title: Characterization and Vaccine Potential of Outer Membrane Vesicles Produced by Haemophilus parasuis.
abstract: Haemophilus parasuis is a Gram-negative bacterium that colonizes the upper respiratory tract of swine and is capable of causing a systemic infection, resulting in high morbidity and mortality. H. parasuis isolates display a wide range of virulence and virulence factors are largely unknown. Commercial bacterins are often used to vaccinate swine against H. parasuis, though strain variability and lack of cross-reactivity can make this an ineffective means of protection. Outer membrane vesicles (OMV) are spherical structures naturally released from the membrane of bacteria and OMV are often enriched in toxins, signaling molecules and other bacterial components. Examination of OMV structures has led to identification of virulence factors in a number of bacteria and they have been successfully used as subunit vaccines. We have isolated OMV from both virulent and avirulent strains of H. parasuis, have examined their protein content and assessed their ability to induce an immune response in the host. Vaccination with purified OMV derived from the virulent H. parasuis Nagasaki strain provided protection against challenge with a lethal dose of the bacteria.
authors.affiliation: Virus and Prion Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA, United States of America.
authors.forename: William D
authors.initials: WD
authors.lastname: McCaig
authors.affiliation: Virus and Prion Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA, United States of America.
authors.forename: Crystal L
authors.initials: CL
authors.lastname: Loving
authors.affiliation: Virus and Prion Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA, United States of America.
authors.forename: Holly R
authors.initials: HR
authors.lastname: Hughes
authors.affiliation: Virus and Prion Diseases Research Unit, National Animal Disease Center, Agricultural Research Service, USDA, Ames, IA, United States of America.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Brockmeier
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology / Q000302:isolation & purification; D001428:Bacterial Vaccines / Q000276:immunology* / Q000302:isolation & purification; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D000067128:Extracellular Vesicles / Q000276:immunology*; D006192:Haemophilus Infections / Q000097:blood / Q000276:immunology / Q000517:prevention & control*; D044137:Haemophilus parasuis / Q000276:immunology*; D016676:Macrophages, Alveolar / Q000276:immunology / Q000378:metabolism; D059748:Proteolysis; D034421:Sus scrofa; D014158:Transcription, Genetic; D014611:Vaccination
chemical_list: D000907:Antibodies, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; D016207:Cytokines