Pathogenomics and eco-epidemiology of Mycobacterium orygis, an emerging zoonotic tuberculosis organism

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To investigate the pathogenomics of Mycobacterium orygis, an emerging zoonotic tuberculosis (TB) pathogen, we conducted a comparative whole genome analysis of M. orygis isolates that we had obtained. Our findings suggest that M. orygis has developed unique pathogenic strategies that are differ from other members of M. tuberculosis complex. For instance, unlike in M. bovis, there is a different mutation pattern in the anti-Sigk of M. orygis, leading to higher production of mpt70 and mpt83 immunogenic proteins. Furthermore, polymorphisms in gyrB, mmpL6, PPE55, Rv2042c, TbD1 were identified to be M. orygis specific. These genetic characteristics offer the potential for the development of rapid diagnostic methods for the specific detection of M. orygis. We are continuing our in-depth whole genome analysis of our M. orygis isolates by carefully scruntinizing each single nucleotide polymorphisms, insertion and deletion, and genetic recombination to determine their association with M. orygis.We have developed a fecal mycobacterial assay that uses magnetic beads to capture TB DNA, which can later be detected by the LAMP method. When we validated in a field setting in Nepal, we detected TB bacteria in two TB-seropositive elephants. We have isolated four M. tuberculosis isolates from the culture of postmortem TB-suspected lung tissue samples of four captive elephants. We have collaborated for the surveillance of zoonotic TB in Nepal. However, we were unable to detect M. orygis and other zoonotic TB bacteria from human tuberculosis suspected samples in Nepal.