ARS | Publication request: COMPETITIVE EXCLUSION OF SALMONELLA SEROVAR TYPHIMURIUM FROM THE GUT OF EARLY WEANED PIGS

Submitted to: International Symposium on Epidemiology and Control of Salmonella in Pork
Publication Type: Proceedings
Publication Acceptance Date: August 11, 1999
Publication Date: N/A

Technical Abstract: Strategies to curb infection of pigs by Salmonella, bacteria causing considerable economic losses to the swine industry, are sought throughout the farm to table continuum. Research has shown competitive exclusion to be an attractive strategy for protecting young pigs from infection by Salmonella Choleraesuis, the serotype responsible for most (>90%) of diagnosed cases of swine salmonellosis in the United States. However, sinc Salmonella Typhimurium is a much greater food safety concern than Salmonella Choleraesuis we conducted a study to evaluate the effect of competitive exclusion treatment on colonization of early weaned pigs by Salmonella Typhimurium. Piglets from two litters (n=9 and 6, respectively) were either treated (via oral gavage, 5 ml) at birth and at weaning (14 days of age) with a porcine derived competitive exclusion culture (pCF1) or were left untreated. Culture pCF1, propagated from cecal contents of a healthy pig, was maintained in steady state via continuous-flow culture methodology. One day post weaning, the piglets were challenged orally with 107 colony forming units (CFU) Salmonella Typhimurium. Rectal swabs collected daily and samples (ileocolic lymph nodes and cecal contents) collected upon necropsy 9 days post challenge were cultured for salmonellae. As previously observed in studies using Salmonella Choleraesuis, shedding of Salmonella Typhimurium was reduced within the litter treated with pCF1 compared to the untreated litter (44 versus 77%, respectively). Additionally, Salmonella Typhimurium was recovered from cecal contents of fewer of the pCF1 treated piglets (5 of 9) than from those not treated (6 of 6).