism III. Mechanism of action

21. 1.Inhibiting synthesis of bacterial cell walls e.g. penicillins,  -lactams e.g. penicillins,  -lactams III. Mechanism of action

22. 乙酰胞壁酸 -5 肽 UDP- 乙酰葡萄糖胺

23. 2. Affecting permeability of membrane 离子吸附剂  Ionic- sorbent （离子吸附剂） e.g. Aminoglycosides （氨基糖苷类） e.g. Aminoglycosides （氨基糖苷类）  Binding to ergosterol （麦角固醇） e.g. Nystatin ( 制霉菌素 ) e.g. Nystatin ( 制霉菌素 ) Amphotericin B （两性霉素） Amphotericin B （两性霉素）  Cationic detergent e.g. polymyxins （多粘菌素） e.g. polymyxins （多粘菌素） III. Mechanism of action

24. Lipopoly -saccharide Outer membrane Peptidoglycan Cytoplasmic membrane polymyxins 2. Affecting permeability of membrane III. Mechanism of action

25. Ribosomal structure Bacteria 30S + 50S 70S  30S subunit binds mRNA in initiation complex holds growing peptide chain  50S subunit  accepts / translocates charged tRNAs "A" site --> Aminoacyl-tRNA (acceptor) site "P" site --> Peptidyl-tRNA (donor) site Mammals 40S + 60S 80S 3. Inhibiting protein synthesis III. Mechanism of action

26. 3. Inhibiting protein synthesis PA III. Mechanism of action

27. 3. Inhibiting protein synthesis PA III. Mechanism of action 氨基糖苷类 四环素 大环内酯类 氨基糖苷类 氯霉素 林可霉素

28. 4. Affecting bacterial nucleic acid metabolism quinolones (-) Break back segment (+) (-) III. Mechanism of action  Rifampicin ( 利福平 ): inhibit DNA- dependent RNA polymerase  Ridarabine ( 阿糖腺苷 ), Ganciclovir ( 更昔洛韦 ) inhibit DAN polymerase

29. Pteridine + PABA Blocked by sulfonamides Dihydropteroic acid Dihydrofolic acid glutamate Tetrahydrofolic acid Blocked by trimethoprim NADPH Dihydropteroate synthase Dihydrofolate reductasease 5. block essential enzymes of folate metabolism III. Mechanism of action 蝶啶对氨基苯甲酸 二氢蝶酸 甲氧苄啶

30. According to bio-activity  Anti G + antibiotic  Anti G - antibiotic  Broad-spectrum antibiotic  Anti mycobacterium ( 分支杆菌 ) antibiotic  Anti anaerobe （厌氧菌） antibiotic   -lactamase inhibitor （  内酰胺酶抑制剂） IV. Classification of antimicrobial drugs

31. According to the chemical structure ： 1.  -lactams (  - 内酰胺类）； Penicillins （青霉素 类）； Cephalosporins （头孢菌素类） ; 2. Aminoglycosides( 氨基糖苷类 ); 3. Macrolides （大环内酯类） ; Lincosamides （林可胺类） ;Vancomycins （万古霉素类） 4. Tetracyclines （四环素类）； Chloramphenicol ( 氯霉素 ) Chloramphenicol ( 氯霉素 ) Antimicrobial drugs -Characteristics IV. Classification of antimicrobial drugs

32. 5. Quinolones ( 喹诺酮类 ) 6. Sulphonamides ( 磺胺类 ) 7. Nitrofurans ( 硝基呋喃类 ) 8. Antimycobacterial agents ( 抗结核分 支杆菌类 ) 9. others: Oxazolidinones （恶唑烷酮类） Oxazolidinones （恶唑烷酮类） Streptogramins （链阳菌素类） Streptogramins （链阳菌素类） IV. Classification of antimicrobial drugs

33.  Intrinsic resistance – Inherent features ， usually expressed by – Inherent features ， usually expressed by chromosomal genes chromosomal genes  Acquired resistance – Emerge from previously sensitive bacterial – Emerge from previously sensitive bacterial populations populations – Caused by mutations in chromosomal – Caused by mutations in chromosomal genes genes – Or by acquisition of plasmids or – Or by acquisition of plasmids or transposons transposons V. Bacterial Resistance

35. The drug is not active. The drug is not active. The target is altered. The target is altered. The drug does not reach its target. The drug does not reach its target. Bacterial Resistance- Mechanisms V. Bacterial Resistance

36.  Production of aminoglycoside-modifying enzymes andβ-lactamase; 1.The drug is not active. V. Bacterial Resistance

37. 2.The target is altered Mutation of the natural target (quinolone resistance) Substitution with a resistant alternative to the native, susceptible target (methicillin （甲氧西林） resistance) V. Bacterial Resistance

38. Target modification (ribosomal protection type of resistance to macrolides and tetracyclines) 2.The target is altered V. Bacterial Resistance

39. Absence, mutation or loss of the appropriate transporter or porins ( 膜孔蛋白） 3.The drug does not reach its target V. Bacterial Resistance

40. Active efflux system ( 主 动排出系统 )  Efflux transporter （转运子）  Accessory protein （附加蛋白）  Outer membrane channel （外膜蛋白） 3.The drug does not reach its target V. Bacterial Resistance

41. Active efflux system （主动排出系统 ） transporter Accessory protein Outer membrane channel V. Bacterial Resistance

42.  Mutations 突变  Transduction 转导  Transformation 转化  Conjugation 接合 The transfer of Resistance genes V. Bacterial Resistance  From human  human  From bacteria  bacteria  Intracellular

