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

The origins of human contamination withYersinia 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 ofYersinia. Four hundred fifty-nine strains ofYersinia were isolated. We report the first isolations of typicalY. enterocolitica belonging to classical or new biotypes and ofY. enterocolitica-like organisms (sucrose negative; rhamnose positive; melibiose and rhamnose positive) from soil samples, earthworms, crops, and birds. Sucrose-negativeY. 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 ofY. enterocolitica infections is discussed.