Differential expression of efflux pump genes of Mycobacterium tuberculosis in response to varied subinhibitory concentrations of antituberculosis agents. Issue 2 (March 2015)

• Record Type: Journal Article
• Authors: Garima, Kushal; Pathak, Rakesh; Tandon, Rashmi; Rathor, Nisha; Sinha, Rajesh; Bose, Mridula; Varma-Basil, Mandira
• Is Part Of: Tuberculosis. Volume 95:Issue 2(2015)
• Page Start: 155
• Page End: 161
• Publication Date: 2015-03
• Subjects: 616.995
• DOI: 10.1016/j.tube.2015.01.005
• Languages: English
• ISSNs: 1472-9792

Abstract

<abstract xml:lang="en" abstract-type="author" id="abs0010"> <title id="sectitle0010">Summary</title> <sec> <p id="abspara0010">Several reports have elaborated on the role of efflux pumps in drug resistance in <italic>Mycobacterium tuberculosis</italic> by analysing the mRNA expression profiles. However, there is no uniformity in the subinhibitory concentrations of drugs chosen in these studies. Some investigators studied the expression of efflux pumps under a drug concentration of 1/2 minimum inhibitory concentration (MIC), while others used 1/3, 1/4 or 1/8MIC. The present study was planned to understand the effect of different concentrations of antituberculosis drugs on the expression of efflux pump genes. Log phase culture of the laboratory strain <italic>M. tuberculosis</italic> H37Rv was exposed to rifampicin (RIF), isoniazid (INH), streptomycin (SM) and ethambutol (EMB) at different drug concentrations (1/2MIC, 1/3MIC and 1/4MIC). The expression of 10 putative efflux pump genes was studied using quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). We observed an optimal expression of efflux pumps at higher concentrations of INH; and at lower concentrations of RIF and EMB. However, in the presence of SM, a decreased expression of efflux genes with increasing concentrations of the drug was confounded by a significant reduction in Colony Forming Units (CFU).</p> </sec> </abstract>