Mycobacteria Presence and Anti-Tuberculosis Drug Resistance Profile in Düzce Region: 18 Years of Experience

Aim: The aim of this study was to determine the frequency of Mycobacterium tuberculosis complex (MTBC) and non-tuberculous mycobacteria (NTM) growth among mycobacterial isolates collected over 18 years from patients suspected of having tuberculosis, and to evaluate the resistance rates of MTBC strains to first-line anti-tuberculosis drugs. Material and Methods: A total of 17,199 clinical specimens, sent to the Mycobacteriology Laboratory, Department of Medical Microbiology, at Düzce University Health Application and Research Centre between 2004 and 2021 for suspected tuberculosis, were retrospectively analyzed in this study. To differentiate MTBC from NTM, the TBC Identification Test was performed to detect the MPT64 antigen of the MTBC. Ehrlich-Ziehl-Neelsen (EZN) staining method was used to detect the presence of acid-fast bacilli (AFB). Results: Out of the samples with suspected tuberculosis, mycobacterial growth was detected in 896 (5.2%) cases. Among these, 824 (91.9%) were identified as MTBC, while 72 (8.1%) were classified as NTM. EZN staining revealed that 404 (45.1%) out of the 896 isolates were found AFB positive. Analysis of first-line anti-tuberculosis drug susceptibility in the 824 MTBC isolates revealed that 194 were resistant to at least one first-line anti-tuberculosis drug. Of these, 135 isolates showed resistance to a single drug, while 59 exhibited resistance to more than one drug. Conclusion: Tuberculosis remains a significant public health problem both globally and in Türkiye. Regular investigation of local and regional growth patterns and resistance profiles is crucial for achieving the goals of tuberculosis elimination and eradication.