Evaluation of cocktails with recombinant proteins of Mycobacterium bovis for a specific diagnosis of bovine tuberculosis

MON, MARIA LAURA; MOYANO, DAMIÁN; VIALE, MARIANA; COLOMBATTI, ALEJANDRA; GAMIETEA, IGNACIO; MONTENEGRO, VALERIA; ALONSO, BERNARDO; SANTANGELO, MARÍA DE LA PAZ; DURAN, ROSARIO; ROMANO, MARÍA ISABEL

BioMed Research International

Hindawi

Año: 2014 p. 1 - 10

The delayed type hypersensitivity skin test (DTH) and the interferon-gamma (IFN-) assay 2 are used for the diagnosis of bovine tuberculosis (TBB). However, the specificity of these 3 tests is compromised because both are based on the response against purified protein 4 derivative of Mycobacterium bovis (PPD-B). In the current study, we assessed the potential of 5 two cocktails containing M. bovis recombinant proteins: Cocktail 1 (C1): ESAT-6, CFP-10 6 and MPB83, and cocktail 2 (C2): ESAT-6, CFP-10, MPB83, HspX, TB10.3 and MPB70. C1, 7 C2 and PPD-B showed similar response by DTH in M. bovis-sensitized guinea pigs. 8 Importantly, C1 induced a lower response than PPD-B in M. avium-sensitized guinea pigs. In 9 cattle, C1 displayed better performance diagnostic than PPD-B and even than C2 by IFN- 10 assay; indeed, C1 detected animals with TBB, and showed the least detection of animals 11 either vaccinated or infected with Map. With the aim of optimizing the composition of the 12 cocktails, we obtained different protein fractions from PPD-B and tested their 13 immunogenicity in experimentally M. bovis-infected cattle. In one highly reactive fraction, 14 seven proteins were identified: MPB70, MPB83, CFP10, CFP2, FixB, PepA and HspX. The 15 inclusion of FixB in C1 enhanced the recognition of naturally M. bovis-infected cattle by IFN-16 assay without compromising specificity. Our data provide a promising basis for the future 17 development of a cocktail for TBB detection without interference by the presence of 18 sensitized or infected animals with other environmental mycobacteria.