Presence of Clostridium difficile on pig carcasses during the slaughter process

Abstract

Clostridium difficile can be isolated from the intestines of healthy pigs (10%) at slaughter age. Contamination of meat during the slaughter process has been described for many intestinal bacteria, i.e. Salmonella. Since C. difficile spores could survive the recommended cooking temperatures for meat and infect the consumer, C. difficile contaminated meat could be a potential public health risk. The aim of this study was to determine to which level contamination of the carcasses occurs and whether the presence of C. difficile on carcasses of pigs changes during the slaughter process. Rectal samples, cork bore samples and swab samples were taken from carcasses at the beginning and the end of the slaughter process. To determine whether the prevalence of C. difficile on carcasses correlates with its presence in meat, pork trimmings were also collected. The samples were cultured with both quantitative and qualitative culture methods. C. difficile was not isolated from any of the carcasses or the pork trimmings with the quantitative culture method. Even with qualitative culture methods cork bore samples of a carcass from a pig that intestinally carried C. difficile were negative. With the qualitative culture method C. difficile was isolated from 28 (18%) carcasses that were sampled with electrostatic cloths directly after stunning, but from none of the 163 carcasses that were sampled after chilling. C. difficile was cultured from two of the eight pork trimmings. The results of this study indicate that carcasses can be contaminated at the beginning of the slaughter process with C. difficile, although with very low numbers of spores, since the bacterium was only recovered from samples when qualitative culture methods were used. The procedures along the slaughterline are sufficient to remove C. difficile from the carcasses, because spores were not found on any of the carcasses that were sampled with electrostatic cloths after chilling. Further research is required to investigate the source of the contamination of the pork trimmings.