title: Expression of a truncated Pasteurella multocida toxin antigen in Bordetella bronchiseptica.
abstract: Mild or subclinical respiratory infections caused by Bordetella bronchiseptica are widespread in pigs despite multiple control efforts. Infection with virulent B. bronchiseptica strains is a common risk factor in the establishment of toxin-producing strains of Pasteurella multocida in the nasal cavity of pigs leading to the disease, atrophic rhinitis (AR). This study was designed to explore the possibility of expressing a protective epitope of P. multocida toxin (PMT) in B. bronchiseptica to create single-component mucosal vaccine to control atrophic rhinitis in pigs. To achieve this, a P. multocida toxin fragment (PMTCE), that was non-toxic and protective against lethal challenge in mice, was cloned into a broad-host-range plasmid, PBBR1MCS2, and introduced into B. bronchiseptica by electroporation. The Pasteurella gene construct was placed under the regulatory control of a promoter region that was separately isolated from B. bronchiseptica and appears to be part of the heat shock protein gene family. B. bronchiseptica harboring the plasmid under antibiotic selection expressed the 80kDa PMTCE as determined by PAGE and Western blot with a PMT-specific monoclonal antibody. When introduced into the respiratory tracts of mice, B. bronchiseptica harboring the plasmid construct was reisolated in declining numbers for 72h post-inoculation. Antibody responses (IgM, IgA and IgG) to B. bronchiseptica were detected in serum and respiratory lavage, but PMTCE-specific antibodies were not detected. While further refinements of PMT expression in B. bronchiseptica are necessary, this study provides a basis for the development of a single-component, live-attenuated vaccine against atrophic rhinitis.
authors.affiliation: Animal Disease Diagnostic Laboratory, Ohio Department of Agriculture, 8995 East Main Street, Reynoldsburg, OH 43068, USA. rajeev@odant.agri.state.oh.us
authors.forename: Sreekumari
authors.initials: S
authors.lastname: Rajeev
authors.forename: Rajeev V
authors.initials: RV
authors.lastname: Nair
authors.forename: Stephen A
authors.initials: SA
authors.lastname: Kania
authors.forename: David A
authors.initials: DA
authors.lastname: Bemis
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D000942:Antigens, Bacterial / Q000096:biosynthesis* / Q000235:genetics / Q000276:immunology; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology*; D001428:Bacterial Vaccines; D016950:Bordetella bronchiseptica / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D003001:Cloning, Molecular; D017931:DNA Primers; D004269:DNA, Bacterial / Q000032:analysis; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D051379:Mice; D008807:Mice, Inbred BALB C; D016979:Pasteurella multocida / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D012222:Rhinitis, Atrophic / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000382:microbiology / Q000517:prevention & control*; D014611:Vaccination / Q000662:veterinary; D014613:Vaccines, Attenuated
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001427:Bacterial Toxins; D001428:Bacterial Vaccines; D017931:DNA Primers; D004269:DNA, Bacterial; D014613:Vaccines, Attenuated