Mycobacterium Tuberculosis Strain Lineage in Mixed Tribal Population Across India and Andaman Nicobar Island

Abstract In India, the tribal population constitutes almost 8.6% of the nation’s total population. This study attempts to provide information pertaining to the TB strain diversity, its public health implications, and distribution among the tribal population in 10 Indian states and Andaman & Nicobar (A&N) Island. Clinical isolates were received from 66 villages (10 states and island). A total of 78 M. tuberculosis clinical isolates were received from 10 different states and A&N Island. Among these, 16 different strains were observed. The major M. tuberculosis strains spoligotype belong to the Beijing, CAS1_DELHI, and EAI5 family followed by EAI1_SOM, EAI6_BGD1, LAM3, LAM6, LAM9, T1, T2, U strains. Drug-susceptibility testing (DST) results showed almost 15.4% of clinical isolates found to be resistant to isoniazid (INH) or rifampicin (RMP) + INH. Predominant multidrug-resistant tuberculosis (MDR-TB) isolates seem to be Beijing strain. Beijing, CAS1_DELHI, EAI3_IND, and EAI5 were the principal strains infecting mixed tribal populations across India. Despite the small sample size, this study has demonstrated higher diversity among the TB strains with significant MDR-TB findings. Prevalence of Beijing MDR-TB strains in Central, Southern, Eastern India and A&N Island indicates the transmission of the TB strains.