title: The evaluation and application of multilocus variable number tandem repeat analysis (MLVA) for the molecular epidemiological study of Salmonella enterica subsp. enterica serovar Enteritidis infection.
abstract: BACKGROUND
  Salmonella enterica subsp. enterica serovar Enteritidis (S. Enteritidis) is one of the most prevalent Salmonella serotypes that cause gastroenteritis worldwide and the most prevalent serotype causing Salmonella infections in China. A rapid molecular typing method with high throughput and good epidemiological discrimination is urgently needed for detecting the outbreaks and finding the source for effective control of S. Enteritidis infections.
  
  
  METHODS
  In this study, 194 strains which included 47 from six outbreaks that were well-characterized epidemiologically were analyzed with pulse field gel electrophoresis (PFGE) and multilocus variable number tandem repeat analysis (MLVA). Seven VNTR loci published by the US Center for Disease Control and Prevention (CDC) were used to evaluate and develop MLVA scheme for S. Enteritidis molecular subtyping by comparing with PFGE, and then MLVA was applied to the suspected outbreaks detection. All S. Enteritidis isolates were analyzed with MLVA to establish a MLVA database in Shenzhen, Guangdong province, China to facilitate the detection of S. Enteritidis infection clusters.
  
  
  RESULTS
  There were 33 MLVA types and 29 PFGE patterns among 147 sporadic isolates. These two measures had Simpson indices of 0.7701 and 0.8043, respectively, which did not differ significantly. Epidemiological concordance was evaluated by typing 47 isolates from six epidemiologically well-characterized outbreaks and it did not differ for PFGE and MLVA. We applied the well established MLVA method to detect two S. Enteritidis foodborne outbreaks and find their sources successfully in 2014. A MLVA database of 491 S. Enteritidis strains isolated from 2004 to 2014 was established for the surveillance of clusters in the future.
  
  
  CONCLUSIONS
  MLVA typing of S. Enteritidis would be an effective tool for early warning and epidemiological surveillance of S. Enteritidis infections.
authors.affiliation: Key Laboratory of Bio-resources and Eco-environment of the Ministry of Education, College of Life Sciences, Sichuan University, 29# Wangjiang Road, Chengdu, 610064, Sichuan, People's Republic of China. lewa92@163.com.
authors.forename: Yao
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Shenzhen Major Infectious Disease Control Key Laboratory, Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, Guangdong, People's Republic of China. 45317380@qq.com.
authors.forename: Xiaolu
authors.initials: X
authors.lastname: Shi
authors.affiliation: Shenzhen Major Infectious Disease Control Key Laboratory, Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, Guangdong, People's Republic of China. 30913142@qq.com.
authors.forename: Yinghui
authors.initials: Y
authors.lastname: Li
authors.affiliation: Shenzhen Major Infectious Disease Control Key Laboratory, Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, Guangdong, People's Republic of China. 815135471@qq.com.
authors.forename: Qiongcheng
authors.initials: Q
authors.lastname: Chen
authors.affiliation: Shenzhen Major Infectious Disease Control Key Laboratory, Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, Guangdong, People's Republic of China. 43798995@qq.com.
authors.forename: Min
authors.initials: M
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Bio-resources and Eco-environment of the Ministry of Education, College of Life Sciences, Sichuan University, 29# Wangjiang Road, Chengdu, 610064, Sichuan, People's Republic of China. 530787805@qq.com.
authors.forename: Wanli
authors.initials: W
authors.lastname: Li
authors.affiliation: Shenzhen Major Infectious Disease Control Key Laboratory, Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, Guangdong, People's Republic of China. 1186178352@qq.com.
authors.forename: Yaqun
authors.initials: Y
authors.lastname: Qiu
authors.affiliation: Shenzhen Major Infectious Disease Control Key Laboratory, Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, Guangdong, People's Republic of China. 920664498@qq.com.
authors.forename: Yiman
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Shenzhen Major Infectious Disease Control Key Laboratory, Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, Guangdong, People's Republic of China. 913197409@qq.com.
authors.forename: Yixiang
authors.initials: Y
authors.lastname: Jiang
authors.affiliation: Key Laboratory of Surveillance and Early-warning on Infectious Disease, Division of Infectious Disease, Chinese Center for Disease Control and Prevention, Beijing, People's Republic of China. kanbiao@icdc.cn.
authors.forename: Biao
authors.initials: B
authors.lastname: Kan
authors.affiliation: Key Laboratory of Bio-resources and Eco-environment of the Ministry of Education, College of Life Sciences, Sichuan University, 29# Wangjiang Road, Chengdu, 610064, Sichuan, People's Republic of China. qunsun@scu.edu.cn.
authors.forename: Qun
authors.initials: Q
authors.lastname: Sun
authors.affiliation: Shenzhen Major Infectious Disease Control Key Laboratory, Shenzhen Center for Disease Control and Prevention, Shenzhen, 518055, Guangdong, People's Republic of China. huqinghua03@163.com.|School of Life Sciences, Shenzhen University, Shenzhen, 518000, Guangdong, People's Republic of China. huqinghua03@163.com.
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Hu
mesh_terms: D015373:Bacterial Typing Techniques / Q000379:methods*; D002681:China / Q000453:epidemiology; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D016021:Epidemiologic Studies; D006801:Humans; D018598:Minisatellite Repeats; D058889:Molecular Typing / Q000379:methods*; D010802:Phylogeny; D012480:Salmonella Infections / Q000453:epidemiology / Q000382:microbiology*; D012477:Salmonella enteritidis / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*
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