title: Expression analysis of efflux pump genes among drug-susceptible and multidrug-resistant Mycobacterium tuberculosis clinical isolates and reference strains.
abstract: Finding a gene or genes that are involved with multidrug resistance will be useful for finding a new target for the treatment of drug resistant tuberculosis. In this study, we aimed to compare the differences of the expression of 15 putative multidrug efflux pump genes in clinically isolated drug sensitive and multidrug resistant (MDR) Mycobacterium tuberculosis isolates, and reference strains. We found that these genes in the drug-sensitive and MDR M. tuberculosis isolates have similar rates of expressions. However, we found the expression levels of the all the genes are significantly higher in the clinical strains compared to the expression level of genes in the reference strains. In addition to this, it is found that standard strain has lower MIC value for the drugs including streptomycin and rifampin compared to the clinical isolate. We presume that the increase of the gene expression in the clinical strains is due to the exposure of antituberculosis drugs during treatment of patients, which cause constitutive expression of efflux systems, which might increase MIC levels of the major anti-tuberculosis drugs.
authors.affiliation: Microbiology Department, Faculty of Medicine, Ankara University, 06100 Sihhiye-Ankara, Turkey.
authors.forename: Mustafa Kerem
authors.initials: MK
authors.lastname: Calgin
authors.forename: Fikret
authors.initials: F
authors.lastname: Sahin
authors.forename: Buse
authors.initials: B
authors.lastname: Turegun
authors.forename: Devran
authors.initials: D
authors.lastname: Gerceker
authors.forename: Melike
authors.initials: M
authors.lastname: Atasever
authors.forename: Deniz
authors.initials: D
authors.lastname: Koksal
authors.forename: Djursun
authors.initials: D
authors.lastname: Karasartova
authors.forename: Mehmet
authors.initials: M
authors.lastname: Kiyan
mesh_terms: D000995:Antitubercular Agents / Q000494:pharmacology; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D015870:Gene Expression; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D019450:Genes, MDR; D006801:Humans; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D012293:Rifampin / Q000494:pharmacology; D013307:Streptomycin / Q000494:pharmacology; D018088:Tuberculosis, Multidrug-Resistant / Q000382:microbiology*; D014397:Tuberculosis, Pulmonary / Q000382:microbiology*
chemical_list: D000995:Antitubercular Agents; D012293:Rifampin; D013307:Streptomycin