2019—2022年上海市奉贤区哨点医院致泻性大肠埃希菌的耐药性和同源性

Drug resistance and homology of diarrheagenic Escherichia coli in sentinel hospital of Fengxian District of Shanghai,2019‒2022

【目的】开展上海市奉贤区的致泻性大肠埃希菌(DEC)耐药性和同源性分析,为临床合理用药和风险监测预警提供依据。【方法】收集2019—2022年上海市奉贤区腹泻病检测中分离到的DEC,采用微量肉汤稀释法进行21种抗生素药物敏感试验,采用脉冲场凝胶电泳(PFGE)进行聚类分型。【结果】腹泻病例DEC检出率为18.99%(131/690)、肠聚集性大肠埃希菌(EAEC)占64.89%(85/131)、肠产毒性大肠埃希菌(ETEC)占22.14%(29/131)、肠致病性大肠埃希菌(EPEC)占12.21%(16/131)、肠出血性大肠埃希菌(EHEC)占0.76%(1/131),未检出肠侵袭性大肠杆菌(EIEC)。DEC检出具有明显夏季高发的季节性特点。DEC多重耐药率为66.41%,共有65种耐药谱,耐药率最高的5种抗生素是氨苄西林(60.31%)、萘啶酸(51.91%)、头孢唑林(50.38%)、四环素(44.27%)、复方新诺明(35.11%),2019—2022年DEC对左氧氟沙星的耐药率明显升高。85株EAEC聚类分析相似度为58.4%~100.0%,得到69种带型;29株ETEC聚类分析相似度为58.5%~100.0%,得到13种带型,有2种优势带型;16株EPEC聚类分析相似度为53.9%~96.0%,得到15种带型。共发现5组同源性菌株,同源性菌株耐药表型均一致。【结论】上海市奉贤区腹泻病例中DEC流行强度较高,耐药形势严峻,引起暴发感染的风险较高,需要加强监测和防范。

[Objective]We conducted a drug resistance and homology analysis of diarrheagenic Escherichia coli(DEC)in Fengxian District of Shanghai in order to provide a basis for clinical rational drug use,risk monitoring and early warning.[Methods]DEC were isolated from diarrheal patients in Fengxian District,Shanghai from 2019 to 2022.The minimum inhibitory concentrations(MIC)of 21 drugs to the DEC were determined.Genotyping and homology analysis were conducted with pulsed-field gel electrophoresis(PFGE).[Results]The DEC detection rate of diarrhea cases was 18.99%(131/690),including enteroaggregative E.coli(EAEC)64.89%(85/131),enterotoxigenic E.coli(ETEC)22.14%(29/131),enteropathogenic E.coli(EPEC)12.21%(16/131),and enterohemorrhagic E.coli(EHEC)0.76%(1/131).The DEC detection showed obvious seasonal characteristics with a high incidence in summer.The DEC multidrug resistance rate was 66.41%with a total of 65 drug resistance profiles.The five antimicrobial drugs with the highest resistance rate were ampicillin(60.31%),nalidixic acid(51.91%),cefazolin(50.38%),tetracycline(44.27%),and cotrimoxazole(35.11%).The rate of DEC resistance to levofloxacin was significantly increased from 2019 to 2022.Cluster analysis showed that the similarity of 85 EAEC cluster was 58.4%‒100.0%,and 69 band patterns were obtained.The similarity of 29 ETEC cluster was 58.5%‒100.0%,and 13 band patterns were obtained,including 2 dominant band types.The similarity of 16 EAEC clusters was 53.9%‒100.0%,and 15 band patterns were obtained.Five groups of homologous strains were found,consistent with the resistance phenotypes.[Conclusion]Among the diarrhea cases,the DEC epidemic intensity is high,the drug resistance situation is severe,and the risk of outbreak infection is high in Fengxian District,Shanghai.Therefore,health monitoring and prevention need to be strengthened.