title: Outer membrane vesicles of Gallibacterium anatis induce protective immunity in egg-laying hens.
abstract: Gallibacterium anatis causes infections in the reproductive tract of egg-laying hens and induce increased mortality and decreased egg production. New prophylactic measures are needed in order to improve animal welfare and production efficiency. Bacterial outer membrane vesicles (OMVs) have previously shown promising results in protection against infections and we hypothesized that OMVs could serve as an immunogen to protect egg-laying hens against G. anatis. To investigate the immunogenic potential of G. anatis OMVs, two in vivo studies in egg-laying hens were made. The trials assessedthe degree of protection provided by immunization with G. anatis OMV against challenge and the IgY responses in serum after immunization and challenge, respectively. A total of 64 egg-laying hens were included in the trials. OMVs for immunization were produced and purified from a high-producing G. anatis ΔtolR mutant. Challenge was done with G. anatis 12656-12 and evaluated by scoring lesions and bacterial re-isolation rates from peritoneum. Finally, levels of OMV-specific IgY in sera were assayed by ELISA. Immunization with OMVs decreased the lesions scores significantly, while the bacterial re-isolation remained unchanged. Furthermore, a high OMV-specific IgY response was induced by immunization and subsequent challenge of the hens. The results strongly indicate that immunization with G. anatis OMVs provides significant protection against G. anatis challenge and induces specific antibody responses with high titers of OMV-specific IgY in serum. The results therefore show great promise for OMV based vaccines aiming at providing protecting against G. anatis in egg-laying hens.
authors: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Electronic address: spor0001@regionh.dk.
authors: Susanne E
authors: SE
authors: Pors
authors: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Electronic address: idajp@sund.ku.dk.
authors: Ida J
authors: IJ
authors: Pedersen
authors: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Electronic address: ragnhild.bager@bio.ku.dk.
authors: Ragnhild Bager
authors: RB
authors: Skjerning
authors: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Electronic address: icnt@sund.ku.dk.
authors: Ida C N
authors: ICN
authors: Thøfner
authors: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Electronic address: gryper@sund.ku.dk.
authors: Gry
authors: G
authors: Persson
authors: Department of Veterinary Disease Biology, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark. Electronic address: miki@sund.ku.dk.
authors: Anders M
authors: AM
authors: Bojesen
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology*; D002645:Chickens; D006090:Gram-Negative Bacteria / Q000502:physiology*; D016905:Gram-Negative Bacterial Infections / Q000517:prevention & control / Q000662:veterinary*; D007136:Immunoglobulins / Q000097:blood; D010058:Oviposition; D011201:Poultry Diseases / Q000097:blood / Q000517:prevention & control*
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001428:Bacterial Vaccines; C016512:IgY; D007136:Immunoglobulins
keywords: Egg-laying hens; Gallibacterium anatis; Immunization; Outer membrane vesicles; Protection