[Phenotypic characterization and distribution of Yersinia in human and environmental samples]

The distribution of species and phenotypes of Yersinia isolated from environmental samples over an eight year period are compared to that of stool cultures obtained from patients of the same geographical location (Zaragoza, Spain). The number of samples and the percentage contamination were as follows: wastewater 362, 67.4%, freshwater 523, 13.4%, raw food 607, 24.5% and cooked food 1134, 7.9%. Yersinia enterocolitica was isolated significantly more frequently than other species in wastewater, while Yersinia intermedia was the most significant species found in freshwater. Significant differences between the percentage isolates of identified species in raw and cooked foods were not found. Fifteen different serogroups were identified from faeces, thirteen of which were also isolated from environmental samples. Three serogroups of Y. enterocolitica associated with human disease were isolated from the patients faeces as follows: O:3, 145 cases; O:8, 3 cases and O:5,27, 1 case. A low proportion were isolated from food: O:3, 3 strains; O:8, 2 strains and O:5,27, 5 strains. Only one isolate from serogroup O:3 was obtained from freshwater.