title: Kinetics of recA and recX induction in drug-susceptible and MDR clinical strains of Mycobacterium tuberculosis.
abstract: OBJECTIVE
  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.
authors.affiliation: The Foundation for Medical Research, 84-A, R. G. Thadani Marg, Worli, Mumbai 400018, India.
authors.forename: Purva
authors.initials: P
authors.lastname: Bhatter
authors.affiliation: The Foundation for Medical Research, 84-A, R. G. Thadani Marg, Worli, Mumbai 400018, India.
authors.forename: Anirvan
authors.initials: A
authors.lastname: Chatterjee
authors.affiliation: The Foundation for Medical Research, 84-A, R. G. Thadani Marg, Worli, Mumbai 400018, India fmr@fmrindia.org.
authors.forename: Nerges
authors.initials: N
authors.lastname: Mistry
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000096:biosynthesis*; D024881:Drug Resistance, Bacterial; D015870:Gene Expression; D020869:Gene Expression Profiling; D016685:Mitomycin / Q000494:pharmacology; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D011938:Rec A Recombinases / Q000096:biosynthesis*; D012293:Rifampin / Q000494:pharmacology; D015533:Transcriptional Activation
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C430523:RecX protein, Xanthomonas campestris; D016685:Mitomycin; D011938:Rec A Recombinases; D012293:Rifampin
keywords: M. tuberculosis; multidrug resistant; qRT–PCR