Submitted to: Journal Of Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 13, 1997
Publication Date: N/A
Interpretive Summary: Contamination of poultry meat by Salmonella bacteria is an important source of human food poisoning. Poultry meat may become contaminated with Salmonella during the slaughter process when the birds are going through the processing plant. It is important to identify those places where contamination occurs during the slaughter process and to prevent the contamination from occurring. We discovered, for the first time, that the crop of poultry often contains Salmonella bacteria which contaminate the skin and meat of the chicken and the machinery in the slaughter plant. This discovery is important because now that the crop has been identified as an important source of Salmonella, it can be removed more carefully to prevent contamination of meat and machinery and reduce human exposure to Salmonella infection.
Much previously published research has focused on the role of cecal and intestinal Salmonella contamination of poultry carcasses within commercial processing plants. Presently, we have evaluated the persistence of experimentally inoculated Salmonella enteritidis in the crops and ceca of commercial broiler chickens during the last week of growth (Weeks 6 to 7) and the presence of crop and cecal Salmonella in 7-wk-old broilers in a commercial processing plant. When broilers were inoculated with 1 x 10**6 cfu S. enteritidis at 6 wk of age by oral gavage, the incidence of crop and cecal contamination was equivalent 2 d after challenge (30%), with only 1 of 29 crops contaminated and 0 of 29 ceca contaminated at 7 d following challenge. When broilers were inoculated with 1 x 10**8 cfu S. enteritidis at 6 wk of age by oral gavage, 2 d after challenge the crops and ceca were observed to be 57 and 67% positive for S. enteritidis, respectively. Seven days after inoculation with 1 x 10**8 S. enteritidis, the crops and ceca were 37 and 57% positive, respectively, for the challenge organism. At a commercial broiler processing plant, 286 of 550 crops from three flocks were Salmonella-positive, whereas only 73 of 500 ceca from these flocks were contaminated. Furthermore, data from this plant indicated that the crops were far more likely to rupture than ceca (86-fold) during processing, increasing the possibility of carcass contamination with Salmonella derived from crop contents. The results of these studies suggest that the crop may serve as a source of carcass contamination with Salmonella within some processing plant.