Yotsuji A, Minami S, Kakizawa H, Yasuda T, Takai A, Saikawa I, Inoue M, Mitsuhashi S
Antimicrob Agents Chemother. 1985 Dec;28(6):773-7. doi: 10.1128/AAC.28.6.773.
The susceptibility of 53 clinical isolates of Bacteroides fragilis to cephamycins was examined. Judging from the MICs for 50% of the strains tested, moxalactam was the most active, however, judging from the MICs for 90% of the strains tested, cefbuperazone was more effective than moxalactam. A correlation was observed between in vitro activity of benzylpenicillin and cephaloridine and beta-lactamase production. Inactivation due to enzymatic hydrolysis of cephamycins over a short time was not observed; however, inactivation was detected by a double disk diffusion test, and moxalactam was most easily inactivated. We conclude that inactivation due to enzymatic hydrolysis of cephamycins over a long time may play an important role in resistance to some cephamycins in strains of B. fragilis.
检测了53株脆弱拟杆菌临床分离株对头孢霉素的敏感性。从50%受试菌株的最低抑菌浓度（MIC）判断，拉氧头孢活性最强，然而，从90%受试菌株的MIC判断，头孢哌酮比拉氧头孢更有效。观察到苄青霉素和头孢噻啶的体外活性与β-内酰胺酶产生之间存在相关性。未观察到头孢霉素在短时间内因酶水解而失活；然而，通过双纸片扩散试验检测到失活，且拉氧头孢最易失活。我们得出结论，头孢霉素长时间酶水解导致的失活可能在脆弱拟杆菌菌株对某些头孢霉素的耐药性中起重要作用。
