非O1/非O139群霍乱弧菌感染病例分离株分子流行病学分析

摘要

目的分析安徽省马鞍山市连续2个月内监测到的6例具有霍乱疑似症状、感染非O1/非O139群霍乱弧菌的病例,判断疫情的聚集性.方法 对病例分离株进行生化和血清型别鉴定以及溶血试验,药敏试验检测抗生素耐药谱,应用荧光PCR和常规PCR进行霍乱弧菌特异基因、毒力及其相关基因的检测,包括ompW、ctx 、tcpA、toxR、hlyA 、zot、ace、rstR和gⅢCTX,应用脉冲场凝胶电泳(PFGE)分析其分子型别.结果 生化鉴定和血清学试验鉴别腹泻病例6株菌株为非O1/非O139霍乱弧菌,均产生β溶血；14种药物中有12种属于全部敏感；荧光PCR检测霍乱弧菌特异性基因ompW均为阳性,ctx、tcpA 、zot、ace、rstR和gⅢCTX基因均为阴性,toxR 、hlyA基因有5株菌扩增阳性,1株菌(1001434446)为阴性；PFGE显示6株菌带型均不相同,但有2株非常相似,分离株与霍乱弧菌产毒株相似性很低.结论 6例感染非产毒的非O1/非O139群霍乱弧菌病例发病虽相对集中,但属于散发病例,在局部地区频繁出现,提示其公共卫生意义不可忽视.%Objective According to results from the two-month consecutive surveillance program in Maanshan,six suspected cases of non-O1 non-O139 Vibrio (V.) cholerae infection,were found that called for identification of pathogens as well as molecular-epidemiological analysis to determine the aggregation of the epidemic situation.Methods Biochemical and serotype identification,hemolysis test,and drug sensitive test were used to detect the drug resistance spectrum.Real-time PCR and conventional PCR were used to detect the presence of V.cholerae specific genes,virulent genes and its related genes,including ompW,ctx,tcpA,toxR,hlyA,zot,ace,rstR and g ⅢCTX.Pulsed-field gel electrophoresis (PFGE) was used to analyze the molecular type of strains.Results All the six isolates of non-O 1 non-O 139 V.cholerae were identified by biochemical and serologic tests,and appeared to be β hemolytic.Twelve out of the 14 kinds of drugs showed 100％ sensitive.All isolates were positive of ompW gene by real-time PCR,but negative for ctx,tcpA,zot,ace,rstR and gⅢ CTK.Five of the six isolates were positive for toxR and hlyA,except for strain 1001434446.All strains had different PFGE types,but two strains had similar types.All strains had a low similarity compared to the toxigenic V.cholerae.Conclusion Six cases ofnon-O1 and non-O139 nontoxigenic V.cholerae infection appeared in the same period.Along with epide(m)iological information,we noticed that these cases had a sporadic nature,but frequently appeared in the same area.We got the impression that public health measurements should be strengthened,with special attention paid to those diarrhea outbreaks caused by non-O 1 on-O 139 strains since V.cholerae had appeared in low incidence.