耐氨曲南阴沟肠杆菌β－内酰胺酶性质的初步研究  

Preliminary studies on β-lactamases from aztreonam-resistant En terobacter 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,成都中医学院附属医院临床药理研究室

出　　处：《中国药理学与毒理学杂志》1994年第4期297-300,共4页Chinese Journal of Pharmacology and Toxicology

摘　　要：选用４株β－内酰胺酶明显升高的耐氨曲南（最低抑菌进度≥５０ｍｇ·Ｌ－１）阴沟肠杆菌，以紫外分光光度计与超薄层等电聚焦电泳技术，对β－内酰胺酶从水解底物轮廓，酶抑制剂敏感性及等电点三方面进行了分析．结果表明，从４株耐药菌提取的β－内酰胺酶的性质不尽相同，耐药菌Ｒ１０２９和Ｒ８５５的β－内酰胺酶类似于染色体介导的ＲｉＣｈｍｏｎｄ＆Ｓｖｋｅｓ分类中Ⅰ型酶：Ｒ４３０的β－内酰胺酶类似于质粒介导的Ｒｉｃｈｍｏｎｄ＆Ｓｙｋｅｓ分类中Ⅲ型酶；而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．在耐药性中所起的作用也不同．本文对细菌耐氨曲南机理进行了初步的探讨．The high level plactamases producing from 4 strains of aztreonam (Azt)-resistant en-terobacter ctoacae tRAzt, minimal inhibitory concentration≥ 50 mg· L-1 were studied in substratehydrolysis profile, susceptibility to β-lactamaseinhibitors and isoelectric point (pI) by using ultravioletspectrophotometry and superthin layer isoelectric fo-cusing electrophoresis. The results showed that theβ-lactamases from RAzt 1029 and 855 hydrolyzedcephalosporins more strongly than penicillins, could beinhibited by cloxacillin (MCIPC) or Azt. but not byCP45899, pI > 8.0. It suggested that the enzyme proba-bly belonged to chromosome-mediated Richmond andSykes type I β-lactamase (e.g. P99). The plactamasefrom RAzt 430 hydrolyzed penicillins andcephalosporins equally, could be inhibited by eitherMCIPC or CP45899, but not by Azt, PI is the same asTEM-1 (5.5). It suggested that the enzyme probablybelonged to plasmidmediated Richmond and Sykestype Ⅲ β-lactamase (e.g. TEM-I). The β-lactamasefrom RAzt 875 hydrolyzed cephalosponns andpenicillins equally, could only be inhibited by the com-bination (instead of their any single use) of CP45899and MCIPC or CP45899 and Azt, which presented twobands (pI 8.6 and 5.5) on the isoelectric focusingelectrophoresis pattern. It suggested that RAzt 875 hadtwo types of plactamases.

关 键 词：内酰胺酶 抗药性 肠杆菌属 氨曲南 

分 类 号：R978.11[医药卫生—药品]