浙江省临床分离沙门菌血清型、药物敏感性和毒力基因的研究

Study on the serotype,drug sensitivity and virulence genes of clinical isolates of Salmonella in Zhejiang Province

目的研究浙江省临床分离沙门菌的血清型分布、耐药状况和携带毒力基因的特征。方法收集2010年至2017年浙江省9个地区临床分离的463株沙门菌,依据沙门菌属Kauffmann-White抗原表对比确定沙门菌属的血清型。采用K-B纸片扩散法进行药物敏感试验。采用聚合酶链反应检测菌株的11种毒力基因。结果463株沙门菌共检出35种血清型,其中优势血清型为鼠伤寒沙门菌[41.90%(194/463)]和肠炎沙门菌[22.25%(103/463)]。对氨苄西林的耐药率[66.52%(308/463)]最高,其次为氨苄西林/舒巴坦[46.87%(217/463];对哌拉西林/他唑巴坦的耐药率[3.24%(15/463)]较低;无亚胺培南和美罗培南耐药株;多重耐药菌株188株(40.60%)。毒力基因hilA、ssrB、marT、siiD、sopB、pagN在所有沙门菌株中都存在。毒力基因vexA只在伤寒沙门菌和都柏林沙门菌中检出;毒力基因icmF主要存在于肠炎沙门菌中;毒力质粒基因spvB和pefA表现为成对出现,且主要分布于猪霍乱沙门菌、肠炎沙门菌和鼠伤寒沙门菌中;毒力基因cdtB则主要分布于伤寒沙门菌和甲型副伤寒沙门菌中。结论浙江省临床分离的沙门菌以鼠伤寒沙门菌和肠炎沙门菌为主,多重耐药形势严峻,且携带多种毒力基因。

Objective To investigate the serotype distribution,drug resistance and the virulence gene profiles of clinical isolates of Salmonella in Zhejiang Province.Methods A retrospective study of 463 clinical isolates of Salmonella in nine regions of Zhejiang Province from 2010 to 2017 was conducted.Their serotypes were detected using the Kauffmann-White scheme based on serological detection.Antibiotics susceptibility tests were carried out using K-B disk diffusion method.Eleven virulence genes were detected by polymerase chain reaction.Results A total of 35 serotypes were identified among the 463 strains of Salmonella.The dominant serotypes were Salmonella typhimurium(41.90%(194/463))and Salmonella enteritis(22.25%(103/463)).The resistance rate of Salmonella to ampicillin was the highest(66.52%(308/463)),followed by ampicillin/sulbactam(46.87%(217/463)),while low resistance rate to piperacillin/tazobactam was observed(3.24%(15/463)).All strains were sensitive to imipenem and meropenem.Finally,188 strains(40.60%)of multi-drug resistance were found.The virulence genes hilA,ssrB,marT,siiD,sopB and pagN were found in all Salmonella strains.The virulence gene vexA was found only in Salmonella typhi and Salmonella Dublin;virulence gene icmF was mainly found in Salmonella enteritis.The virulence plasmid gene spvB and pefA were mainly found in Salmonella enteritidis and Salmonella typhimurium and invariably appeared in pairs.The virulence gene cdtB was mainly found in Salmonella typhi and Salmonella paratyphi A.Conclusions Salmonella typhimurium and Salmonella enteritis are the main clinically isolated Salmonella strains in Zhejiang Province.The situation of multi-drug resistance is severe and a variety of virulence genes are highly detected.