Purpose: The purpose of this project was to determine 1) the prevalence of non-O157 STEC on beef hides and carcasses in U.S. export abattoirs in Costa Rica and 2) if current practices and interventions controlled final carcass contamination.
Methods: Three abattoirs (A, B, C) were visited during November of 2012. Carcasses were followed and the foreshank swabbed at three stages: hides, prior to evisceration, and after application of the antimicrobial intervention (carcass spray with a 200-ppm peroxyacetic acid solution). Thirty swabs were collected at each point in all plants. An FSIS-approved real-time PCR protocol was used to assess the presence of non-O157 STEC serogroups O26, O45, O103, O111, O121, and O145 using the DuPont Qualicon BAX® System.
Results: Non-O157 STEC prevalence in Plant A was 86.7% (hides; n = 26/30), 6.75 (pre-evisceration; n = 2/30) and 0% (post-intervention; n = 0/30); Plant B prevalence was 96.7% (hides; n = 29/30), 33.3% (pre-evisceration; n = 10/30) and 6.7% (post-intervention; n = 2/30); prevalence in Plant C was 96.7% (hides; n = 29/30), 3.3% (pre-evisceration; n = 1/30) and 0% (post-intervention; n = 0/30). Serogroups O103 and O45 were the most prevalent in Plant A with corresponding frequencies of 17/35 (48.6%) and 15/35 (42.9%). In Plant B, O121 and O103 were predominant with 37/129 (28.7%) and 35/129 (27.1%), respectively, whereas in Plant C, O145 and O26 predominated with 27/109 (24.8%) and 23/109 (21.1%), respectively.
Significance: These results highlight the significance of hides as a major source of STEC on carcasses. Additionally, proper dressing procedures along with effective antimicrobial interventions reduce contamination with STEC on final carcasses. All of the visited abattoirs exporting to the US are controlling contamination and should continue with current interventions and on-going testing for verification.