Investigation of Trends in Tuberculosis Drug Resistance in Türkiye

Purpose: The emergence of drug-resistant Mycobacterium tuberculosis complex (MTC) strains poses a significant challenge to global tuberculosis (TB) control efforts. This study aimed to evaluate the trends of primary resistance to first-line anti-tuberculosis drugs among clinical MTC isolates obtained in Türkiye over an eight-year period.Methods: This retrospective study included 408 culture-confirmed MTC isolates collected between 2017 and 2024. Drug susceptibility testing for isoniazid (INH), rifampicin (RIF), ethambutol (EMB), and streptomycin (SM) was performed using the Sensititre MYCOTB MIC plate method. Resistance patterns were analyzed according to demographic characteristics and time period.Results: Resistance to at least one first-line drug was detected in 19.3% of isolates. The highest resistance rate was observed for SM, followed by INH, RIF, and EMB. Multidrug-resistant TB (MDR-TB), defined as resistance to both INH and RIF, was detected in 4.16% of cases. Drug resistance was significantly associated with patient age (p 0.05), whereas no significant relationship was found with gender. Resistance rates were higher during the COVID-19 pandemic period, although the difference was not statistically significant.Conclusion: Primary resistance among MTC strains remains an ongoing concern in Türkiye. Continuous monitoring of resistance patterns is essential to support effective treatment strategies and tuberculosis control programs.