Identification of Nontuberculous Mycobacterium Species by Polymerase Chain Reaction - Restriction Enzyme Analysis (PCR-REA) of rpoB gene in Clinical Isolates

• DOI: 10.4103/ijmy.ijmy_134_24
• Publication Date: 2024-09-15T20:00:37Z
• Authors: Raj Narayan Yadav; Yellanki Yashwant...; Manpreet Bhalla; Ajoy Kumar Verma
• Keywords: nontuberculous mycobacteria; DNA, Bacterial; Male; Mycobacterium Infections, Nontuberculous; India; rpob gene; Nontuberculous Mycobacteria; DNA-Directed RNA Polymerases; Microbiology; Polymerase Chain Reaction; QR1-502; Tertiary Care Centers; Cross-Sectional Studies; Bacterial Proteins; Prohibitins; Humans; Female; restriction enzyme analysis

Background: Nontuberculous mycobacteria (NTM) infections are an emerging global health concern with increasing incidence. Conventional identification methods for NTM species in clinical settings are prone to errors. This study evaluates a newer method, polymerase chain reaction-restriction enzyme analysis (PCR-REA) of the rpoB gene, for NTM species identification. The study identified NTM species in clinical samples using conventional biochemical techniques and compared the results with PCR-REA of the rpoB gene. This cross-sectional study was conducted at a tertiary health-care center in North India over 18 months, analyzing both pulmonary and extrapulmonary samples.

Methods: Two hundred and forty-seven NTM isolates were identified using phenotypic and biochemical methods. The same isolates were subjected to rpoB gene amplification by PCR followed by REA using Msp I and Hae III enzymes.

Results: Conventional methods identified 12 different NTM species (153 slow-growing and 94 rapid-growing), whereas PCR-REA identified 16 species (140 slow-growing, 107 rapid-growing). The Mycobacterium avium intracellulare complex was the most common species isolated. PCR-REA demonstrated higher resolution in species identification, particularly in differentiating within species complexes.

Conclusions: PCR-REA of the rpoB gene proves to be a simple, rapid, and more discriminative tool for NTM species identification compared to conventional methods. This technique could significantly improve the diagnosis and management of emerging NTM infections in clinical settings.