Comparison of mucosal competitive exclusion and competitive exclusion treatment to reduce Salmonella and Campylobacter spp. colonization in broiler chickens

Control of Salmonella spp. during the earliest phases of broiler production may provide the best opportunity to reduce human pathogens on processed br oiler carcasses. Application of the "Nurmi concept" has been demonstrated t o be an effective means in reducing Salmonella colonization among broiler c hicks. In 1989, Aho et al. developed a competitive exclusion (CE) culture f or control of Salmonella spp., whereas a mucosal competitive exclusion cult ure (MCE) developed in the United States was originally created to control Campylobacter colonization (Stern et al., 1995). The major differences in t he two patents were the higher level of anaerobic culture required, the deg ree of epithelial scraping and washing of the ceca, media used for subcultu ring, and the culture incubation temperatures (35 C vs. 42 C). The CE and M CE were compared for efficacy in reducing Salmonella and Campylobacter colo nization in broiler chicks. Nine adult birds (three for each of three repli cates) were slaughtered, and each of a bird's paired ceca were used to prod uce corresponding antagonistic microflora, which were administered to day-o f-hatch chicks. The chicks (a total of 210) were challenged 24 h later with Salmonella and Campylobacter and were killed 1 wk later, and levels of the pathogens were determined. Ninety CE-treated birds were significantly more colonized by Salmonella typhimurium than those 90 chicks treated with the MCE microflora (3.97 log 10 cfu/g cecal contents vs. 1.25 log 10 cfu/g ceca l contents). Also, Campylobacter spp. colonization of these birds was signi ficantly higher for CE-treated birds when compared with MCE-treated birds ( 6.96 log 10 cfu/ g cecal contents vs. 5.03 log 10 cfu/g cecal contents). Th ese results can be useful in developing intervention strategies to reduce c hicken colonization by Salmonella and Campylobacter.