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The goal of the proposed research is to identify and isolate bacteria from the intestinal tract of chickens and to eventually test their effectiveness in reducing colonization of young chicks with Salmonella.
The community of bacteria inhabiting the intestinal tract can prevent or impede the establishment of undesirable bacteria such as Salmonella enterica subspecies. Newly hatched chicks lack an intestinal bacterial community. Exposure to intestinal bacteria from adult chickens potentially heightens the resistance of young birds to infection with Salmonella. Such bacterial preparations can therefore contribute to increased microbial food safety of poultry products by reducing the number of chickens in a flock that carry Salmonella into the processing plant. The optimal composition of an effective bacterial preparation is currently not known. The goal of the proposed research is to identify and isolate bacteria from the intestinal tract of chickens and to eventually test their effectiveness in reducing colonization of young chicks with Salmonella. The research will focus on the bacteria that are associated with the inner surface of one of the chickens intestinal organs, the cecum. Since a considerable fraction of intestinal bacteria has been refractory to isolation in pure culture, the bacteria will initially be identified without culturing, using genetic means. Identification will be achieved by sequencing of16S rRNA genes amplified from total DNA extracted from the cecal bacterial community. Denaturing gradient gel electrophoresis of amplified DNA and in-situ hybridization with specific probes will provide information on the diversity, location and prevalence of bacteria within the ceca. Once the identity of the cecal bacteria is known, culture conditions for their isolation can be designed and their value in prevention of Salmonella carriage in chickens can be assessed.