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The incidence of Yersinia enterocolitica and Yersinia enterocolitica ‐like organisms in raw and pasteurized milk in Northern Ireland
Author(s) -
Walker S. J.,
Gilmour A.
Publication year - 1986
Publication title -
journal of applied bacteriology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.889
H-Index - 156
eISSN - 1365-2672
pISSN - 0021-8847
DOI - 10.1111/j.1365-2672.1986.tb04266.x
Subject(s) - yersinia enterocolitica , raw milk , pasteurization , biology , microbiology and biotechnology , food science , bacteria , yersinia , genetics
Yersinia enterocolitica and Y. enterocolitica ‐like bacteria were frequently isolated from samples of both raw bulked milk (34/150) and farm bottled (raw) milk (5/20). These bacteria were also found to contaminate creamery pasteurized milk (6/100 samples) and farm pasteurized milk (4/50 samples). Although Y. enterocolitica was the most commonly isolated species, Y. intermedia and Y. frederiksenii were also frequently obtained (52, 31 and 15% of isolates, respectively). Also, one atypical strain was identified as Y. aldovae . The Y. enterocolitica strains were largely biotype 1 (20/27) including five strains which could ferment lactose. One third of the Y. enterocolitica strains were not typable, but of those which were, the serotypes were 0:34 (18.5%), 0:5,27 (18.5%), 0:6,30 (15%), 0:4 (11%) and 0:7 (4%). Pre‐enrichment in trypticase‐soy broth (TSB) (at 22°C for 24 h) followed by selective enrichment in bile‐oxalate‐sorbose broth (at 22°C for 6 d) allowed the recovery of 92.3% of all isolates, as compared with 15.4% using cold enrichment in TSB at 4°C for 21 d.