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目的了解昌平区肠集聚性黏附大肠埃希氏菌(EAEC)耐药性、毒力基因携带情况及分子特征。方法对2012—2016年北京市昌平区分离的15株EAEC毒株进行复核;以药敏实验检测菌株对16种抗菌药物的耐药性;以PCR法检测8种毒力的携带情况;采用多位点序列分型(MLST)及脉冲场凝胶电泳分型(PFGE)进行分子分型分析。结果 15株EAEC耐药率为100.0%,耐多药率为80.0%。每株携带2~5个毒力基因,共有10种毒力基因谱;8个毒力基因阳性率由高到低分别为aap(100.0%)、CVD432(93.3%)、aggA(60.0%)、agg3A(40.0%)、astA(33.3%)、pic(20.0%)、aafA(13.3%),未检出pet阳性。MLST分型分析将15株EAEC菌分为9个ST型,其中有4个新ST型(STcpEC1、STcpEC2、STcpEC3、STcpEC4),以STcpEC1为优势ST型(占33.3%)。PFGE分析得到13种PFGE带型,相同ST型菌株PFGE带型、毒力基因相似系数均较高。结论北京市昌平区近5年EAEC菌耐药率、多重耐药率较高,毒力基因aap、CVD432、aggA检出率高,STcpEC1为优势ST型,PFGE带型具有高度多态性。
Objective To understand the drug resistance and virulence genes of Intestinal Aggluthering Escherichia coli (EAEC) in Changping District and its molecular characteristics. Methods Fifteen strains of EAEC isolated from Changping district of Beijing were reviewed in 2012-2016. The susceptibility of 16 strains of strains to antibacterials was tested by drug susceptibility test. Eight strains of virulence were detected by PCR. Site sequence typing (MLST) and pulsed-field gel electrophoresis typing (PFGE). Results The resistance rate of 15 EAEC strains was 100.0% and the multidrug resistance rate was 80.0%. There were 10 virulence genes in each strain. The positive rate of the 8 virulence genes was aap (100.0%), CVD432 (93.3%), aggA (60.0%), agg3A (40.0%), astA (33.3%), pic (20.0%) and aafA (13.3%). MLST typing analysis divided 15 EAEC strains into 9 ST types, including 4 new ST types (STcpEC1, STcpEC2, STcpEC3, STcpEC4) and STcpEC1 ST (33.3%). Thirteen PFGE bands were obtained by PFGE analysis, and the PFGE bands of the same ST strains showed higher similarity coefficients of virulence genes. Conclusion The prevalence of multidrug resistance and multidrug resistance in EAEC strains in Changping District of Beijing during the recent 5 years was high. The detection rates of aap, CVD432 and aggA genes were high, and STcpEC1 was predominant ST. PFGE bands were highly polymorphic.