Microbiological Sampling of Carcasses by Excision or Swabbing with Three Types of Sponge or Gauze

Abstract

Fifty-five bovine, 50 equine, 60 ovine, and 50 porcine carcasses were sampled in a slaughterhouse in eastern Spain. Two samples were taken from each carcass, one using the excision method and the other using the swabbing method. Four different materials were used for swabbing: cellulose, polyurethane, or viscose sponges, and medical gauze. Samples were collected at the end of the process by four different people before the carcasses were taken to the cooler. The samples were examined for total viable bacteria counts (TVCs) and Enterobacteriaceae counts (ECs). The mean TVC for all species sampled by excision was 4.50 log CFU/cm(2), which was significantly higher than the 3.53 log CFU/cm(2) obtained by swabbing. The TVCs obtained using gauze and the cellulose and polyurethane sponges were significantly higher (P < 0.05) than the corresponding TVCs obtained using viscose sponges. Animal species, the person who collected the samples, and microbiological load also had a significant effect on TVC. ECs were obtained from 82.8% of excision samples, from larger percentages of samples obtained using cellulose or polyurethane sponges or gauze swabs, but from smaller percentages of samples obtained using viscose sponges. The Enterobacteriaceae load significantly influenced the EC. In contrast, animal species and the person who collected the samples had no significant effect. The cellulose sponge, polyurethane sponge, and gauze gave high mean log counts of aerobic bacteria and Enterobacteriaceae, which makes these swab types suitable for use in slaughterhouses for the purpose of assessing production process hygiene.

Comparison of three sampling methods for the quantification of methicillin-resistant Staphylococcus aureus on the surface of pig carcases

“…This is in line with other studies carried out on pig carcases (Ghafir & Daube, 2008;Lindblad, 2007;Martinez, Celda, Anastasio, Garcia, & Lopez-Mendoza, 2010;Pepperell et al, 2005).…”

Microbiological recovery from bovine, swine, equine, and ovine carcasses: Comparison of excision, sponge and swab sampling methods

“…Bacterial recovery from carcass surfaces depends on the sampling method used (Dorsa et al, 1996;Fliss et al, 1991;Gill et al, 2001;Martinez et al, 2010). It has also been reported that excision can recover the largest number of bacteria from a given area of carcass surface (Sharpe et al, 1996).…”

Preliminary evaluation of good sampling locations on a pig carcass for livestock-associated MRSA isolation

“…Samples were taken after rapid cooling of the carcasses. S. aureus is able to bind strongly to corneocytes, which could imply that sponge swabbing might not be sufficient to collect all MRSA present and a more destructive method, such as cutting of slices is needed as was reported for Salmonella or E. coli (Ghafir and Daube, 2008;Martinez et al, 2010). Another possibility could be the reduced viability of MRSA after cooling of the carcasses, even though S. aureus is able to persist colder temperatures (Onyango et al, 2012).…”