The source of Yersinia spp. in pasteurized milk: an investigation at a dairy.

摘要: Pasteurized bottled milk supplied by a single dairy was frequently found to be contaminated with Yersinia spp. Investigations were carried out at the in an effort pinpoint source of these organisms. Viable counts obtained from bottle rinses indicated that washing often unsatisfactory, and on one occasion Y. frederiksenii isolated pooled rinse water six bottles. Samples taken arrival various stages following pasteurization. Heat resistance tests strains yersinia pasteurized they would not survive pasteurization process. However two sample immediately after but before bottling. The thermograph time/temperature conditions applied during adequate. presence this stage therefore suggests undetectable levels raw being allowed contaminate milk. absence cartoned samples produced same day as environmental contamination filler valve also may have occurred times. Results investigation indicate increased vigilance is required ensure proper operation pasteurizers washers.