Mycobacterium bovis Δmce2 double deletion mutant protects cattle against challenge with virulent M. bovis

Interleukin-17A as a Biomarker for Bovine Tuberculosis

“…One microgram of RNA was reverse transcribed in a 50-l reaction mixture using SuperScript II (Invitrogen, Carlsbad, CA) with 0.5 g of oligo(dT) [12][13][14][15][16][17][18] and 40 units of RNaseOut (Invitrogen), according to the manufacturer's directions. Samples were heated to 70°C for 5 min and then reverse transcribed at 42°C for 60 min.…”

“…Additional biomarkers have recently emerged as potential candidates for use in blood-based TB tests for humans (reviewed by Walzl et al [5] and Salgame et al [6]) and cattle, including interleukin-1␤ (IL-1␤), IL-2, tumor necrosis factor alpha (TNF-␣), nitric oxide, IL-17, and IFN-␥-induced protein 10 (IP-10) (7)(8)(9)(10)(11)(12)(13). Of these, IL-17 is particularly appealing as a biomarker for bovine TB, as IL-17A mRNA responses determined using real-time quantitative PCR (RT-qPCR) may be predictive of both vaccine efficacy (11,14,15) and lesion severity (7) when measured after vaccination and infection, respectively.…”

Mycobacterium bovis deleted in mce2 and phoP loci protects C57BL/6 mice against tuberculosis

“…When tested in BALB/c mice all vaccine strains, including BCG, have showed a reduced bacterial burden in organs after M. bovis challenge, as compared to non-vaccinated mice [12]. However, MbΔmce2 has also been assessed as experimental vaccine in cattle, showing better protection than BCG [9]. In this study we evaluated the vaccine properties of the double MbΔmce2-phoP mutant in C57BL/6 mice.…”

“…In previous studies we reported the development of a M. bovis strain deleted in the virulence genes mce2A-B, the strain was called MbΔmce2. This strain was superior to BCG to protect cattle against bTB [9] and was unable to produce tuberculosis in cattle [10], which suggests that in cattle this is a safety vaccine. However, the Geneva consensus criteria [11] have established that TB vaccine must be based on two independent stable deletion mutations without antibiotic resistance markers.…”

Immunity and Vaccination against Tuberculosis in Cattle

“…Vaccination with either of two attenuated M. bovis strains derived by UV irradiation, with deletions not defined, produced significant protection against challenge with M. bovis in calves naturally pre-sensitised to environmental mycobacteria, in a study where BCG vaccine was shown to be ineffective [59]. An attenuated M. bovis strain with a double deletion in the mce2 gene was shown to induce significant protection against an M. bovis challenge and induced significantly lower histopathological scores for the lungs and pulmonary lymph nodes compared to that for BCG [66]. Use of the modified BCG strains or RD1 mutants of M. bovis has the advantage that vaccinated animals can be differentiated from M. bovis-infected animals using DIVA tests, while this could not be achieved for those vaccinated with the M. bovis mce2 deletion mutant.…”