尿路感染ESBLs阳性大肠埃希菌的基因分型与耐药性分析

摘要

目的 了解尿路感染ESBLs阳性大肠埃希菌的耐药和基因分型遗传特征,指导尿路感染的临床用药与控制医院感染.方法 选取中国中医研究院望京医院2006～2010年医院分离的76株尿路感染大肠埃希菌,通过药敏试验分析这些菌株对17种抗生素的耐药性,用rep-PCR对菌株进行分型.结果 选取的76株尿路感染大肠埃希菌对哌拉西林、庆大霉素、左氧氟沙星、头孢唑啉、头孢呋辛、氨苄西林/舒巴坦、头孢噻肟与头孢曲松的耐药率高达40％以上,依次是86％,68％,64％,59％,59％,41％,41％和40％.17种抗菌药物中,亚胺培南与美洛培南的耐药率最低,敏感率为100％,与ESBLs阴性的大肠埃希菌相比,尿路感染ESBLs阳性大肠埃希菌有14种抗菌药物的耐药率高.76株尿路感染大肠埃希菌分为三个大的组,其中A组敏感性最高,B组次之,C组耐药性最强,含有ESBLs的尿路感染大肠埃希菌主要分布在C组和B组.rep-PCR可以把76株茵分为68个基因型,四个组,分别为Ⅰ,Ⅱ,Ⅲ和Ⅳ,分别包含25,14,20和17株细菌.不同基因型的菌株在耐药性上没有显著差异.结论 尿路感染大肠埃希菌对常见的抗生素产生不同程度的耐药性,含有ESBLs的尿路感染大肠埃希菌的耐药性更高,这些菌株的耐药性可能是通过水平转移获得的.临床上应严格按照科学的用药方案进行抗生素使用,及时掌控ESBLs的尿路致病性大肠埃希菌对抗生素耐药的变化,以减少耐药性菌株的产生,降低耐药菌的危害.%Objective To characterize the antibiotics resistance profiles and genotypes of ESBLs positive uropathogenic Esche-richia coli,and guide clinical antibiotics use. Methods A total of 76 uropathogenic Escherichia coli strains isolated from Wangjing Hospital during 2006~2010 were selected for antibiotics resistance and rep-PCR genotyping. Results The resistance percent for piperacillin,gentamicin,levofloxacm,cefazolin,cefuroxime,ampicillin/sulbactarn,cefotaxime and ceftriaxone were 86% ,68% ,64% ,59% ,59% ,41% ,41% and 40% respectively. All the strains were 100% sensitive for Imipenem and Meropenem. ESBLs positive strains showed higher resistance to 14 of the 17 antibiotics. According to the resistance profiles, the 76 strains were divided into three groups, A,B and Cof which group A showed the highest resistance,followed by B and C. ESBLs positive strains were classified mainly in group C and B. All the 76 strains were genotyped into 68 genotypes and four groups, Ⅰ,Ⅱ , Ⅲ and Ⅳ, which contained 25,14,20 and 27 strains respectively. No significant resistance difference were observed in these genotypes. Conclusion UPEC are resistant to commonly used antibiotics. ESBLs positive isolates showed higher resistance than negative ones. The resistance' might be mainly acquired by horizontal gene transfer. Strict adherence to antibiotics use rules and timely grasp the distribution of ESBLs positive UPEC are important means for prevention of resistant strains.