Zhou L, Bao D, Fan X, Liu B
Department of Pharmacology, School of Basic Medical Sciences, Chengdu.
Hua Xi Yi Ke Da Xue Xue Bao. 1998 Mar;29(1):11-5.
E. coli HX88108 was isolated from a patient and found to produce plasmid-encode beta-lactamases with conferring highly resistance to ceforperazone(CPZ). The beta-lactamases of the E. coli HX88108 and transformants pFC, pFT1, pFT2 and pFT3 were studied. The beta-lactamases stability test among 11 beta-lactam antibiotics showed that beta-lactamases from E. coli HX88108. pFC, pFT1, readily hydrolyzed penicillins, the first, second-generation cephalosporins and CPZ. beta-lactamases of pFT2 and pFT3 hydrolyzed penicillins more strongly than cephalosporins. On the other hand, experiments of inhibiting enzyme were carried out. The results indicated that beta-lactamases of HX88108, pTF1, pFT2 and pFT3 were inhibited by clavulanic acid(CA) and sulbactam (SBT). Enzyme of pFC was inhibited poorly by CA and SBT. Through isoelectric focusing technique, the PIs were as follows: HX88108 contained three beta-lactamases, of which the PIs were 5.25, 5.3 and 5.6 respectively; the PIs of beta-lactamases from pFT2, pFT3, were 5.3 and 5.6. pFC and pFT1 were different plasmids encoded beta-lactamases with the same PI 5.25. The results indicate that the beta-lactamases of E. coli HX88108 may be a new member in TEM farmily.
大肠杆菌HX88108从一名患者体内分离得到，发现其产生由质粒编码的β-内酰胺酶，该酶赋予对头孢哌酮（CPZ）高度耐药性。对大肠杆菌HX88108以及转化体pFC、pFT1、pFT2和pFT3的β-内酰胺酶进行了研究。在11种β-内酰胺类抗生素中进行的β-内酰胺酶稳定性试验表明，来自大肠杆菌HX88108、pFC、pFT1的β-内酰胺酶能迅速水解青霉素、第一代、第二代头孢菌素和CPZ。pFT2和pFT3的β-内酰胺酶对青霉素的水解作用比对头孢菌素更强。另一方面，进行了酶抑制实验。结果表明，HX88108、pTF1、pFT2和pFT3的β-内酰胺酶可被克拉维酸（CA）和舒巴坦（SBT）抑制。pFC的酶受CA和SBT的抑制作用较弱。通过等电聚焦技术，等电点如下：HX88108含有三种β-内酰胺酶，其等电点分别为5.25、5.3和5.6；pFT2、pFT3的β-内酰胺酶的等电点为5.3和5.6。pFC和pFT1是不同质粒编码的β-内酰胺酶，等电点相同，均为5.25。结果表明，大肠杆菌HX88108的β-内酰胺酶可能是TEM家族的一个新成员。
