title: Development and comparison of a generic multiple-locus variable-number tandem repeat analysis with pulsed-field gel electrophoresis for typing of Salmonella enterica subsp. enterica.
abstract: OBJECTIVE
  Salmonella enterica subsp. enterica causes salmonellosis in humans and animals. Serovar-specific multiple-locus variable-number tandem repeat analysis (MLVA) is widely used for Salmonella surveillance; however, isolates have to be serotyped prior to MLVA typing and only the most common serovars can be typed. We developed a MLVA scheme for high-discriminatory typing of Salmonella.
  
  
  RESULTS
  Sixty-six unique VNTRs were investigated and the polymorphisms of seven promising VNTRs were evaluated with a panel 163 diverse isolates of 14 serotypes of significance for human health. Five VNTRs were selected for MLVA analysis. The discriminatory power was evaluated within serovars by 163 isolates and MLVA yielded 79 genotypes (DI of 0·9790) and pulsed-field gel electrophoresis (PFGE) revealed 87 genotypes (DI of 0·9989). MLVA divided each serotype into 2-8 different profiles and identified six pairs of outbreak-related strains.
  
  
  CONCLUSIONS
  The technique showed a high-discriminatory power within most serotypes comparable with or better than that of PFGE.
  
  
  CONCLUSIONS
  This MLVA assay makes it possible to use a single typing method for Salmonella surveillance and outbreak investigations. This allows inexpensive and fast surveillance for laboratories without resources for both serotyping and molecular typing, e.g. PFGE or sequence-based methods, and thereby improve the effectiveness of epidemiological investigations of Salmonella infections globally.
authors.affiliation: The Unit for Foodborne Infections, Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark.|National Food Institute, Technical University of Denmark, Søborg, Denmark.
authors.forename: M K
authors.initials: MK
authors.lastname: Kjeldsen
authors.affiliation: The Unit for Foodborne Infections, Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark.
authors.forename: M
authors.initials: M
authors.lastname: Torpdahl
authors.affiliation: National Veterinary Institute, Technical University of Denmark, Frederiksberg, Denmark.
authors.forename: K
authors.initials: K
authors.lastname: Pedersen
authors.affiliation: The Unit for Foodborne Infections, Department of Microbiology and Infection Control, Statens Serum Institut, Copenhagen, Denmark.
authors.forename: E M
authors.initials: EM
authors.lastname: Nielsen
mesh_terms: D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods*; D006801:Humans; D018598:Minisatellite Repeats / Q000235:genetics*; D058889:Molecular Typing / Q000379:methods*; D012480:Salmonella Infections / Q000382:microbiology; D019779:Salmonella enterica / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial
keywords: Salmonella; epidemiology; genotyping; multiple-locus variable-number tandem repeat analysis; surveillance