Browsing by Author "Eklund, Kirsi-Maria"

Yersinia enterocolitica is an important zoonotic food-borne pathogen which in Finland is reported to be the cause of hundreds of gastroenteritis cases a year. The species is very heterogenic and comprises of both highly virulent and harmless apathogenic strains. The sources of Y. enterocolitica infection and the reservoirs of pathogenic strains are not yet well-known. In this work, 91 Y. enterocolitica isolates from 39 domestic sheep were characterized using different phenotypic and genotypic methods. Three different biotypes were identified: usually harmless environmental biotype 1A, a common enteropathogenic biotype 2 and a rare pathogenic biotype 5. All biotype 2 and 5 strains carried chromosomal ail, inv, myfA and ystA genes, and plasmid borne virulence genes yadA and virF. Biotype 1A isolates carried several chromosomal virulence genes, Notably also the ail which has a strong correlation with Y. enterocolitica pathogenicity. In pathogenic biotypes, only natural resistance to antimicrobials was detected. In PFGE-analysis, biotype 1A had several genotypes, whereas strains belonging to biotypes 2 or 5 showed only a limited amount of variation. ail and gyrB genes were partially sequenced from a selection of strains, both of which revealed variation between different biotypes. This study indicates that sheep are a reservoir for pathogenic Y. enterocolitica in Finland. Without further analysis the link between sheep and human illness cannot yet be established.