耐氨曲南阴沟杆菌β—内酰胺酶性质的初步研究  

Preliminary Studies on β-Lactomases from Aztreonam-Resistant Enterobacter Cloacae

作　　者：黎世能[1] 王浴生[1] 雷军[1] 

机构地区：[1]华西医科大学药理教研室

出　　处：《四川生理科学杂志》1994年第4期6-11,共6页Sichuan Journal of Physiological Sciences

摘　　要：选用4株β—内酰胺酶明显升高的耐氨曲南(最低抑菌浓度≥50mg.L^(-1))阴沟杆菌。采用紫外分光光度计与超薄层等电聚焦电泳技术,对4株耐药菌的β—内酰胺酶从水解底物轮廓,对酶抑制剂敏感性及等电点三方面进行分析。结果表明,4株耐药菌提取的β—内酰胺酶性质均不相同,耐药菌R1029和R855的β—内酰胺酶性质类似于染色体介导的Richmond&Sykes分类中Ⅰ型酶;而R430提取的β—内酰胺酶性质类似于质粒介导的Richmond&Sykes分类中Ⅱ型酶;R875则含有两种不同类型的β—内酰胺酶,等电聚焦图谱上出现等电点不同的两条色带。由于酶性质的不同,在耐药中所起的作用也不同,本文对细菌耐氨曲南机制进行了初步的探讨。The β-Lactamases from 4 strains of Aztreonam(AZ)-resistant Enterobacter cloacae (RAZ) (MIC ≥SOμg/ml) producing high levels of β-Lactamase were studied in hydrolysis substrate profile,susceptibility to β-Lactamase inhibitors and isoelectric point (PI) by using ultraviolet spectrophotometry and superthin layer isoelectric focusing electrophoresis. The results showed that: (1) The β- Lactamases from RAZ 1029 and 855 hydrolyzed cephalosporins stronglier than penicillins, could be inhibited by cloxacillin (MCIPC) or Az,but not by CP45899,PI>8. 0, suggesting that the enzymes probably belonged to chromosome mediated Richmond and Sykes type I β-Lactamase(e. g. P99) ;(2)The β-Lactamase from RAz430 hydrolyzed penicillins and . cephalosporins equally, could be inhibited by either MCIPC or CP45899,but not by Az.PI is the same as TEM -1 (5. 5) .suggesting that the enzyme probably belonged to plasmid-mediated Richmond and Sykes type III β-Lactamase(e. g. TEM -1) ;(3)The β- Lactamase from RAz 857 hydrolyzed cephalosporins and penicillins equally .could not be inhibited by a single inhibitor,but could be inhibited by the combination of CP45899 and MCIPC or CP45899 and Az, presented two bands (PI 8. 6 and 5. 5) on the isoelectrie focusing ekctrophoresis pattern, suggesting that RAz875 had two types of β- Lactamase.

关 键 词：氨曲南 β—内酰胺酶 细菌耐药性 阴沟杆菌 

分 类 号：R378[医药卫生—病原生物学]