Development and comparison of a generic multiple-locus variable-number tandem repeat analysis with PFGE for typing of Salmonella entericasubsp. enterica

Marianne Kirstine Kjeldsen, Mia Torpdahl, Karl Pedersen, Eva Møller Nielsen

Research output: Contribution to journalJournal articleResearchpeer-review


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.
Methods and 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 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.
The technique showed a high discriminatory power within most serotypes comparable with or better than that of PFGE.
Significance and impact of the Study
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.
Original languageEnglish
JournalJournal of Applied Microbiology
Issue number6
Pages (from-to)1707-1717
Publication statusPublished - 2015

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