BHUBANESWAR : In a major step towards elimination of tuberculosis, scientists at the Institute of Life Sciences (ILS) have conducted sequencing of tuberculosis genomes which will help predict drug resistant TB and improve diagnostic and therapeutic approaches.
Conducted in collaboration with RMRC-Bhubaneswar for the first time in Odisha and Northeast states, the study on genetic diversity, evolution, transmission pattern and drug resistance development provides molecular level insight into mycobacterium tuberculosis (MTB) strains of eastern region in comparison with Indian and global perspective.
Although the drug-susceptible cases had a higher treatment success rate, the multi-drug resistance (MDR) and extensively drug-resistant TB (XDR TB) cases have a treatment success rate of only 54 pc and 30 pc, respectively. The major challenge with the current TB diagnostic strategies is the time required for culture-based tests (three to six weeks) and commercially available molecular diagnostics fail to account for novel compensatory mutations leading to drug resistance development.
In the recent study, scientists sequenced 118 culture-positive MTB whole genomes, which include seven follow-up samples, collected from 111 patients in Odisha, Sikkim and Meghalaya. While the samples from Odisha mostly consist of drug-susceptible samples, those from northeast were a mix of MDR and XDR samples as fluoroquinolone resistance is highly prevalent in the region.
The researchers extensively studied the genomic diversity of fluoroquinolone resistant lineage 2 strains along with lineage 1 and lineage 3 strains. They detected a total 12,926 high-quality single nucleotide variants and observed a drastic difference between the lineage distribution of MTB in the Northeast region and Odisha. The lineage-1, also known as Indo Oceanic lineage, is more prominent in Odisha and lineage-2 also known as Beijing lineage has a very dominant presence in the Northeast.
A senior scientist of ILS Dr Sunil Raghav said the study has provided a great opportunity for developing and improving diagnostic and therapeutic approaches.