PRODUCTION AND SEROLOGIC EVALUATION OF A BACTERIN AGAINST BOVINE LEPTOSPIROSIS

Objective. To produce a bacterin against bovine leptospirosis. Materials and methods. The production of bacterin was made using the serovares: L. pomona, L. grippotyphosa, L. hardjobovis, L. hardjoprajitno, L. icterohaemorrhagiae and L. canicola with concentrations between 1x108 and 1x1010 cells/ml. Leptospiras were immobilized with formaldehyde and adsorption of aluminum hydroxide to formulate the vaccine. Final concentration of each serovar was of 1x108 Leptospiras/ml. A population of 20 healthy calves bleeding before and after vaccination was immunized to analyze serum evaluation of the biological product to make titrations of serums by means of micro-agglutination technique and this way to determine antibodies production generated by bacterin. Results. L. icterohaemorrhagiae was the serovar with higher titres of antibodies followed by L. canicola. Serums from bleeding made 15 days before revaccination were those with higher number of antibodies for all serovars except for L. grippotyphosa that was the only one that did not stimulate antibodies production in vaccinated animals. Conclusions. The bacterin was able to induce a humoral response in bovines, however, L. grippotyphosa was not immunogen compared with other serovars that participated in the vaccine.