Prevalence, Strains, and Drug Susceptibility of Nontuberculous Mycobacteria Isolates from Tuberculous Suspects

Background: The prevalence of nontuberculous mycobacteria (NTM) infection has been increasing globally. Many cases NTM are misdiagnosed as Mycobacterium tuberculous (MTB) because similar clinicoradiological features. Objectives: To determine the burden and characteristics infection, this study was done to evaluate clinical isolates collected from (TB) suspects in a population Northwest China. Methods: From January December 2020, samples 9,142 TB were for PCR-fluorescent probe mycobacterial culture. probe-positive nucleic acid further subjected DNA microarray confirmation species identification. Drug susceptibility testing (DST) also carried out using micropore plate method (MicroDSTTM) on patients. Results: Of 9,412 suspects, 85 (0.9%) clinically diagnosed with according American Thoracic Society (ATS) guidelines. For laboratory samples, total 169 strains, identified by molecular biology methods, classified into 10 species. most common M. chelonae/ abscessus (64/169, 37.7%) intracellulare (40/169, 23.7%). All strains showed highest resistance imipenem/cilastatin (85/85, 100%) linezolid (4/85, 4.7%). In comparison rapidly growing (RGM) group, slowly (SGM) group lower shorter hospital inpatient stay (t = 6.66, P < 0.001 t 2.40, 0.020, respectively). Conclusions: chelonae/M. frequently detected pathogens differences drug sensitivity giant different strains. Timely identification accurate DST play important roles management.