title: virF-positive Yersinia pseudotuberculosis and Yersinia enterocolitica found in migratory birds in Sweden.
abstract: During spring and autumn migrations, 468 fecal samples from 57 different species of migratory birds were collected in Sweden. In total, Yersinia spp. were isolated from 12.8% of collected samples. The most commonly found species was Yersinia enterocolitica, which was isolated from 5.6% of all collected samples, followed by Y. intermedia (3.8%), Y. frederiksenii (3.0%), Y. kristensenii (0.9%), Y. pseudotuberculosis (0.6%), and Y. rohdei (0.4%). The pathogenic, virF-positive Y. pseudotuberculosis strains were recovered from three thrushes. These strains belonged to the same bioserotype, 1/O:2, but had two different profiles as determined by pulsed-field gel electrophoresis with NotI and SpeI enzymes. In addition, 10 Y. enterocolitica strains, all from barnacle geese, belonged to bioserotype 3/O:3, which is associated with human disease. Two of the strains were pathogenic, carrying the virF gene on their plasmids. All pathogenic Y. pseudotuberculosis and Y. enterocolitica strains were recovered during the spring, and as the birds were caught during active migration they likely became infected at an earlier stage of the migration, thus potentially transporting these bacterial pathogens over long geographical distances.
authors.affiliation: Department of Food and Environmental Hygiene, Faculty of Veterinary Medicine, FIN-00014 University of Helsinki, Finland. taina.niskanen@helsinki.fi
authors.forename: Taina
authors.initials: T
authors.lastname: Niskanen
authors.forename: Jonas
authors.initials: J
authors.lastname: Waldenström
authors.forename: Maria
authors.initials: M
authors.lastname: Fredriksson-Ahomaa
authors.forename: Björn
authors.initials: B
authors.lastname: Olsen
authors.forename: Hannu
authors.initials: H
authors.lastname: Korkeala
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis*; D001717:Birds / Q000382:microbiology*; D004641:Emigration and Immigration; D013548:Sweden; D037521:Virulence Factors; D015008:Yersinia enterocolitica / Q000302:isolation & purification* / Q000472:pathogenicity; D015011:Yersinia pseudotuberculosis / Q000302:isolation & purification* / Q000472:pathogenicity
chemical_list: D001426:Bacterial Proteins; D037521:Virulence Factors