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Effects of chilling on sampling of bacteria attached to swine carcasses
Author(s) -
Yu S.L.,
Cooke P.H.,
Tu S.I.
Publication year - 2001
Publication title -
letters in applied microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.698
H-Index - 110
eISSN - 1472-765X
pISSN - 0266-8254
DOI - 10.1046/j.1472-765x.2001.00886.x
Subject(s) - bacteria , biology , sampling (signal processing) , microbiology and biotechnology , veterinary medicine , medicine , genetics , filter (signal processing) , computer science , computer vision
S.‐L. YU, P.H. COOKE AND S.‐I. TU. 2001. Two microbiological sampling techniques, excision and sponge swabbing, were compared by determining counts of aerobic bacteria, coliforms and injured coliforms from 20 de‐haired swine carcasses before and after chilling. Excised jowl skin produced significantly greater counts of the three types of bacteria than sponge swabs. Aerobic bacteria, coliforms and injured coliforms recovered by sponge swabbing carcasses before chilling were 11·6%, 0·9% and 11·0% of excised samples, respectively; the corresponding percentages recovered after chilling were 23·9%, 11·1% and 5·0%. Numbers of all bacteria present on the post‐chill carcasses were substantially lower than on the pre‐chill carcasses. Excision usually produced more countable plates for coliforms and injured coliforms on chilled carcasses than sponge swabbing and therefore, is more suitable in estimating low numbers of faecal bacteria on chilled carcasses. To explore the possible structural bases for these findings, skin samples were inoculated with 10 2 –10 7 cfu cm –2 faecal bacteria and examined by scanning electron microscopy. Chilled samples showed bacteria and biofilm embedded in superficial crevices, which underlies a possible reason for the lower recovery of bacterial cells by the sponge swabbing. The study indicates that the differences between sampling techniques may be a result of the chilling process of swine carcasses.