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

Legislation introduced under European Commission Regulation (EC) n degrees 2073/2005 and later amendments (Reg. 1441/2007/EC, Reg. 365/2010/EC, Reg. 1089/2011/EC, Reg. 209/2013/EC) mandates that food business operators carry out microbiological analyses on meat carcass surfaces after slaughter procedures as part of hygiene monitoring of production. Besides setting forth general rules for sampling and sample preparation, Regulation EC 2073/2005 requires that operators comply with ISO 17604, which lists destructive and non-destructive sampling methods, selection of sampling sites, and rules for sample storage and transport. This study compares the effectiveness of destructive (excision) and non-destructive (sponge and wet-dry swabbing) methods for the recovery of total viable count (TVC) and Enterobacteriaceae on carcass surfaces. To do this, we pooled samples collected from carcasses of four animal species (cattle, n = 120; pigs, n = 130; horses, n = 84; and small ruminants [sheep and goats], n = 121). TVC and Enterobacteriaceae were enumerated and compared for each sampling method. Microbiological analyses were performed according to ISO 4833:2003 for TVC and ISO 21528:2004 for Enterobacteriaceae. The effectiveness of the sampling methods was analyzed by comparing the differences between the median of colony forming units per square centimeter (CFU/cm(2)) for TVC and Enterobacteriaceae recovered by each method. Non-parametric analysis of variance for repeated measures was applied for each species separately. Excision was the most effective method. The relationship between the CFU recovered by swabbing, by sponge, and by excision, for all species, was generally better than 1:5. This is in contrast with the Italian Ministry of Health Memorandum (23 December 2002), which states that non-destructive methods recover 20% of the destructive method. (C) 2014 Elsevier Ltd. All rights reserved.