Yersinia enterocolitica in borwn trout (Salmo trutta L.) from Norway

In this pilot study, 20 brown trout (Salmo trutta L.) from one area in Western Norway were investigated for the presence of Yersinia enterocolitica (Y.e.). Three strains were isolated from three of these trout. All strains were classified as Y.e. on the basis of biochemical properties. One of the strains showed antigenic relationship to Y.e O-serotype 17. A second strain was antigenically related both to Y.e. and Y. pseudotuberculosis: Agglutination against Y.e. O-antisera 4-33, 18, and 21, was obtained and against Y. pseudotuberculosis O-antiserum II B. The third culture was not agglutinated by our sera. The biochemical properties of the strains are presented. The capability of fish to spread Y.e. is discussed.