Characterization of resistance mutations against first and second line antituberculosis drugs of multi-drug resistant Mycobacterium tuberculosis strains isolated from clinical samples by In house PCR method and comparison of resistance profiles

Abstract

Aim of the study: Multi-drug resistant tuberculosis (MDR-TB) is still an important public problem. Rapid diagnosis of the agent and determination of resistance status are critical in establishing the correct treatment protocol. This study was conducted with the aim of determining resistance mutations against first and second line drugs in MDR-MTB strain isolated from respiratory tract specimens . Material and method: After the subculture of these strains in Löwenstein - Jensen medium, DNA isolation was performed according to the boiling method. DNA isolates were kept at -40 0C until the working day. Primer sequences specific to rpoB, InhA, katG, gyrA, eis and rrs regions were used to determine isoniazid, rifampicin, quinolone and aminoglycoside resistance. Results: The positivity rate of rpoB, InhA, katG, gyrA, eis and rrs in 33 MDR-TB isolates was 27 (81.8 %), 31 (93.9 %), 25 (75.7 %), 25 (75.7 %), 20 (60.6 %) and 14 (60.6 %), respectively. Resistance mutations were not detected in susceptible isolates. Conclusion: According to the data obtained from the study, it was found that fluoroquinolone resistance mutations were higher in isolates defined as MDR-TB by conventional and molecular methods, and in-house PCR method was a useful method for rapid resistance detection.