43. Mutations 突变 V. Bacterial Resistance

44. May occur in the gene encoding  The target protein  A protein involved in drug transport  A protein important for drug activation  A regulatory gene or promoter affecting expression of the target, a transport protein, or an inactivating enzyme Mutations 突变 V. Bacterial Resistance

45. Transduction 转导 V. Bacterial Resistance

46. Transformation 转化Transformation 转化 Conjugation 接合Conjugation 接合 V. Bacterial Resistance

48. Multi-drug resistance (MDR) 1.Methicillin-resistant staphylococcus aureus, MRSA 甲氧西林耐药金黄色葡萄球菌 甲氧西林耐药金黄色葡萄球菌 Methicillin-resistant coagulase Methicillin-resistant coagulase negative staphylococci, MRCNS negative staphylococci, MRCNS 甲氧西林凝固酶阴性葡萄球菌 甲氧西林凝固酶阴性葡萄球菌 PBP-2a （ a 78kD new PBP ） PBP-2a （ a 78kD new PBP ） V. Bacterial Resistance

49. Multi-drug resistance MDR 2.Penicillin-resistant streptococcus pneumoniae, PRSP ，青霉素耐药肺炎链球菌 PRSP ，青霉素耐药肺炎链球菌 PBP-1a, PBP-2a, PBP-2x, PBP-2b （ 78-100 kD ）PBP-1a, PBP-2a, PBP-2x, PBP-2b （ 78-100 kD ） Active efflux system （ express mef(A) 对大环内酯类）Active efflux system （ express mef(A) 对大环内酯类） 3.Vancomycin-resistant Enterococcus, VRE 万古霉素耐药肠球菌 万古霉素耐药肠球菌 PBP avidity ↓PBP avidity ↓ van-A, van-B, van C-1, van C-2, van D, van Evan-A, van-B, van C-1, van C-2, van D, van E V. Bacterial Resistance

50. 4. The 3 rd generation-cephalosporins -resistant Extended spectrumβ-lactamases, ESBLExtended spectrumβ-lactamases, ESBL 超广谱 β- 内酰胺酶 超广谱 β- 内酰胺酶 Class I chromosone mediated β-lactamasesClass I chromosone mediated β-lactamases I 类染色体介导的 β- 内酰胺酶 I 类染色体介导的 β- 内酰胺酶 E.g. 大肠埃希菌、克雷伯肺炎杆菌、阴沟肠杆菌E.g. 大肠埃希菌、克雷伯肺炎杆菌、阴沟肠杆菌 Multi-drug resistance MDR V. Bacterial Resistance

51. 5.Carbapenem ( 碳青霉烯 ) –resistant ：对亚胺培 南的铜绿假单胞菌敏感 OprD porinOprD porin Metalβ-lactamases （金属 β- 内酰胺酶）Metalβ-lactamases （金属 β- 内酰胺酶 ） 6. Quinolone-resistant escherichia coli （大肠 埃希菌）, AREC Active efflux systemActive efflux system Cross-resistanceCross-resistance Multi-drug resistance MDR V. Bacterial Resistance superbug or super bacterium

52. Estimated TB incidence rates, 2009 VI. Clinical pharmacology of antimicrobial agents Treatment with the drug resistence

54. Antimicrobial agents combinations According to their actions, antimicrobial agents can be classified: According to their actions, antimicrobial agents can be classified: ① bactericidal agents for growing bacteria ① bactericidal agents for growing bacteria ② bactericidal agents for resting bacteria ② bactericidal agents for resting bacteria ③ fast bacteriostatic agents ③ fast bacteriostatic agents ④ slow bacteriostatic agents ④ slow bacteriostatic agents VI. Clinical pharmacology of antimicrobial agents

55. Antimicrobial agents combinations According to their actions, antimicrobial agents can be classified: According to their actions, antimicrobial agents can be classified: ① bactericidal agents for growing bacteria ① bactericidal agents for growing bacteria ② bactericidal agents for resting bacteria ② bactericidal agents for resting bacteria ③ fast bacteriostatic agents ③ fast bacteriostatic agents ④ slow bacteriostatic agents ④ slow bacteriostatic agents ① + ② : synergism ① + ② : synergism ① + ③ : antagonism ① + ③ : antagonism ① + ④ : addition or indifference ① + ④ : addition or indifference ③ + ④ : addition ③ + ④ : addition VI. Clinical pharmacology of antimicrobial agents

56. Two is better than one?Two is better than one? –Empiric therapy –Polymicrobial infection –Increase efficacy--synergism –Prevent emergence of resistance Combination therapyCombination therapy –Mycobacterium tuberculosis –HIV –Pseudomonas aeruginosa( 铜绿假单胞菌 ) –? Invasive aspergillosis （侵入性曲霉菌病） Antimicrobial agents combinations VI. Clinical pharmacology of antimicrobial agents

57. First-line agents Isoniazid(INH, 异烟肼 ) Rifampin( 利福平 ) Pyrazinamide( 吡嗪酰胺 ) Ethambutol( 乙胺丁醇 ) Streptomycin( 链霉素 ) Second-line agents Para-aminosalicylic ( 对氨水杨酸 ) Ethionamide( 乙硫异烟胺 ) Amikacin( 阿米卡星 ) Capreomycin( 卷曲霉素 ) Fluoroquinolones ( 氟喹诺酮类 ) VI. Clinical pharmacology of antimicrobial agents