2017年临床分离阴沟肠杆菌的耐药性及其ESBLs基因研究

Characterization of drug resistance and ESBLs genes detection in clinical isolates of Enterobacter cloacae in 2017

目的探讨某三级甲等医院2017年临床分离阴沟肠杆菌对抗菌药物的耐药性及其超广谱β-内酰胺酶(extended spectrum beta-lactamases,ESBLs)基因的产生情况。方法收集2017年1月-2017年12月自临床患者分离的159株(非重复菌株)阴沟肠杆菌。菌株鉴定及药敏试验采用Walkway 96全自动细菌鉴定及药敏仪,K-B法补充部分药敏试验。ESBLs表型检测采用双纸片扩散法,降落聚合酶链反应(PCR)检测4种ESBLs基因(blaOXA-1、blaCTX-M、blaTEM、blaSHV)。结果未检出对亚胺培南和美罗培南耐药的阴沟肠杆菌,菌株对其他抗菌药物的耐药率均<30%;38株(23.9%)阴沟肠杆菌ESBLs表型试验阳性,其中,35株携带ESBLs基因,以CTX-M-3型(28/35)为主;产酶(ESBLs)菌株对多数β-内酰胺类抗菌药物的耐药现象较严峻。结论ESBLs表型检测可作为阴沟肠杆菌产ESBLs与否的筛选试验;降落PCR用于ESBLs基因检测简便、快捷;本地区阴沟肠杆菌对抗菌药物的耐药率略低,但产酶菌株耐药现象较严峻,临床医师应根据药敏试验结果合理选择抗菌药物,以减少耐药菌株的产生。

OBJECTIVE To investigate the drug resistance and ESBLs(extended spectrum beta-lactamase)genes of Enterobacter cloacae clinical isolates in a Grade III Class A haspital in 2017.METHODS Totally 159 non-duplicate strains of E.cloacae isolated from clinical patients from Jan.2017 to Dec.2017 were collected.The identification and drug susceptibility test of strains were performed by using Walkway 96 automatic systems,and K-B method was used as a supplementary for drug susceptibility test.Disk diffusion phenotypic confirmatory test were used to detect ESBLs.Four genes encoding ESBLs(blaOXA-1,blaCTX-M,blaTEM,blaSHV)were detected by using touchdown PCR(T-PCR).RESULTS No imipenem and meropenem-resistant E.cloacae were found in this study.The rates of resistance to other antibiotics were all below 30%.38(23.9%)isolates of E.cloacae were positive with ESBLs by using disk diffusion phenotypic confirmatory test.35 isolates carried ESBLs genes,and the main type was CTX-M-3(28/35).ESBLs producers showed high resistance to most beta-lactam antibiotics.CONCLUSION The ESBLs phenotype test could be used for screening of ESBLs production in E.cloacae.T-PCR was a simple and convenient method for detecting ESBLs genes.The rates of antibiotics resistance in this area were relatively low,but there was serious drug resistance in isolates producing ESBLs.Clinicians should rationally select antibiotics according to the results of drug sensitivity test,in order to reduce the occurrence of drug-resistant strains.