@article{mbs:/content/journal/ijsem/10.1099/00207713-31-4-401, author = "Kapperud, Georg. and Bergan, Tom. and Lassen, Jørgen.", title = "Numerical Taxonomy of Yersinia enterocolitica and Yersinia enterocolitica-Like Bacteria", journal= "International Journal of Systematic and Evolutionary Microbiology", year = "1981", volume = "31", number = "4", pages = "401-419", doi = "https://doi.org/10.1099/00207713-31-4-401", url = "https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/00207713-31-4-401", publisher = "Microbiology Society", issn = "1466-5034", type = "Journal Article", abstract = "We studied the taxonomic interrelationships of 332 Yersinia strains by using a numerical analysis that was based on 46 cultural and biochemical characters and involved both a hierarchical clustering procedure and a principal components analysis. Yersinia pseudotuberculosis and Yersinia kristensenii were recognized as relatively distinct phenotypic clusters. Y. kristensenii was further distinguishable from the remaining taxa by antigenic and enterotoxigenic parameters. These results supported the suggestion that Y. kristensenii deserves species status. On the other hand, Yersinia enterocolitica sensu stricto, Yersinia frederiksenii, and Yersinia intermedia constituted a phenotypic continuum. Each of these three taxa prevailed in different parts of a heterogeneous cluster of strains that were connected by intermediate phenotypes. This pattern of overlapping phenotypes was supported further by antigenic properties, habitat preferences, and pathogenic characteristics. Thus, we failed to find a basis for separating Y. enterocolitica sensu stricto, Y. frederiksenii, and Y. intermedia on phenetic, ecological, or pathogenic grounds. We suggest that the taxonomic relationships among these nomenspecies may require further evaluation. Two phenetic clusters contained strains not ascribable to any presently defined species. One of these clusters consisted mainly of rhamnose-positive, sucose-negative strains and the other contained strains negative for sucrose or ornithine decarboxylase or both.", }