【摘要】 近年国外报道许多对第三代头孢菌素耐药的细菌是由于产生新的β－内酰胺酶所致。为探讨耐头孢哌酮的Ｅ．ｃｏｌｉＨＸ８８１０８及其４株转化菌ｐＦＣ、ｐＦＴ１、ｐＦＴ２、ｐＦＴ３的β－内酰胺酶性质，进行了β－内酰胺酶底物轮廓测定，酶抑制剂棒酸和舒巴坦敏感性研究以及薄层分析性等电聚焦电泳。结果显示：Ｅ．ｃｏｌｉＨＸ８８１０８及转化菌ｐＦＣ、ｐＦＴ１酶能有效水解第三代头孢菌素的头孢哌酮，对青霉素及第一、二代头孢菌素有较强的水解作用；ｐＦＴ２和ｐＦＴ３酶对青霉素类水解作用较强，对头孢菌素水解作用较弱；酶抑制剂对ＨＸ８８１０８、ｐＦＴ１、ｐＦＴ２和ｐＦＴ３的酶抑制作用强，而对ｐＦＣ酶抑制作用较弱。Ｅ．ｃｏｌｉＨＸ８８１０８含有三个不同等电点的β－内酰胺酶，ＰＩ分别为５．２５、５．３和５．６。为此，我们推测Ｅ．ｃｏｌｉＨＸ８８１０８质粒编码的β－内酰胺酶可能系ＴＥＭ家族新成员。更多还原

【Abstract】 E.coli HX88108 was isolated from a patient and found to produce plasmidencode βlactamases with conferring highly resistance to ceforperazone(CPZ). The βlactamases of the E.coli HX88108 and transformants pFC, pFT1,pFT2 and pFT3 were studied. The βlactamases stability test among 11 βlactam antibiotics showed that βlactamases from E.coli HX88108. pFC, pFT1, readily hydrolyzed penicillins, the first, secondgeneration cephalosporins and CPZ. βlactamases of pFT2 and pFT3 hydrolyzed penicillins more strongly than cephalosporins. On the other hand, experiments of inhibiting enzyme were carried out. The results indicated that βlactamases of HX88108, pTF1,pFT2 and pFT3 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 βlactamases, of which the PIs were 5.25,5,3 and 5.6 respectively; the PIs of βlactamases from pFT2, pFT3,were 5.3 and 5.6. pFC and pFT1 were different plasmids encoded βlactamases with the same PI 5.25. The results indicate that the βlactamases of E.coli HX88108 may be a new member in TEM farmily.更多还原