title: The effect of blast chilling on occurrence of human pathogenic Yersinia enterocolitica compared to Campylobacter spp. and numbers of hygienic indicators on pig carcasses.
abstract: In this study, the occurrence of Yersinia enterocolitica on pig carcasses was compared to the occurrence of Campylobacter spp., and to the numbers of aerobic micro-organisms, coliform bacteria, thermotolerant coliform bacteria, and Escherichia coli before and after blast chilling. Y. enterocolitica O:3/biovar 4 was isolated from five (8.3%) of 60 carcasses before blast chilling, and also from five of them 1 h after blast chilling. Therefore this procedure does not seem to have a significant effect on the occurrence of pathogenic Y. enterocolitica on pig carcasses. Y. enterocolitica O:9/biovar 2 was isolated from a pig source in Norway for the first time when this sero/biovariant was isolated from one of the carcasses before blast chilling. Campylobacter spp. was isolated from 34 (56.7%) of 60 carcass samples before blast chilling. After blast chilling Campylobacter spp. was isolated from only one (1.7%) of the 60 carcasses. There was a significant decrease of the numbers of coliform bacteria, thermotolerant coliform bacteria and E. coli after blast chilling. The number of aerobic micro-organisms did not decrease after this step. In contrast to the drastic decrease in the occurrence of campylobacter-positive carcasses and the significant decrease of the numbers of coliform bacteria, thermotolerant coliform bacteria and E. coli, blast chilling does not seem to have a significant effect on the occurrence of human pathogenic Y. enterocolitica on pig carcasses.
authors.affiliation: Norwegian School of Veterinary Science, Department of Food Safety and Infection Biology, P. O. Box 8146 Dep., N-0033 Oslo, Norway. truls.nesbakken@veths.no
authors.forename: Truls
authors.initials: T
authors.lastname: Nesbakken
authors.forename: Karl
authors.initials: K
authors.lastname: Eckner
authors.forename: Ole-Johan
authors.initials: OJ
authors.lastname: Røtterud
mesh_terms: D000003:Abattoirs; D000818:Animals; D002167:Campylobacter / Q000254:growth & development / Q000302:isolation & purification*; D003080:Cold Temperature; D015169:Colony Count, Microbial; D003257:Consumer Product Safety; D005506:Food Contamination / Q000032:analysis*; D005511:Food Handling / Q000379:methods*; D005516:Food Microbiology; D006801:Humans; D006920:Hygiene; D013552:Swine / Q000382:microbiology*; D015008:Yersinia enterocolitica / Q000254:growth & development / Q000302:isolation & purification*