Poster Presentation The Prato Conference on the Pathogenesis of Bacterial Infections of Animals 2016

Innocuousness and immune response of young bulls vaccinated with S19 either subcutaneously or conjunctival (#66)

Guillermo Meglia 1 , Marcelo Gastaldo 1 , Dante Cerutti 1 , J├ęsica Sanchez 1 , Pablo Remirez 1 , Lorena Fernandez 1 , Claudia Tortone 1
  1. National University of La Pampa, Faculty of Veterinary Sciences, General Pico, LA PAMPA, Argentina

Brucellosis is a zoonotic, worldwide distribution, contagious disease that affects ruminants among other species. Since decades Argentina has a nationwide bovine brucellosis control programme, vaccinating female calf aged 3 to 8 months with S19, nevertheless, the outcome still is not promising. New findings in the pathogenesis of the disease encouraged to recheck the programme, where a significant population of animals are not protected (bulls). The objective of the present trial was to determine the kinetic of reproductive tissue colonisation and humoral immune response of bulls vaccinated with S19 either subcutaneously or conjunctival. Thirty bulls were allotted into one of the three groups (n=10/group), Control (Cn), Conjunctival (Cj) and Subcutaneous (Sc). At time zero, the animals were vaccinated, and bled six times, every two months, to assess the humoral immune response. At the time of sampling, semen, epididymis and testicle samples were taken from one animal per group for microbiology and histopathology analysed. The blood concentrations of immunoglobulin were significantly higher (p<0,05) in the Sc group in relation to the Cn and Cj groups. Regardless of the groups and time, all semen, epididymis and testicle samples were negative to bacteriology and histopathology analyses. In conclusion, the serum immunoglobulin titles were higher and persisted for a longer period of time in the Sc group in relation to the Cj group; and none of the vaccinated animals (Sc and Cj) were positive to bacteriological and histopathology determination indicating not reproductive tissue colonisation.