杭州市2002-2008年甲型副伤寒沙门菌分子分型研究

目的研究2002-2008年杭州市甲型副伤寒疫情分离株的亲缘性,并探讨脉冲场凝胶电泳（PFGE）、多位点序列分型（MLST）在甲型副伤寒沙门菌分子分型中的应用。方法对404株甲型副伤寒沙门菌运用脉冲场凝胶电泳（PFGE）进行分子分型,并用K-B法测定菌株抗生素敏感性。挑选9株甲型副伤寒沙门菌进行多位点序列分型（MLST）以及稳定性试验。结果 404株甲型副伤寒沙门菌可分为6个PFGE型和4个耐药型,P1型和P2型属于同一个克隆系,该克隆系菌株占试验菌株数的99%,分离自临安市的310株菌均为P1型,分离自杭州市西湖区的主要菌型是P2型和P1型。9株甲型副伤寒沙门菌根据SucA位点的差异可分为2个MLST型。结论杭州市2002-2008年的甲型副伤寒疫情由同一克隆系的菌株主导。PFGE、MLST分型方法各有侧重,可互为补充。

Molecular typing of Salmonella paratyphi A isolates,Hangzhou,2002-2008

Objective To study the relationship of Salmonella paratyphi A isolated strains and discuss the applications of pulse field gel electrophoresis（PFGE） and multilocus sequence typing（MLST）on molecular typing of Salmonella paratyphi A strains.Methods 404 Salmonella paratyphi A were strain typed by PFGE and were also determined the antibiotic resistances by disc diffusion test（Kirby-Bauer method） in Hangzhou from 2002-2008.9 strains were randomly selected for MLST assay as well as the stability validation of the PFGE and MLST.Results The Salmonella paratyphi A were divided into 6 PFGE strain types and 4 resistant spectrums.The strains of P1 and P2 belonged to one clone family,which included 99% of the isolated strains.310 strains isolated from Lin′an were P1 and most of the strains isolated from Xihu district were P2 and P1.9 selected strains of Salmonella paratyphi A could be divided into 2 MLST types by SucA site polymorphism.Conclusion The result shows that paratyphoid A epidemic was caused by strains of one clone family in Hangzhou from 2002 to 2008.The application of a combined approach of PFGE and MLST methods focusing on different aspects can complement each other for molecular typing of Salmonella paratyphi A strains.