title: Construction of an attenuated Salmonella delivery system harboring genes encoding various virulence factors of avian pathogenic Escherichia coli and its potential as a candidate vaccine for chicken colibacillosis.
abstract: An attenuated Salmonella (deltalon, deltacpxR, and deltaasdA16) delivery system containing the genes encoding P-fimbriae (papa and papG), aerobactin receptor (iutA), and CS31A surface antigen (clpG) of avian pathogenic Escherichia coli (APEC) was constructed, and its potential as a vaccine candidate against APEC infection in chickens was evaluated. The birds were divided into three groups designated group A (nonvaccinated control), group B (given a single immunization), and group C (administered prime and boost immunizations). Prime and booster vaccinations with the constructions were administered to 1-day-old and 14-day-old birds, respectively. Immune responses were measured postimmunization, and the birds were challenged via an intra-air sac route with a virulent APEC strain at the second, third, and fourth weeks of age. Group B birds were partially protected against the challenge and showed increased levels of plasma immunoglobulin (Ig)G, mucosal IgA antibodies, and lymphocyte proliferation. Group C birds showed greater protection against the challenge, with significantly stronger immune responses compared with the birds in the other groups. Overall, our data suggest that the Salmonella delivery system with recombinant constructs is capable of inducing robust immune responses and induces effective protection against colibacillosis caused by APEC.
authors.affiliation: College of Veterinary Medicine and Bio-Safety Research Institute, Chonbuk National University, Jeonju 561-756, Republic of Korea.
authors.forename: Atul A
authors.initials: AA
authors.lastname: Chaudhari
authors.forename: Kiku
authors.initials: K
authors.lastname: Matsuda
authors.forename: John Hwa
authors.initials: JH
authors.lastname: Lee
mesh_terms: D000818:Animals; D002645:Chickens; D016503:Drug Delivery Systems / Q000662:veterinary; D004926:Escherichia coli / Q000276:immunology*; D004927:Escherichia coli Infections / Q000276:immunology / Q000662:veterinary*; D029968:Escherichia coli Proteins / Q000276:immunology; D022361:Escherichia coli Vaccines / Q000008:administration & dosage / Q000276:immunology*; D011201:Poultry Diseases / Q000276:immunology*; D012486:Salmonella typhimurium; D014170:Transformation, Genetic; D014613:Vaccines, Attenuated / Q000008:administration & dosage / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology; D037521:Virulence Factors / Q000276:immunology
chemical_list: D029968:Escherichia coli Proteins; D022361:Escherichia coli Vaccines; D014613:Vaccines, Attenuated; D014614:Vaccines, Synthetic; D037521:Virulence Factors