上海市宝山区2015—2018年腹泻病人沙门菌血清分型和分子分型

目的 揭示上海市宝山区腹泻病人分离沙门菌的血清型和分子分型分布特征。方法 对2015—2018年分离的118株沙门菌进行血清分型和脉冲场凝胶电泳（pulsed-field gel electrophoresis,PFGE）分型,通过构建聚类树揭示不同血清型菌株的分子分型特征。结果 118株沙门菌分为25种血清型,前三位为肠炎沙门菌（45株,38.1%）、鼠伤寒沙门菌（26株,22.0%）、伦敦沙门菌（11株,9.3%）。其余22种血清型分别只包含1~3株菌。118株沙门菌通过PFGE分为71个PFGE带型,每个带型分别包含1~19株菌。45株肠炎沙门菌分为8个PFGE带型,相似度为75.0%~100.0%,在聚类树上形成一个簇;26株鼠伤寒沙门菌分为21个PFGE带型,相似度为48.0%~100.0%,在聚类树上形成两个簇;11株伦敦沙门菌分为8个PFGE带型,相似度为80.0%~100.0%,在聚类树上形成一个簇。结论 肠炎沙门菌和鼠伤寒沙门菌是上海市宝山区腹泻病人沙门菌优势血清型,但近年伦敦沙门菌有增多的趋势。肠炎沙门菌在本地区传播流行过程中的遗传变异相对比较保守,鼠伤寒沙门菌基因型多态性大,而且存在两个克隆。

Serotyping and molecular subtyping of Salmonella isolated from diarrhea patients in Baoshan District,Shanghai, 2015-2018

Objective To reveal the distribution characteristics of serotypes and molecular typing of Salmonella isolated from diarrhea patients in Baoshan District of Shanghai. Methods Serotyping and pulsed-field gel electrophoresis (PFGE) of 118 Salmonella strains isolated between 2015 and 2018 were carried out, and molecular subtyping characteristics of different serotypes were revealed by constructing cluster tree. Results One hundred and eighteen Salmonella strains were divided into 25 serotypes. The top three were Salmonella enteritidis (45 strains, 38.1%), Salmonella typhimurium (26 strains, 22.0%) and Salmonella london (11 strains, 9.3%). The remaining 22 serotypes contained only 1-3 strains respectively. One hundred and eighteen Salmonella strains were divided into 71 PFGE types, and each type contained 1-19 strains respectively. Forty-five strains of S. enteritidis were divided into eight PFGE types with similarity of 75.0%-100.0%, forming a cluster on the cluster tree; 26 strains of S. typhimurium were divided into 21 PFGE types with similarity of 48.0%-100.0%, forming two clusters on the cluster tree; 11 strains of S. london were divided into eight PFGE types with similarity of 80.0%-100.0%, forming one cluster on the cluster tree. Conclusion S. enteritidis and S. typhimurium are the predominant serotypes of Salmonella in diarrhea patients in Baoshan District of Shanghai, but in recent years, there is an increasing trend of S. london. The genetic variation of S. enteritidis is relatively conservative during its transmission in this area. The genotype of S. typhimurium is highly polymorphic, and there are two clones.