Skutecznosc natywnej i inaktywowanej leukotoksyny Mannheimia haemolytica w immunoprofilaktyce swoistej syndromu oddechowego owiec

The purpose of this study was to compare the immunostimulating properties and prophylactic effects of native M. haemolytica leukotoxin (Lkt) which was inactivated by formaldehyde and glutaraldehyde. The study also estimated the neutralizing properties of antibodies induced by different forms of Lkt and their protective effects on experimental challenge in sheep. The results of the study suggest that the inactivation procedure has an important effect on immunogenic obtained toxins. Vaccines used in the immunized animals demonstrated an immunogenic presence which was observed in an increase of the specific antibody titers in sera following immunization. An increase in the neutralizing properties of antibodies contained in the sera of animals immunized by Lkt was also observed. The obtained results indicate the possibility of a more effective use of M. haemolytica Lkt isolated from bovine respiratory syndrome as a subunit of the vaccines already used in immunoprophylaxis of this disease in sheep.