Estudio exploratorio de la genotoxicidad de vacunas recombinantes para tuberculosis bovina

The BCG (Bacillus Calmette-Guerin) vaccine for the control of bovine tuberculosis has variable efficacy and the generation and testing of new vaccines is required. For this reason, an exploratory study was carried out to evaluate the genotoxicity of two potential vaccines, recombinant bovine tuberculosis in Holstein Freisan calves with an average age of 9 months, using micronucleated erythrocytes (MNE). Five groups were formed: 1) Saline solution, 2) The vector pVAX1 (Vector without insert), CV), 3) Vaccine Mycobacterium bovis (M. bovis) type 1 (PE11 [VR1]), 4) Vaccine M. bovis type 2 (PPE68 [VR2]), 5) Both vaccines (VR1 + VR2). Five blood samples were taken from each organism: the first one prior to treatment, the second to the fourth sample every 24 hours and the fifth one 90 days after treatment. The samples were analyzed with microscopy and MNE/10,000 erythrocytes were counted. MNE frequencies decreased with age (Kruskall Wallis, 95%). When analyzing the treatments with respect to the control, a lower value of MNE was identified in the VR2 groups and in VR1 + VR2 (P = 0.02). These results appear to have a cytoprotective effect; however, it could be a masked myelosuppressive (cytotoxic) effect, since the frequency of MNE decreases due to myelosuppression. To confirm cytotoxicity, it is to continue the study in younger organisms suggested.