INHIBITION OF SALMONELLA-ENTERITIDIS CECAL AND ORGAN COLONIZATION IN LEGHORN CHICKS BY A DEFINED CULTURE OF CECAL BACTERIA AND DIETARY LACTOSE

The effect of oral inoculation with a defined culture of cecal bacteri a and provision of dietary lactose on colonization resistance to invas ive Salmonella enteritidis was evaluated in leghorn chicks. A defined mixed culture composed of 11 indigenous cecal bacteria capable of util izing lactose or lactose fermentation products as a primary carbon sou rce was isolated and maintained in continuous-flow culture. Combined t reatment with the defined culture and dietary lactose significantly de creased (P < 0.01) the number of Salmonella in the cecal contents and the number of Salmonella cecal-culture-positive chicks in four replica ted trials. Additionally, Salmonella colonization of the spleen, liver , and cecal tonsils was significantly decreased (P < 0.05) in each of the trials. The results indicate that the resistance of leghorn chicks to S. enteritidis cecal and organ colonization is effectively increas ed by inoculation with a defined culture of cecal bacteria and provisi on of lactose in the diet.