title: Molecular analysis of isoniazid, rifampin and streptomycin resistance in Mycobacterium tuberculosis isolates from patients with tuberculosis in Düzce, Turkey.
abstract: The aim of this study was to use DNA sequencing analysis to analyze the mutations in the most commonly targeted genes (katG, inhA, rpoB, rpsL) in isoniazid (INH)-, rifampin (RIF)- and streptomycin (SM)-resistant Mycobacterium tuberculosis strains obtained from subjects in Duzce, Turkey. Four isolates were found to be INH-resistant, 3 were RIF-resistant and 5 were SM-resistant, out of a total of 52 M. tuberculosis strains. In 3 of the 4 INH-resistant strains, a mutation in the katG gene in codon 315 appeared as AGC-->ACC (Ser-->Thr), and the other INH-resistant strain showed a mutation in the katG gene in codon 314 as ACC-->CCC (Thr-->Pro). There were no mutations in the inhA gene in INH-resistant isolates. Two of the 3 RIF-resistant strains were found to have mutations in the rpoB gene in codon 516 appearing as GAC-->GTC (Asp-->Val), and the other RIF-resistant strain has a mutation in the rpoB gene in codon 531 as TCG-->TTG (Ser-->Leu). These 3 RIF-resistant strains are also INH-resistant. All 5 SM-resistant strains have mutations in the rpsL gene in codon 43 appearing as AAG-->AGG (Lys-->Arg). Thus, we found common gene mutations that bring about the resistance of M. tuberculosis to antituberculosis drugs in all of our isolates from Duzce. To the best of our knowledge, the ACC-->CCC (Thr-->Pro) mutation in the katG gene in codon 314 has not been previously defined.
authors.affiliation: Department of Microbiology, Abant Izzet Baysal University, Düzce School of Medicine, Düzce, Turkey. elifozturk1968@yahoo.com
authors.forename: C Elif
authors.initials: CE
authors.lastname: Ozturk
authors.forename: Ahmet
authors.initials: A
authors.lastname: Sanic
authors.forename: Demet
authors.initials: D
authors.lastname: Kaya
authors.forename: Ismail
authors.initials: I
authors.lastname: Ceyhan
mesh_terms: D019943:Amino Acid Substitution; D000995:Antitubercular Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D001483:Base Sequence; D002374:Catalase / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D012321:DNA-Directed RNA Polymerases; D024881:Drug Resistance, Bacterial / Q000235:genetics; D005798:Genes, Bacterial; D006801:Humans; D066298:In Vitro Techniques; D007538:Isoniazid / Q000494:pharmacology; D009169:Mycobacterium tuberculosis / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D010088:Oxidoreductases / Q000235:genetics; D017354:Point Mutation; D012293:Rifampin / Q000494:pharmacology; D013307:Streptomycin / Q000494:pharmacology; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy / Q000382:microbiology*; D014421:Turkey
chemical_list: D000995:Antitubercular Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; C505805:rpoB protein, Mycobacterium tuberculosis; D010088:Oxidoreductases; D002374:Catalase; C480353:katG protein, Mycobacterium tuberculosis; C085257:InhA protein, Mycobacterium; D012321:DNA-Directed RNA Polymerases; D007538:Isoniazid; D012293:Rifampin; D013307:Streptomycin