Biochemical, serological, and phage typing characteristics of 459 Yersinia strains isolated from a terrestrial ecosystem

The origins of human contamination with Yersinia enterocolitica are still unknown. We have investigated the major components of a terrestrial ecosystem (soil, earthworms, field voles, shrews, crops, hares, rabbits, and birds) for the presence of Yersinia. Four hundred fifty-nine strains of Yersinia were isolated. We report the first isolations of typical Y. enterocolitica belonging to classical or new biotypes and of Y. enterocolitica-like organisms (sucrose negative; rhamnose positive; melibiose and rhamnose positive) from soil samples, earthworms, crops, and birds. Sucrose-negative Y. enterocolitica strains and biotypes 1, 2, and 3, usually associated with human nonmesenteric syndromes, are predominant in soil, which can be considered as a reservoir for these biotypes. Y. enterocolitica serogroups O:3 and O:9, strains of which are responsible in Europe for human mesenteric syndromes, were not found in this study. The epidemiology of Y. enterocolitica infections is discussed.