EXPLORING INTER-REGULATORY GENE NETWORK DERIVED CANDIDATE GENES IMPARTING RESISTANCE IN MYCOBACTERIUM TUBERCULOSIS

Anti-tuberculosis drug resistance is considered as the main snag in the global elimination of tuberculosis by the end of 2030. One possible explanation to understand its pathogenesis is its inter-connected genome that makes an intricate network to generate the resistance in Mycobacterium tuberculosis (Mtb). Our hypothesis is to analyze the protein-DNA and protein-protein interaction data of Mtb to probe the candidate genes and then evaluate their resistance induction in Mtb against first line anti-TB drugs. The data of genome wide regulator-DNA interaction (Zeng et al., 2012) and global protein-protein interaction (Wang et al., 2010) were analyzed bioinformatically through cytoscape software to identify the candidate genes participating in drug resistance network. These were individually amplified, cloned and transformed into Mtb competent cells to make overexpression strains of these respective genes or (first define in full what is Egfp) eGFP. These strains were then screened with isoniazid (INH) and rifampicin (RIF) to identify their role in regulating drug resistance. Alamar blue dye color change was considered as the marker of resistance imparted by the candidate genes. Only 30 candidate genes were obtained and functionally categorized into small molecule metabolism, intermediate metabolism, information pathway, conserved hypothetical proteins, and cell wall-cell processes through mycrobrowser. After exposing these 30 overexpression strains to various concentrations of INH and RIF, only 7 strains Rv3416, Rv1267, Rv0165c, Rv1129c (metabolism regulatory proteins), Rv2669 (conserved hypothetical protein), Rv2703 (information pathway) and Rv2780 (intermediary metabolism) showed resistance by growing in the presence of 200 µg/ml INH and alamar blue color was not changed. There was absence of growth change and alamar blue color against rifampicin. Our results suggested that these genes might be the regulators of drug resistance network in Mtb. Targeting drug resistance network is a consideration in the development of new anti-TB drugs.