Purva Bhatter1, Anirvan Chatterjee1, Nerges Mistry2. 1. The Foundation for Medical Research, 84-A, R. G. Thadani Marg, Worli, Mumbai 400018, India. 2. The Foundation for Medical Research, 84-A, R. G. Thadani Marg, Worli, Mumbai 400018, India fmr@fmrindia.org.
Abstract
OBJECTIVES: To investigate and compare the expression of recA and recX, components of the SOS pathway, following rifampicin treatment in drug-susceptible and MDR clinical strains of Mycobacterium tuberculosis. METHODS: Strains (M. tuberculosis and Mycobacterium smegmatis) were subjected to rifampicin- and mitomycin-induced stress for 36 h followed by RNA extraction. recA and recX in the RNA extract were estimated using qRT-PCR. RESULTS: The MDR clinical strain induced faster (24 h) and higher (7-fold) levels of recA as compared with the drug-susceptible strain (36 h) in response to rifampicin. recX levels were found to rise with an increase in levels of recA; however, the levels were relatively higher than recA. CONCLUSIONS: Drug-susceptible and MDR strains have different kinetics of induction of DNA repair.
OBJECTIVES: To investigate and compare the expression of recA and recX, components of the SOS pathway, following rifampicin treatment in drug-susceptible and MDR clinical strains of Mycobacterium tuberculosis. METHODS: Strains (M. tuberculosis and Mycobacterium smegmatis) were subjected to rifampicin- and mitomycin-induced stress for 36 h followed by RNA extraction. recA and recX in the RNA extract were estimated using qRT-PCR. RESULTS: The MDR clinical strain induced faster (24 h) and higher (7-fold) levels of recA as compared with the drug-susceptible strain (36 h) in response to rifampicin. recX levels were found to rise with an increase in levels of recA; however, the levels were relatively higher than recA. CONCLUSIONS: Drug-susceptible and MDR strains have different kinetics of induction of DNA repair.