Genotyping of outbreak-associated and sporadic Yersinia pseudotuberculosis strains by novel multilocus variable-number tandem repeat analysis (MLVA).
Yersinia pseudotuberculosis human infections caused by serotype O:1 and O:3 isolates have been common in Finland and have also caused outbreaks. Epidemiological studies on the outbreaks have been limited by the lack of accurate typing methods. During the recent years, multilocus variable-number tandem repeat analysis (MLVA) has been successfully applied for molecular typing of several bacterial pathogens. We designed an MLVA scheme based on seven loci for Y. pseudotuberculosis. The method was able to discriminate clinical isolates of serotypes O:1 and O:3 into several MLVA types. The MLVA profiles were based on the number of 6 to 9 bp long tandem repeats in each locus. The number of repeats varied from 1 to 23 depending on the locus. The loci were all located in the bacterial chromosome for stability of the markers. The MLVA method developed was serotype-specific and will be a new additional tool for the epidemiological investigations of isolates associated with disease outbreaks and for comparison of sporadic isolates.
Bacteriology Unit, Department of Infectious Disease Surveillance and Control, National Institute for Health and Welfare (THL), P.O. Box 30, FI-00271 Helsinki, Finland. Electronic address: jani.halkilahti@thl.fi.
Jani
J
Halkilahti
Kaisa
K
Haukka
Anja
A
Siitonen
D015373:Bacterial Typing Techniques / Q000379:methods; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D060005:Genotyping Techniques / Q000379:methods*; D006801:Humans; D018598:Minisatellite Repeats; D058885:Multilocus Sequence Typing / Q000379:methods*; D015011:Yersinia pseudotuberculosis / Q000145:classification / Q000302:isolation & purification*; D015012:Yersinia pseudotuberculosis Infections / Q000453:epidemiology* / Q000382:microbiology
D004269:DNA, Bacterial
Genotyping; MLVA; VNTR; Yersinia pseudotuberculosis