Diagnosis of bovine tuberculosis (bTB) may be confounded by immunological cross-reactivity to Mycobacterium bovis antigens when animals are sensitised by certain nontuberculous mycobacteria (NTMs). Therefore, this study aimed to investigate NTM species diversity in African buffalo (Syncerus caffer) respiratory secretions and tissue samples, using a combination of novel molecular tools. Oronasal swabs were collected opportunistically from 120 immobilised buffaloes in historically bTB-free herds. In addition, bronchoalveolar lavage fluid (BALF; n=10) and tissue samples (n=19) were obtained during post-mortem examination. Mycobacterial species were identified directly from oronasal swab samples using the Xpert MTB/RIF Ultra qPCR (14/120 positive) and GenoType CMdirect (104/120 positive). In addition, all samples underwent mycobacterial culture, and PCRs targeting hsp65 and rpoB were performed. Overall, 55 NTM species were identified in 36 mycobacterial culture-positive swab samples with presence of esat-6 or cfp-10 detected in 20 of 36 isolates. The predominant species were M. avium complex and M. komanii. Nontuberculous mycobacteria were also isolated from 6 of 10 culture-positive BALF and 4 of 19 culture-positive tissue samples. Our findings demonstrate that there is a high diversity of NTMs present in buffaloes, and further investigation should determine their role in confounding bTB diagnosis in this species.

Drug-resistant tuberculosis (DR-TB) remains a major public health problem in South Africa. Gene mu-tations and the genotyping of DR-TB in a rural Eastern Cape Province have not previously been studied. Hence, we sought to detect prevalent mutations linked to DR-TB profiles, identify genetic diversity, and assign lineages. Sputum specimens were obtained from 1157 patients suspected with tuberculosis. They were assayed for rifampin-resistance using Xpert® MTB/RIF.and detection of mutations conferring re-sistance to anti-TB drugs was carried out using GenoType MTBDRplus VER 2.0. Thereafter, 441 isolates were spoligotyped. The most prevalent rifampin resistance-conferring mutations were in rpoB codon S531L. The INH resistant strains, 54.5% had mutations in katG gene at codon S315TB and 24.7% with mutations in inhA gene at codons C-15TB. Furthermore 69.9% strains displayed mutations involving both rpoB and katG genes, while 24.6% strains displayed mutations involving both rpoB and inhA genes. The overall prevalence of heteroresistance was 17.9%. Spoligotyping analysis generated 410 patterns of iso-lates which were found in the international database, with Beijing family being predominant. The diversity of mutations in the study provides information for investigating the evolutional lineages of M. tuberculosis isolates. The recognition frequency of rpoB, katG and inhA mutations in different study areas may help to guide decision‑making about standardization of treatment regimens or individualized treatment in areas where these mutations have been found. This calls for increased drug resistance surveillance and rein-forcement of TB control in this area.