Survey on the Reservoirs of Yersinia Enterocolitica and Yersinia Enterocolitica‐like Bacteria in Scandinavia

Data pertaining to 330 Yersinia strains isolated from wild-living mammals, birds, fish, water, and soil in Scandinavia are summarized. The strains represent a broad spectrum of antigenic and biochemical variants interconnecting the species Y. enterocolitica and Y. pseudotuberculosis. A total of 136 strains were Y. enterocolitica sensu stricto; 55 strains produced acid rhamnose (Y. frederiksenii); 49 strains did not produce acid from sucrose (Y. kristensenii); 21 strains produced acid from rhamnose and melibiose (Y. intermedia); three strains were classified as Y. pseudotuberculosis. The remaining 66 strains could not be ascribed by any presently defined species. Seven strains were antigenically related to serogroup 3. Ecologically, Y. frederiksenii and Y. intermedia were more confined to aquatic ecosystems (fish and water) than Y. enterocolitica sensu stricto which was prevalent in both terrestrial and aquatic habitats. Y. kristensenii was ecologically comparable to Y. enterocolitica biotype 1, with their highest prevalence among terrestrial vertebrates. Y. frederiksenii and Y. intermedia seemed antigenically and biochemically more similar to Y. enterocolitica sensu stricto than Y. kristensenii.