Abstract
50 drinking-water specimens, selected at random, were examined for Yersinia enterocolitica in February 1970 and April 1971. 11 cultures were isolated from 10 of these specimens which on a serological and/or biochemical basis could be classified as Y. enterocolitica. Two of these cultures were antigenically identical with previously described serotypes (serotypes 7 and 13), 7 showed antigenic relationship to serotypes previously described although they were not identical (serotypes 2, 4, 6 and 16), whilst the 2 remaining cultures represented new serotypes. The serotypes which are most frequently found in human Y. enterocolitica infections were not shown in these specimens selected at random, but it is presumed that these serotypes can also be conveyed through drinking-water.