title: Use of multiple-locus variable number tandem repeat analysis and phage typing for subtyping of Salmonella Enteritidis from sporadic human cases in the United States.
abstract: OBJECTIVE
  To investigate the genetic diversity among S. Enteritidis isolates from different geographic regions to evaluate the relationship between phage types (PTs) and variable number tandem repeat analysis (VNTR) loci.
  
  
  RESULTS
  We performed multiple-locus variable number tandem repeat analysis (MLVA) and phage typing on 245 S. Enteritidis isolates collected from sporadic human clinical cases in Michigan, Minnesota, New York, and Washington states between 2000 and 2007. Ninety-four MLVA types and 22 different PTs were identified. Specific PTs were associated with a predominant allele for certain VNTR loci. Cluster analysis using a minimum-spanning tree demonstrated two major clusters (I, II) and one minor cluster of isolates. PTs 8, 13a, 13 and 34 were significantly associated with MLVA cluster I. Phage types 1, 4, 6a, and 18 were significantly associated with MLVA cluster II.
  
  
  CONCLUSIONS
  We found significant association between MLVA-based clusters and PTs. Certain VNTR loci were associated with specific PTs and could serve as useful molecular markers for S. Enteritidis in epidemiological investigations.
  
  
  CONCLUSIONS
  MLVA genotyping in combination with phage typing can be used for effective characterization of S. Enteritidis isolates. It can also be useful for tracing possible sources during investigations of sporadic and outbreak cases of S. Enteritidis.
authors.affiliation:  National Food Safety and Toxicology Center, Michigan State University, East Lansing, MI, USA.
authors.forename: S
authors.initials: S
authors.lastname: Cho
authors.affiliation:  National Food Safety and Toxicology Center, Michigan State University, East Lansing, MI, USA.
authors.forename: T S
authors.initials: TS
authors.lastname: Whittam
authors.affiliation:  Minnesota Department of Health, St. Paul, MN, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Boxrud
authors.affiliation:  Minnesota Department of Health, St. Paul, MN, USA.
authors.forename: J M
authors.initials: JM
authors.lastname: Bartkus
authors.affiliation:  University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: S C
authors.initials: SC
authors.lastname: Rankin
authors.affiliation:  Michigan Department of Community Health, Lansing, MI, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Wilkins
authors.affiliation:  Michigan Department of Community Health, Lansing, MI, USA.
authors.forename: P
authors.initials: P
authors.lastname: Somsel
authors.affiliation:  Michigan Department of Community Health, Lansing, MI, USA.
authors.forename: F P
authors.initials: FP
authors.lastname: Downes
authors.affiliation:  New York State Department of Health, Albany, NY, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Musser
authors.affiliation:  New York State Department of Health, Albany, NY, USA.
authors.forename: T P
authors.initials: TP
authors.lastname: Root
authors.affiliation:  Cornell University, Ithaca, NY, USA.
authors.forename: L D
authors.initials: LD
authors.lastname: Warnick
authors.affiliation:  Cornell University, Ithaca, NY, USA.
authors.forename: M
authors.initials: M
authors.lastname: Wiedmann
authors.affiliation:  National Food Safety and Toxicology Center, Michigan State University, East Lansing, MI, USA.
authors.forename: A M
authors.initials: AM
authors.lastname: Saeed
mesh_terms: D000293:Adolescent; D000328:Adult; D000483:Alleles; D001434:Bacteriophage Typing / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D016000:Cluster Analysis; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D005843:Geography; D006801:Humans; D008297:Male; D008875:Middle Aged; D018598:Minisatellite Repeats; D058885:Multilocus Sequence Typing / Q000379:methods*; D012477:Salmonella enteritidis / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D014481:United States; D055815:Young Adult