2019年福建省哨点医院腹泻患者中致泻大肠埃希菌感染状况及病原学特征分析

Infection status and etiological characteristics of diarrheogenic Escherichia coli among diarrhea patients in sentinel hospitals of Fujian Province in 2019

目的了解2019年福建省哨点医院腹泻患者中致泻大肠埃希菌(DEC)感染状况、毒力基因携带、分子分型及耐药情况。方法采集腹泻患者210份粪便标本按照GB 4789.6—2016《食品安全国家标准食品微生物学检验致泻大肠埃希氏菌检验》方法分离大肠埃希菌后进行荧光聚合酶链式反应(PCR)确认,并对分离出的DEC进行脉冲场凝胶电泳(PFGE)分子分型及药敏试验。结果共检出阳性菌株32株,检出率为15.2%(32/210),其中肠道致病性大肠埃希菌(EPEC)占37.5%(12/32),肠道集聚性大肠埃希菌(EAEC)占37.5%(12/32),产肠毒素大肠埃希菌(ETEC)占25.0%(8/32)。药敏试验结果表明,32株菌对氨苄西林耐药程度最高,耐药率为78.1%(25/32),其次是四环素和甲氧苄啶/磺胺甲噁唑,耐药率分别为62.5%(20/32)和59.4%(19/32)。多重耐药(MDR)率为50.0%(16/32)。PFGE结果表明,32株菌共分为28种PFGE带型,其中12株EPEC共分为10种带型,12株EAEC共分为10种带型,8株ETEC共分为8种带型,其中EPEC聚类分析结果有两组菌株具有100.0%相似带型,EAEC有一组菌株具有100.0%相似带型,ETEC聚类分析没有完全一致的带型。结论2019年福建省哨点医院腹泻患者DEC感染主要以EPEC、EAEC为主,菌株分型带型存在多样性,菌株耐药状况严重,且存在较高的多重耐药率。

Objective To investigate the infectious status,virulence gene,molecular typing and antibiotic resistance of diarrheogenic Escherichia coli(DEC)in sentinel hospitals of Fujian Province in 2019.Methods Fluorescent polymerase chain reaction(PCR)was used to identify 210 fecal samples of diarrhea patients after isolation of E.coli according to GB 4789.6-2016,and then pulsed field gel electrophoresis(PFGE)molecular traceability and antibiotic resistance test were conducted on the isolated DEC.Results Thirty two strains of bacteria were detected,with a detection rate of 15.2%(32/210).Among them,enteropathogenic E.coli(EPEC)accounted for 37.5%(12/32),enteroaggregative E.coli(EAEC)for 37.5%(12/32),and enterotoxigenic E.coli(ETEC)for 25.0%(8/32).The results of antibiotic resistance test showed that these 32 strains of bacteria were most resistant to ampicillin,with a resistance rate of 78.1%(25/32),followed by tetracycline and trimethoprim/sulfamethoxazole,with resistance rates of 62.5%(20/32)and 59.4%(19/32),respectively.The multiple antibiotic resistance rate was 50.0%(16/32).The results of PFGE showed that 32 strains of bacteria causing diarrhea were divided into 28 PFGE banding patterns.Among them,12 strains of EPEC and 12 strains of EAEC were divided into 10 PFGE banding patterns,respectively,and 8 strains of ETEC were divided into 8 PFGE banding patterns.The results of cluster analysis showed that two groups of EPEC strains had 100.0%similar banding patterns,one group of EAEC strains had 100.0%similar banding patterns,and ETEC strains did not have completely consistent banding pattern.Conclusion EPEC and EAEC were the main pathogens of diarrhea in surveillance points of Fujian Province in 2019.The genetic diversity of the strains showed that the genetic relationship between them was relatively distant.The antibiotic resistance of DEC was severe,and the rate of multiple antibiotic resistance was high.