Incidence of coagulase positive Staphylococcus on beef carcasses in three Australian abattoirs

The contamination of beef carcasses with coagulase-positive staphylococci ( CPS) was studied at three beef abattoirs (A, B and C). The incidence and th e number of CPS were determined on cattle hides immediately after slaughter and on three carcass sites (brisket, flank and round) at different points during processing along the slaughter line. The incidence of CPS on cattle hides ranged from 20 to 68.6%. At abattoir A, 6.5% of the carcasses sampled before evisceration were contaminated with CPS, compared to 40% of the car casses after evisceration. The incidence on carcasses changed little during further processing; however, after chilling for 72 h, the incidence increa sed to 83%. After evisceration, the brisket and flank areas were more often contaminated than the round. A similar pattern of contamination was observ ed at abattoir B. At abattoir C, 26.7% of the samples collected before evis ceration were contaminated and this fell to 16.7% after evisceration. After chilling for 72 h, the incidence of carcass contamination with CPS increas ed to 46.7%. The average number of CPS on contaminated carcasses prior to a nd after overnight chilling was less than 50 colony-forming units (cfu)/cm( 2) and, after weekend chilling, increased to 64 and 112 cfu/cm(2) in abatto irs A and B, respectively. Of the isolates tested, 71.4% produced staphyloc occal enterotoxin and 21% could not be classified phenotypically. The hands of workers and environmental sites associated with the evisceration proces s were examined for CPS at abattoir A. Hands were heavily contaminated and were the likely source of CPS contamination at this abattoir. (C) 1999 Else vier Science B.V. All rights reserved.