title: Oral administration of heat-inactivated Mycobacterium bovis reduces the response of farmed red deer to avian and bovine tuberculin.
abstract: Orally delivered mycobacterial antigens may not sensitize the immunized animals causing a positive tuberculin skin test response. As the first step to address this critical issue, we characterized the response of farmed red deer (Cervus elaphus) to orally delivered heat-inactivated Mycobacterium bovis. Thirty-two adult red deer hinds from a farm known to be free of tuberculosis (TB) were randomly assigned to two different treatment groups, immunized (n=24) and control (n=8). Immunized hinds were dosed orally with 2 ml of PBS containing 6 × 10(6) heat-inactivated M. bovis. The mean skin test response of immunized deer to both avian purified protein derivative (aPPD) and bovine PPD (bPPD) was consistently lower in immunized than in control hinds. One year after immunization, immunized hinds had a significant reduction in the skin test response to aPPD and in the ELISA antibody levels against both aPPD and bPPD (24-36% reduction; P<0.05). By contrast, no significant change was observed in the skin test response to phytohaemagglutinin, or in the ELISA antibody levels against the M. bovis specific antigen MPB70. The mRNA levels for C3, IFN-γ and IL-1β and serum protein levels for IFN-γ and IL-1β did not vary between immunized and control deer. However, serum C3 protein levels were significantly higher (P=0.001) in immunized than in control deer six months after immunization. These results confirm that oral heat-inactivated M. bovis does not sensitize farmed red deer and therefore does not cause false-positive responses in the tuberculin skin test. The absence of sensitization in orally immunized deer opens the possibility of testing the vaccine in deer and possibly other ruminants without the risk of causing false-positive reactions in TB-tests. This study also provided the first evidence that orally-delivered inactivated mycobacterial antigens elicit some kind of immune response in a ruminant.
authors.affiliation: SaBio, Instituto de Investigación en Recursos Cinegéticos IREC CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain.
authors.forename: Vladimir
authors.initials: V
authors.lastname: López
authors.affiliation: SaBio, Instituto de Investigación en Recursos Cinegéticos IREC CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain.
authors.forename: David
authors.initials: D
authors.lastname: González-Barrio
authors.affiliation: SABIOtec spin off, Edificio Polivalente UCLM, Camino de Moledores s.n., 13005 Ciudad Real, Spain.
authors.forename: José Francisco
authors.initials: JF
authors.lastname: Lima-Barbero
authors.affiliation: Departamento Veterinario, Cinegético e Investigación de Medianilla S.L., Cádiz, Spain.
authors.forename: José Antonio
authors.initials: JA
authors.lastname: Ortiz
authors.affiliation: Centro de Vigilancia Sanitaria Veterinaria (VISAVET), Universidad Complutense de Madrid, Madrid, Spain.
authors.forename: Lucas
authors.initials: L
authors.lastname: Domínguez
authors.affiliation: NEIKER-Tecnalia, Instituto Vasco de Investigación y Desarrollo Agrario, Departamento de Sanidad Animal, Vizcaya, Spain.
authors.forename: Ramón
authors.initials: R
authors.lastname: Juste
authors.affiliation: NEIKER-Tecnalia, Instituto Vasco de Investigación y Desarrollo Agrario, Departamento de Sanidad Animal, Vizcaya, Spain.
authors.forename: Joseba M
authors.initials: JM
authors.lastname: Garrido
authors.affiliation: NEIKER-Tecnalia, Instituto Vasco de Investigación y Desarrollo Agrario, Departamento de Sanidad Animal, Vizcaya, Spain.
authors.forename: Iker A
authors.initials: IA
authors.lastname: Sevilla
authors.affiliation: SaBio, Instituto de Investigación en Recursos Cinegéticos IREC CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain.
authors.forename: Pilar
authors.initials: P
authors.lastname: Alberdi
authors.affiliation: SaBio, Instituto de Investigación en Recursos Cinegéticos IREC CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain; Department of Veterinary Pathobiology, Center for Veterinary Health Sciences, Oklahoma State University, Stillwater, OK 74078, USA.
authors.forename: José
authors.initials: J
authors.lastname: de la Fuente
authors.affiliation: SaBio, Instituto de Investigación en Recursos Cinegéticos IREC CSIC-UCLM-JCCM, Ronda de Toledo s/n, 13005 Ciudad Real, Spain. Electronic address: christian.gortazar@uclm.es.
authors.forename: Christian
authors.initials: C
authors.lastname: Gortázar
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D002417:Cattle; D016207:Cytokines / Q000378:metabolism; D003670:Deer / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005189:False Positive Reactions; D009163:Mycobacterium bovis / Q000276:immunology*; D014373:Tuberculin / Q000276:immunology; D014374:Tuberculin Test / Q000662:veterinary*; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D016207:Cytokines; D014373:Tuberculin; D015164:Vaccines, Inactivated
keywords: Animal tuberculosis; Complement component 3; Intradermal tuberculin test; Ruminants; Serum antibodies