Tandem repeat analysis for surveillance of human Salmonella Typhimurium infections.
In Denmark, as part of the national laboratory-based surveillance system of human enteric infections, all Salmonella enterica serotype Typhimurium isolates are currently subtyped by using phage typing, antimicrobial resistance profiles, and pulsed-field gel electrophoresis (PFGE). We evaluated the value of real-time typing that uses multiple-locus variable-number tandem-repeats analysis (MLVA) of S. Typhimurium to detect possible outbreaks. Because only a few subtypes identified by PFGE and phage typing account for most infections, we included MLVA typing in the routine surveillance in a 2-year period beginning December 2003. The 1,019 typed isolates were separated into 148 PFGE types and 373 MLVA types. Several possible outbreaks were detected and confirmed. MLVA was particularly valuable for discriminating within the most common phage types. MLVA was superior to PFGE for both surveillance and outbreak investigations of S. Typhimurium.
Torpdahl
Mia
M
Department of Bacteriology, Mycology and Parasitology, Statens Serum Institut, Copenhagen, Denmark. mtd@ssi.dk
Sørensen
Gitte
G
Lindstedt
Bjørn-Arne
BA
Nielsen
Eva Møller
EM
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001434:Bacteriophage Typing; D003718:Denmark / Q000453:epidemiology; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D006801:Humans; D018598:Minisatellite Repeats; D017720:Molecular Epidemiology / Q000379:methods; D012480:Salmonella Infections / Q000453:epidemiology*; D012486:Salmonella typhimurium / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D018571:Sentinel Surveillance; D013045:Species Specificity; D020080:Tandem Repeat Sequences / Q000235:genetics*
D000900:Anti-Bacterial Agents