Elimination of ESAT-6 and CFP-10 from a candidate vaccine against bovine tuberculosis impaired its protection efficacy in the BALBc mouse model

ELIZABETH GARCIA; FEDERICO BLANCO; FERRARA MUÑIZ, XIMENA; EIRIN, MARIA EMILIA; KLEPP, LAURA INES; BIGI, FABIANA

International Journal of Mycobacteriology

wolters kluwer medknow publications

Año: 2020 vol. 9 p. 417 - 421

2212-5531

Bovine tuberculosis (bTB) is a zoonotic disease caused by Mycobacterium bovis that mainly affects cattle. Althoughvaccination is the most effective strategy to control bTB, it may interfere with the diagnosis of the infection. Therefore, ancillarytests to differentiate vaccinated from infected animals (DIVA) are essential in a cattle vaccination scenario. ESAT-6 and CFP-10 arethe most promissory DIVA antigens. Method: In this study, we deleted esat6 and cfp10 genes from the M. bovis Δ mce2 liveattenuated vaccine candidate and evaluated its protection level against bTB in BALBc mice. Results: We found that the M. bovisstrain mutant in mce2, esat-6 and cfp-10 failed to confer protection against virulent M. bovis challenge in a mouse model oftuberculosis. Conclusions: This result highlights the relevant role of ESAT-6 and CFP-10 in the induction of protective immuneresponse against M. bovis infection and reveals the need of evaluating different strategies to compensate for the lack of theseDIVA antigens in new vaccine formulations.