107株阴沟肠杆菌产ESBLs和AmpC酶检测及耐药性分析

Detection of ESBLs and AmpC β-lactamase in 107 strains of Enterobacter cloacae and analysis of their drug resistance

目的了解近年来临床分离的阴沟肠杆菌对常用抗菌药物的敏感性,并检测分离株产超广谱β-内酰胺酶(ESBLs)和Amp C酶的情况,指导临床合理用药。方法收集2016年1-12月湖南中医药大学第一附属医院分离自临床标本的阴沟肠杆菌,采用Vitek-2 Compact进行常规药敏试验,采用表型确证试验检测ESBLs,采用三维试验检测Amp C酶。结果共收集非重复分离阴沟肠杆菌107株,主要来源于呼吸内科(26/107,24.3%)、骨伤科(21/107,19.6%)、中心ICU(20/107,18.7%)等科室,以痰液(38/107,35.5%)和伤口分泌物(29/107,27.1%)等标本为主;阴沟肠杆菌对青霉素类、三代头孢菌素和头霉素类高度耐药,对哌拉西林/他唑巴坦、头孢吡肟、亚胺培南耐药率分别为13.1%、22.4%、0.9%。共检测出单产ESBLs菌株30株(28.0%),单产Amp C酶的菌株35株(32.7%);同时产ESBLs和Amp C酶菌株14株(13.1%);同时产ESBLs和Amp C酶菌株对常用抗菌药物的耐药率高于不产酶株,差异均有统计学意义(均P<0.05)。结论产ESBLs、Amp C酶是阴沟肠杆菌多重耐药的重要机制;阴沟肠杆菌产酶株的检测,对指导临床抗菌治疗具有重要意义。

Objective To investigate the susceptibility to commonly-used antimicrobial agents in clinically isolated Enterobacter cloacae in recent years, to determine the prevalence of isolates producing extened spectrum β-lactamases （ESBLs） and cephalosporinase （AmpC）, and to provide reference for reasonable use of antibiotics in clinical practice. Methods We collected Enterobacter cloacae strains isolated from clinical specimens in the First Hospital of Hunan University of Chinese Medicine from January to November in 2016. The routine antibiotic susceptibility tests were conducted by Vitek-2 Compact fully automatic bacterial identification and drug susceptibility analyzer. ESBLs and AmpC were determined respectively by phenotypic confirmatory test and three dimensional test. Results A total of 107 non-repeatedly isolated Enterobacter cloacae strains were collected mainly from respiratory medicine department （26/107, 24.3%）, bone traumatology department （21/107, 19.6%） and central ICU （20/107, 18.7%）. The main specimens were sputum （38/107, 35.5%） and wound secretion （29/107, 27.1%）. Enterobacter cloacae strains were highly resistant to penicillin, third-generation cephalosporins and cephamycins. The drug resistance rates to piperacillin/tazobactam, cefepime and imipenem were 13.1%, 22.4% and 0.9% respectively. 30 （28.0%） strains produced ESBLs, 35 （32.7%） strains AmpC, and 14 （13.1%） stains ESBLs and AmpC parallelly. The rates of resistance to commonly-used antimicrobial agents were higher in the stains produced both ESBLs and AmpC enzyme than in the non-enzyme-producing stains. Conclusions Producing ESBLs and AmpC enzyme acts the important mechanism to multidurg resistance of Enterobacter cloacae; and hence, it is of great value to detect enzyme-producing isolates for antibiotic therapy.