Development of Multiple-Locus Variable-Number Tandem-Repeat Analysis for Yersinia enterocolitica subsp. palearctica and Its Application to Bioserogroup 4/O3 Subtyping

Abstract

Yersinia enterocolitica bioserogroup 4/O3 is the predominant causative agent of yersiniosis in Europe and North America. Multiple-locus variable-number tandem-repeat analysis (MLVA) was developed to improve the resolution power of classical genotyping methods. MLVA based on six loci was able to distinguish 76 genotypes among 91 Y. enterocolitica isolates of worldwide origin and 41 genotypes among 51 nonepidemiologically linked bioserogroup 4/O3 isolates, proving that it has a high resolution power. However, only a slight correlation of the MLVA genotypes and the geographic distribution of the isolates was observed. Although MLVA was also capable of distinguishing strains of Y. enterocolitica subsp. palearctica O9 and O5,27, there was only a minor correlation between the MLVA genotypes and serogroups. MLVA may be a helpful tool for epidemiological investigations of Y. enterocolitica subsp. palearctica outbreaks.

Multiple-Locus Variable-Number Tandem-Repeat Analysis in Genotyping Yersinia enterocolitica Strains from Human and Porcine Origins

“…The minimal length of a V2A fragment has been reported to be 263 bp (20). However, the sequencing results of our study showed that these 232-to 262-bp fragments contained two to seven VNTR units.…”

“…The method showed a high discriminatory capacity, since 312 different MLVA types were found among 379 Y. enterocolitica strains. MLVA found 45 genotypes among 62 Y. enterocolitica 4/O:3 strains in a previous study (20) and 77 types among 88 Y. enterocolitica strains in another study (7). When strains with the same epidemiological sources were excluded, we detected 262 MLVA types among 278 strains, whereas 21 Y. enterocolitica strains with no epidemiological link were previously discriminated into 20 genotypes using MLVA (20).…”

“…Compared with the amplicon lengths and corresponding tandem-repeat numbers reported in previous studies (7,20), V2A primers produced PCR products that were unexpectedly short, as their lengths were only 232 to 262 bp. The minimal length of a V2A fragment has been reported to be 263 bp (20).…”

“…MLVA found 45 genotypes among 62 Y. enterocolitica 4/O:3 strains in a previous study (20) and 77 types among 88 Y. enterocolitica strains in another study (7). When strains with the same epidemiological sources were excluded, we detected 262 MLVA types among 278 strains, whereas 21 Y. enterocolitica strains with no epidemiological link were previously discriminated into 20 genotypes using MLVA (20). Interestingly, with randomly chosen clinical strains isolated from human fecal samples in Finland, we observed similar MLVA types over a period of several years.…”

“…Different genotypes are distinguished by the number of repeats in each locus (18). The application developed for Y. enterocolitica 4/O:3 uses six VNTR loci, i.e., V2A, V4, V5, V6, V7, and V9 (20). MLVA also has proved successful with Y. enterocolitica serotype O:9 (7,8,21,22).…”