ABSTRACT
Data on the first human infections with Y. enterocolitica in Canada were published by Lafleur et al. in Quebec, between 1966 and 1972. Practically all Y. enterocolitica strains isolated from acute gastroenteritis, septicemia, or deep-seated infections were biochemically typical and belonged to one of the previously mentioned predominant O serotypes. There are many schemes available for biochemical characterization and biotyping of Y. enterocolitica cultures and undoubtedly, each scheme has its merits. Serotyping of Y. enterocolitica cultures in conjunction with complete biochemical identification proved to be a very valuable method for differentiation of clinical pathogenic strains of environmental strains and for epidemiological purposes. Phage typing of indole-negative strains of Y. enterocolitica, serotype O:3, was a valuable procedure for typing "Continental" distribution. Nonhuman strains of Y. enterocolitica may be conveniently divided into environmental and animal strains. Most environmental strains were indole-positive, biochemically and serologically atypical, and significantly different from the strains isolated from human infections.
