Lactobacillus strategies to reduce Campylobacter jejuni colonization of broiler chickens

Campylobacter jejuni is one of the leading causes of foodborne bacterial illness in the world. The majority of cases of campylobacteriosis are associated with the consumption of raw or undercooked poultry meat or their cross-contamination with other food products. Strategies to reduce the presence of Campylobacter in the poultry supply are underdeveloped. The probiotic Lactobacillus spp. are a viable delivery vehicle for mucosal vaccines due to the Generally Recognized As Safe (GRAS) status. In addition, recombinant lactobacilli present proteins to the mucosal surface and elicit host immune responses. The overall objectives of this research were to 1) colonize broiler chickens with C. jejuni; 2) construct recombinant Lactobacillus for oral delivery of vaccines against C. jejuni; and 3) evaluate the immunogenicity of the recombinant Lactobacillus strains in broiler chickens. To meet these objectives, broiler chickens were orally administered with 109 CFU/mL of C. jejuni NCTC 11168 on d 14, then necropsied on d 21 for direct-plating of the cecal contents. Results indicate successful C. jejuni colonization of the cecal crypts. Lactobacillus strains were engineered to express C. jejuni FlpA Domain II under a promoter fused to a secretion signal with or without an anchoring signal from the mucus-binding protein of Lactobacillus acidophilus NCFM. Additional work must be conducted to evaluate the exterior protein expression and in vivo antigen-immune response within broiler chickens. If successful, the recombinant Lactobacillus strain could be an attractive candidate as a food-grade live vaccine against Campylobacter colonization. In addition, a non-genetically modified delivery approach proposes attachment of C. jejuni FlpA to the cell wall of lactobacilli utilizing one of three cell wall binding domains. Reduction of Campylobacter at the poultry farm decreases the introduction of the bacteria into the retail market and decreases the incidence of campylobacteriosis