Sato K, Matsuura Y, Inoue M, Mitsuhashi S
Antimicrob Agents Chemother. 1982 Oct;22(4):579-84. doi: 10.1128/AAC.22.4.579.
A highly penicillin-resistant strain of Bacteroides fragilis, strain GN11499, was found among 80 clinical isolates of the B.fragilis group and appears to produce a new type of penicillinase. Penicillinase activity was detected in crude extracts and had a specific activity of 0.25 U/mg of protein. About 20% of the enzyme was released into the surrounding medium during growth. The enzyme hydrolyzed ampicillin and cloxacillin more rapidly than it did penicillin G, carbenicillin, and cephaloridine. Relative rates in a crude extract with penicillin G as 100 were ampicillin, 357; carbenicillin, 57; cloxacillin, 271; and cephaloridine, 71. Enzyme activity was inhibited by clavulanic acid, CP-45, 899, N-formimidoyl thienamycin, cefoxitin, moxalactam, and p-chloromercuribenzoate. The enzyme had a molecular weight of approximately 41,500 and an isoelectric point of 6.9. Penicillinase production and tetracycline resistance were transferred from B.fragilis GN11499 to two susceptible strains of B.fragilis and Bacteroides vulgatus by filter mating.
在80株脆弱拟杆菌属临床分离菌株中发现了一株对青霉素高度耐药的脆弱拟杆菌菌株GN11499，它似乎能产生一种新型青霉素酶。在粗提物中检测到了青霉素酶活性，其比活性为0.25 U/mg蛋白质。在生长过程中，约20%的酶释放到周围培养基中。该酶水解氨苄西林和氯唑西林的速度比水解青霉素G、羧苄西林和头孢菌素的速度更快。以青霉素G为100时，粗提物中的相对水解速率分别为：氨苄西林357、羧苄西林57、氯唑西林271、头孢菌素71。棒酸、CP-45899、N-甲酰亚胺基硫霉素、头孢西丁、莫拉酰胺和对氯汞苯甲酸能抑制该酶的活性。该酶的分子量约为41500，等电点为6.9。通过滤膜交配，青霉素酶产生和四环素耐药性从脆弱拟杆菌GN11499转移到了两株敏感的脆弱拟杆菌和普通拟杆菌菌株。
