Abstract
Recently identification of mutations responsible for drug resistance by molecular methods are used to detect antimycobacterial resistance in MDR-TB patients and to overcome difficulties of treatment planning in some TB patients. In our study 29 patients were evaluated- 16 patients who were treated with minor therapy or with suspection of MDR-TB and 13 patients with treatment failure, relapsing and returning after defaulting, who were taking retreatment regime. Mutations in rpoB, katG and inhA gene zones specific for rifampicin and isoniazid were investigated with molecular methods in 14 patients from direct smear positive samples and in 15 patients from positive culture. AFB stain, culture and drug susceptibility testing with BACTEC 460 were also done for all samples. 28 samples (22 MDR-TB, 5 susceptible to four drugs, 1 culture negative) were identified as M. tuberculosis complex, 1 patient was detected as M. intracellulare. 27 Patients who were culture positive for MTB were positive with molecular methods, 1 patient who was determined as M. intracellulare was found negative. As compared with drug susceptibility testing, rifampicin resistance was present in all 22 samples (%100) who were determined as MDR-TB and isoniazid resistance was detected in 21 (%95.5) patients. In 5 patients who were susceptible to four drugs, no mutation was found. In 3 patients with HR resistance, cure was achieved with retreatment regime.
Conclusion: The detection of HR resistance with molecular methods is a guide to diagnosis of MDR-TB patients and shortens the time to starting of MDR-TB treatment.
- © 2011 ERS
