Molecular typing and surveillance on Salmonella typhimurium strain in Guangdong province, 2009-2011
10.3760/cma.j.issn.0254-6450.2014.08.010
- VernacularTitle:广东省2009-2011年鼠伤寒沙门菌监测及菌株分子分型的研究
- Author:
Yanhui HUANG
1
,
2
;
Bixia KE
;
Jiufeng SUN
;
Dongmei HE
;
Qing CHEN
;
Changwen KE
;
Shouyi YU
Author Information
1. 510515广州,南方医科大学公共卫生与热带医学学院流行病学系
2. 深圳市宝安区慢性病防治院皮肤性病防治科
- Keywords:
Salmonella typhimurium;
Enhance Salmonella Surveillance;
Molecular typing
- From:
Chinese Journal of Epidemiology
2014;35(8):917-924
- CountryChina
- Language:Chinese
-
Abstract:
Objective To understand the distribution and the characteristics on molecular typing of Salmonella (S.) typhimurium isolates gathered from the surveillance program and to construct the standard S.typhimurium databank in the laboratory through surveillance network PulseNet,in Guangdong province to improve the capability of detection on laboratory-based foodbome outbreaks.Methods With the application of standard pulse-field gel electrophoresis (PFGE) and multiple loci VNTR analysis (MLVA) including seven VNTRs loci protocols on PulseNet International Network,275 isolates of S.typhimurium from ten cities in Guangdong province were typed and their patterns analyzed.The molecular typing databank was constructed by BioNumerics.Results With S.typhimurium the most common serotypes,the average annual positive rate of Salmonella strains and S.typhimurium were 4.03％ and 1.38％ respectively.The positive rate and proportion presented a double-peak trend,appearing in May and September.The chromosomal DNA of S.typhimurium was digested with Xba Ⅰ restricted endonucleotidase and 124 PFGE patterns were observed after pulse-field gel electrophoresis,with the discrimination index (D) as 0.928 6.The patterns including more than three S.typhimurium isolates and were further digested with the second enzyme Bln Ⅰ to achieve 174 patterns,with the D value as 0.989 1.Under MLVA method,143 variant patterns were obtained,with the D value reaching 0.966 5.Data showed that the discriminatory ability of the MLVA typing method in S.typhimurium was superior to PFGE-Xba Ⅰ but equal to PFGE-Xba Ⅰ-Bln Ⅰ.In addition,when S.typhimurium strains were respectively analyzed by PFGE under double enzymes digestion and MLVA,the results appeared coincident and relative.Conclusion The variant patterns showed by the two molecular typing methods indicating a genetic diversity existed among the clinical S.typhimurium isolates in Guangdong province.Databank of S.typhimurium was constructed and could be used in laboratory surveillance programs.Under the characterization of analyzing similarity and evolution among S.typhimurium isolates,MLVA was suitable for cluster analysis on early detection of outbreaks caused by S.typhimurium.
