Primary Drug Resistance and Molecular Epidemiology of the Mycobacterium tuberculosis Strains Isolated in the Kelkit Valley

Authors: YUNUS BULUT, GÜLGÜN YENİŞEHİRLİ, BARIŞ OTLU, ZEHRA SEYFİKLİ, SERHAT ÇELİKEL, AYŞE YILMAZ, HANDAN İNÖNÜ

Abstract: Aim: The aim of this study was to determine the primary drug resistance rates and genotypes of resistant Mycobacterium tuberculosis strains isolated in the Kelkit Valley. Materials and Methods: Primary resistance to isoniazid (INH), rifampicin (RIF), ethambutol (ETB), and streptomycin (SM) was determined with the BACTEC 460 radiometric system. Forty-eight resistant M. tuberculosis strains isolated from tuberculosis patients living in the Kelkit Valley were genotyped using the spoligotyping method. Results: Approximately 11.6% of the strains were resistant against at least one major drug, and 8.3% were resistant against more than one drug. Single-drug resistance for INH, ETB, SM, and RIF was found as 5.8%, 2.1%, 3.7%, and 0.0%, respectively. Two or more drug resistance rates for SM + ETB, SM + INH, INH + RIF, RIF + ETB, INH + ETB + RIF, SM + ETB + INH and INH + ETB + RIF + SM were determined as 0.8%, 1.7%, 0.4%, 0.8%, 2.9%, 0.4%, and 1.2%, respectively. Fifteen spoligotype groups were created when the results were compared with the world databank (SpoIDB4). Families of four strains could not be determined. The spoligotype groups most frequently encountered in our study were ST4 (n = 10, 20.8%), ST53 (n = 6, 12.5%), ST7 (n = 4, 8.3%), ST41 (n = 4, 8.3%) and ST31 (n = 4, 8.3%), and the most frequently encountered families were TI (n = 18, 37.5%), S (n = 12, 25%) and LAM-7 TUR (n = 4, 8.3%). Conclusions: High rates of primary resistance against major anti-tuberculosis drugs, the LAM-7 TUR clone, and high grouping rates were detected in this study, the first such study carried out in the Kelkit Valley.

Keywords: M. tuberculosis, primary drug resistance, molecular epidemiology

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