致泻性大肠埃希菌的分布及耐药特点研究

Prevalence and antimicrobial resistance of diarrheagenic Escherichia coli

目的监测致泻性大肠埃希菌(diarrheagenic Escherichia coli,DEC)的分布特点及耐药趋势,为流行病学研究、疫苗制备及合理使用抗生素提供依据。方法收集2002—2010年我院肠道门诊腹泻患者的大便标本,沙门-志贺菌培养基培养,筛出可疑菌落后经生化及血清学试验进一步鉴定血清型,用纸片扩散法测定抗菌药物的灵敏性。结果共分离肠道病原菌2104株,其中DEC 118株(5.61%),包括致病性大肠埃希菌(enteropathogenic E.coli,EPEC)78株(66.10%),侵袭性大肠埃希菌(enteroinvasive E.coli,EIEC)29株(24.58%),产毒性大肠埃希菌(enterotoxigenic E.coli,ETEC)11株(9.32%)。患者以男性为主,共76例(64.41%),青、中年组与儿童组无明显差异,5—9月为DEC腹泻发病高峰期。DEC在腹泻菌中比例逐年增加,构成比从2002年的0.21%上升到2010年的18.10%。DEC对氨苄西林、哌拉西林、复方磺胺甲噁唑、环丙沙星和诺氟沙星的耐药率较高,均在45%以上。多重耐药率EPEC高达69.23%、ETEC为45.45%,EIEC为37.93%。结论 DEC引起的感染性腹泻逐年增多,耐药率较高,应重视监测。

Objective To monitor the prevalence and antimicrobial resistance of diarrheagenic Escherichia coli （DEC）, so as to provide evidence for epidemiological study, vaccine preparation and rational use of antibiotics in clinical practice. Methods Stool samples of diarrheal patients treated in our hospital from 2002 to 2010 were collected and cultured for E. coli on Salmonella-Shigella agar. Bacterial colonies were examined by biochemical and serologic methods for the detection of the serotypes and the susceptibility of bacteria to antimicrobial agents was tested by the Kirby-Bauer disk diffusion method. Results Of 2104 intestinal pathogen strains, the prevalance of DEC was 5.61% （118 of 2104）, including enteropathogenic E. coli （EPEC） （66.10%）, enteroinvasive E. coli （EIEC） （24.58%） and enterotoxigenic E. coli （ETEC） （9.32%）. Males accounted for the largest proportion of the patients with diarrhea （64.41%）. The difference between the young and middle-aged groups was not significant. The prevalence of DEC was high from May to September every year. The frequency of DEC was increasing in diarrheal pathogens from 0.21% in 2002 to 18.10% in 2010. DEC exhibited higher frequencies of resistance to ampicillin, piperacillin, compound sulfamethoxazole, ciprofloxacin and norfloxacin （over 45%） and multiple antibiotic resistance rate was 69.23% in EPEC, 45.45% in ETEC and 37.93% in EIEC. Conclusions Infectious diarrhea caused by DEC is increasing with high antimicrobial resistance, so surveillence should be paid much attention.