Species diversity and clinical relevance of nontuberculous mycobacterium isolated from pulmonary and extrapulmonary samples in southeastern Turkey, 2014 to 2023: A retrospective cross-sectional study.

Infection with nontuberculous mycobacterium (NTM) has been on the rise worldwide. Although the incidence rate of NTM infection has increased, little is known about its species diversity and clinical significance. Investigating the variety and load of NTM species in pulmonary and extrapulmonary clinical isolates from a community in southeast Turkey is the goal of this study. The prevalence of NTM and the clinical significance of pulmonary NTM (PNTM) are evaluated in this cross-sectional study. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) and multiplex PCR were used to identify NTM species. Between 2014 and 2023, a total of 30,539 clinical samples from 14,586 tuberculosis (TB)-suspected patients were analyzed. Among the 1159 mycobacterial isolates, 85.25% were identified as Mycobacterium tuberculosis complex (MTBC), while 14.75% were identified as NTM. Of the NTM isolates, 88.88% were pulmonary, while 11.11% were extrapulmonary. The majority of NTM isolates consisted of slow-growing species (67.84%). MTBC rate has decreased while the NTM rate has increased over the years. Of the 171 NTM isolates, identification was performed for 66 isolates. Overall, 16 different NTM species were identified. The most frequently isolated species were Mycobacterium simiae 28.78% (19/66), Mycobacterium avium complex 21.21% (14/66), and Mycobacterium abscessus complex 13.63% (9/66). Among the 66 patients with NTM isolation, the mean age was 39 (±23.10). On applying the American Thoracic Society/Infectious Disease Society of America (ATS/IDSA) criteria to determine the clinical relevance of the 61 patients with PNTM isolation, only 36.06% had nontuberculous mycobacterial pulmonary disease (NTMPD), and the majority were caused by M. simiae (40.9%). Chronic obstructive pulmonary disease was significantly more common in the American Thoracic Society criteria -positive group (22.7%, P = .004). Nodular bronchiectatic patterns occurred significantly more often in the American Thoracic Society criteria-positive group (77.3%, P <.001). A statistically significant correlation was determined between NTMPD and fatigue, although fatigue was not specific for a diagnosis of NTMPD. Cough was the predominant symptom. In conclusion, our findings indicate that the species diversity of NTM isolates in our region differs from that observed in other cities across Turkey. M. simiae emerged as the species with the highest isolation frequency and clinical significance.