2002—2013年杭州地区甲型副伤寒沙门菌分子分型研究

摘要

目的 了解近年来杭州地区甲型副伤寒沙门菌的分子特征.方法 采用脉冲场凝胶电泳(PFGE)、多位点串联重复序列分析(MLVA)对2002—2013年杭州地区分离的72株甲型副伤寒沙门菌代表株进行分子分型及流行病学分析.结果 72株甲型副伤寒沙门菌分为11个PFGE(XbaⅠ、BlnⅠ)型别,6个MLVA型别.受检的34个可变串联重复序列(VNTR)位点中,1188K、2075K、2201K、4346K这4个位点表现出多态性.PFGE显示出较MLVA更高的分辨力.除X4B5、X7B7、X8B8、X9B9、X10B10这5种型别外,其他6种型别为同一个克隆系(相似度大于95%),该克隆系菌株占受试总菌株数的93.1%.结论 2002—2013年杭州地区甲型副伤寒疫情主要由同一克隆系的菌株引起,联合应用PFGE和MLVA有利于甲型副伤寒的流行病学调查.%Objective To analyze the molecular characteristics of Salmonella paratyphi A ( S. pa-ratyphi A) strains prevailing in Hangzhou area in recent years. Methods Pulse field gel electrophoresis ( PFGE) and multiple-locus variable-number tandem repeat analysis ( MLVA) were performed for molecular typing and epidemiological analysis of 72 S. paratyphi A strains isolated in Hangzhou area during 2002 to 2013. Results The 72 S. paratyphi A strains were divided into 11 PFGE ( by using restriction enzymes of Xba Ⅰ and Bln Ⅰ) and 6 MLVA types. Among the selected 34 variable number tandem repeat ( VNTR) sites, 4 sites (1188K, 2075K, 2201K and 4346K) showed high polymorphism, in which PFGE displayed a higher resolution than MLVA. Except for the 5 PFGE types of X4B5, X7B7, X8B8, X9B9 and X10B10, the other 6 PFGE types belonged to a same clone sharing a similarity of greater than 95%, and the S. Paratyphi A strains in that clone accounted for 93. 1% of the total strains isolated in Hangzhou. Conclu-sion The occurrence of paratyphoid A in Hangzhou area from 2002 to 2013 was mainly caused by S. para-typhi A strains belonging to the same clone. Combination of PFGE with MLVA was conducive to epidemiolog-ical investigation of paratyphoid A.