Biological Control of Salmonella typhimurium in Young Chickens

Abstract

The effect of dietary lactose and anaerobic cultures of cecal microflora of mature chickens on the colonization of young broiler chickens by Salmonella typhimurium was evaluated. Newly hatched chicks were given either no treatment (controls), anaerobic cecal cultures, lactose (2.5%) in the drinking water, or both anaerobic cultures and lactose. Chicks were challenged per os at 3 days of age with either 10(6) or 10(8) S. typhimurium resistant to nalidixic acid and novobiocin. On day 10, the cecal contents of the chicks were examined for S. typhimurium, pH, short-chained volatile fatty acids (VFAs), undissociated VFAs, and lactic acid. Chicks given either lactose alone or cecal anaerobes alone had significantly (P less than 0.05) fewer S. typhimurium recovered from their ceca than the controls. Chicks given the combination of dietary lactose and cecal anaerobes had significantly fewer S. typhimurium recovered from their ceca than the chicks given dietary lactose or cecal anaerobes alone. Chicks given lactose had significant (P less than 0.05) increases in the lactic acid concentration of their cecal contents. Increased lactic acid concentrations were directly correlated to decreased cecal pH values and caused a reduction in the total concentration of VFAs but a significant (P less than 0.05) increase in the undissociated form of some VFAs.

Subpopulation Characteristics of Egg-Contaminating Salmonella enterica serovar Enteritidis as Defined by the Lipopolysaccharide O Chain

“…There is some molecular evidence that the cecum supports the growth and colonization of subpopulations of Salmonella that vary in LPS O-chain composition, whereas the intestine favors smooth strains (33). Gut physiology can be manipulated, and many types of biological controls and diets have been designed with the idea of excluding pathogenic salmonellae from the gut (6,24,26,27,30,42,50). Refinement of these approaches to suppress the emergence of subpopulations of S. enterica serovar Enteritidis that have tropism for the reproductive tract of the hen might further reduce the number of contaminated eggs that reach the market.…”

Evaluation of the effect of mannan-oligosaccharides on the competitive exclusion of Salmonella Enteritidis colonization in broiler chicks

“…Several approaches have been studied with varying degrees of success. Among suggested approaches, the incorporation of lactose or mannose in the diet have been shown to significantly reduce colonization of the broiler chick's intestinal tract by Salmonella enterica serovar Typhimurium, compared with controls, possibly due to changes in the pH of the intestinal content as a result of changes in volatile fatty acid concentrations (Oyofo et al, 1989;Corrier et al, 1990a,b;Hinton et al, 1990;Corrier et al, 1991).…”

Comparison of the Efficacy of Cultures of Cecal Anaerobes as Inocula to Reduce Salmonella typhimurium Colonization in Chicks with or Without Dietary Lactose

“…Poultry rearing practices that prevent chicks from becoming colonized by these cecal anaerobes make the chicks more susceptible to sahnonellae colonization (Pivnick et al, 1981). Cecal anaerobes may decrease sahnonellae colonization by rapidly colonizing the intestinal tract of the young chicks (Pivnick et al, 1981), by competing for attachment sites on the intestinal wall (Snoeyenbos et al, 1979), or by producing bacteriostatic or bactericidal short-chained volatile fatty acids (VFA) (Barnes et al, 1979(Barnes et al, , 1980Corrier et al, 1990a,b;Hinton et al, 1990) that inhibit the growth of enteropathogens (Meynell, 1963;Bohnhoff et al, 1964b;Barnes et al, 1979;Que et al, 1986;Pongpech and Hentges, 1989).…”