Ralph E D, Kirby W M
Antimicrob Agents Chemother. 1975 Oct;8(4):409-14. doi: 10.1128/AAC.8.4.409.
The comparative bactericidal activity of penicillin G, carbenicillin, clindamycin, and metronidazole against eight susceptible strains of Bacteroides fragilis and four strains of Clostridium perfringens was determined by performing colony counts anaerobically of cultures incubated in brucella broth. With the B. fragilis strains, there was a lag phase of growth of approximately 8 h, during which time metronidazole did not reduce the colony counts. However, within 4 h of the onset of exponential growth, metronidazole caused an abrupt decrease in counts to less than 100 colonies per ml in all strains tested. Moreover, in two strains in which the bactericidal rate was followed hourly, a 3- to 6-log decrease occurred over 1 h or less. In contrast, penicillin G and carbenicillin caused a gradual decline in colony counts from the start of approximately 1 log for each 8-h interval and were bactericidal for all strains tested. Clindamycin demonstrated the slowest bactericidal activity and for 25% of the strains was only bacteriostatic. With the C. perfringens strains, after a lag phase of 4 h, an abrupt decrease in colony counts also occurred with metronidazole, whereas penicillin and clindamycin again demonstrated more gradual killing effects. These studies showed a unique, time-related bactericidal action of metronidazole as compared with the other three antimicrobial agents.
通过对在布鲁氏菌肉汤中培养的厌氧菌进行菌落计数，测定了青霉素G、羧苄青霉素、克林霉素和甲硝唑对8株脆弱拟杆菌敏感菌株和4株产气荚膜梭菌菌株的杀菌活性比较。对于脆弱拟杆菌菌株，存在大约8小时的生长延迟期，在此期间甲硝唑并未降低菌落计数。然而，在指数生长期开始后的4小时内，甲硝唑使所有测试菌株的菌落计数急剧下降至每毫升少于100个菌落。此外，在两株每小时跟踪杀菌率的菌株中，在1小时或更短时间内菌落数下降了3至6个对数。相比之下，青霉素G和羧苄青霉素从开始起每8小时间隔使菌落计数逐渐下降约1个对数，并且对所有测试菌株均有杀菌作用。克林霉素显示出最慢的杀菌活性，并且对25%的菌株仅具有抑菌作用。对于产气荚膜梭菌菌株，在4小时的延迟期后，甲硝唑也使菌落计数急剧下降，而青霉素和克林霉素再次显示出更缓慢的杀菌效果。这些研究表明，与其他三种抗菌药物相比，甲硝唑具有独特的、与时间相关的杀菌作用。
