Experimental Comparison of Excision and Swabbing Microbiological Sampling Methods for Carcasses
Bovine sides, ovine carcasses, and porcine carcasses were individually inoculated by dipping in various suspensions of a marker organism (Escherichia coli K-12 or Pseudomonas fluorescens), alone or in combination with two meat-derived bacterial strains, and were sampled
by two standard methods: cotton wet-dry swabbing and excision. The samples were examined for bacterial counts on plate count agar (PCA plate counts) and on violet red brilliant green agar (VRBGA plate counts) by standard International Organization for Standardization methods. Average bacterial
recoveries by swabbing, expressed as a percentage of the appropriate recoveries achieved by excision, varied widely (2 to 100%). Several factors that potentially contributed to relatively low and highly variable bacterial recoveries obtained by swabbing were investigated in separate experiments.
Neither the difference in size of the swabbed area (10, 50, or 100 cm2 on beef carcasses) nor the difference in time of swabbing (20 or 60 min after inoculation of pig carcasses) had a significant effect on the swabbing recoveries of the marker organism used. In an experiment with
swabs preinoculated with the marker organism and then used for carcass swabbing, on average, 12% of total bacterial load was transferred inversely (i.e., from the swab to the carcass during the standard swabbing procedure). In another experiment, on average, 14% of total bacterial load was
not released from the swab into the diluent during standard swab homogenization. Use of custom-made swabs with abrasive butts, around which metal pieces of pan scourers were wound, markedly increased PCA plate count recoveries from noninoculated lamb carcasses at commercial abattoirs compared
with cotton swabs. In spite of the observed inferiority of the cotton wet-dry swabbing method compared with the excision method for bacterial recovery, the former is clearly preferred by the meat industry because it does not damage the carcass. Therefore, further large-scale evaluation of
the two carcass sampling methods has been undertaken under commercial conditions and reported separately.
Document Type: Research Article
Department of Clinical Veterinary Science, Division of Farm Animal Science, University of Bristol, Langford, Bristol BS40 5DU, UK
Microbiology Department, Direct Laboratories Ltd., Wergs Road, Wolverhampton, West Midlands WV6 8QT, UK
Department of Farm Animal and Equine Medicine and Surgery, University of London RVC, Hawkshead Lane, North Mymms, Hertfordshire AL9 7TA, UK
Publication date: October 1, 2005
More about this publication?
IAFP members must first sign in on the right to access full text articles of JFP
First published in 1937, the Journal of Food Protection®
, is a refereed monthly publication. Each issue contains scientific research and authoritative review articles reporting on a variety of topics in food science pertaining to food safety and quality. The Journal
is internationally recognized as the leading publication in the field of food microbiology with a readership exceeding 11,000 scientists from 70 countries. The Journal of Food Protection®
is indexed in Index Medicus, Current Contents, BIOSIS, PubMed, Medline, and many others.
Print and online subscriptions are available to Members and Institutional subscribers. Online visitors who are not IAFP Members or journal subscribers will be charged on a pay-per-view basis. Information can be obtained by calling +1 800.369.6337; +1 515.276.3344; fax: +1 515.276.8655, E-mail: firstname.lastname@example.org
or Web site: www.foodprotection.org
- Information for Authors
- Submit a Paper
- Subscribe to this Title
- Membership Information
- Information for Advertisers
- ingentaconnect is not responsible for the content or availability of external websites