Contribution to the definition and the taxonomy of Yersinia enterocolitica.

The phenotypic study of 6,000 strains of Y. enterocolitica and Y. enterocolitica-like organisms by the biochemical reaction of the identification of Enterobacteriaceae on one hand and of 100 strains representing different chemiotypes by an auxanogram technique shows a large homogeneity of these strains which are apparated from the other Yersinia within Enterobacteriaceae. Six chemiotypes are described. The strains fermenting thamnose, similar to chemiotype I, can be subdivided in two groups according to the acidification of melibiose. The future and the denomination of these strains are discussed. The biochemical characteristics difining Y. enterocolitica and six chemiotypes are defined.