Comparative Analysis of Multi-Drug Resistance in Mycobacterium Tuberculosis Utilizing MTB XDR Assay and Phenotypic Culture Drug Susceptibility Testing (DST) In Azad Jammu & Kashmir
Year: 2026
Type: article
Abstract: Background: Mycobacterium tuberculosis (MTB) is one of the leading causes of morbidity and mortality globally, particularly in low- and middle-income countries Multiple-drug-resistant tuberculosis is still a significant global health issue facing modern medicine, highlighting the need for accurate identification of drug resistance. So, this study aims to compare and evaluate the diagnostic performance of the molecular XDR-TB assay and phenotypic DST. Objective: This study aimed to compare the diagnostic performance of the GeneXpert MTB/XDR assay and phenotypic Drug Susceptibility Testing (DST) for detecting drug-resistant Mycobacterium tuberculosis. Methods: A cross-sectional comparative study was conducted at the State TB Reference Laboratory, Divisional Headquarters Teaching Hospital Mirpur, AJK. A total of 300 culture-confirmed clinical isolates of Mycobacterium tuberculosis, collected from December 16, 2024, to October 13, 2025, from PMDT sites in Muzaffarabad and Mirpur, AJ&K, were analyzed. Initial screening was performed using fluorescence microscopy, followed by confirmation with GeneXpert. Drug resistance was assessed using XDR-TB molecular assay and phenotypic drug susceptibility testing (DST) for first- and second-line anti-tuberculosis drugs. Results: Out of the 300 clinical samples analyzed, 3.3% (10/300) were identified as multidrug-resistant tuberculosis (MDR-TB), and all MDR-TB isolates were also resistant to rifampicin. Among the MDR-TB isolates, 60% (6/10) exhibited resistance to isoniazid, while 40% (4/10) showed resistance to fluoroquinolones. Resistance to amikacin, ethionamide, and pyrazinamide was detected in 10% (1/10) of the MDR-TB isolates for each drug. A high level of concordance was observed between the molecular XDR-TB assay and phenotypic drug susceptibility testing (DST) for the detection of isoniazid and fluoroquinolone resistance. However, discrepant results were observed for amikacin, ethionamide, and pyrazinamide, where the molecular assay identified resistance in one isolate that was not confirmed by phenotypic DST. Conclusion The XDR -TB assay offered more comprehensive information on secondary line drug resistance and showed quicker detection of isoniazid and rifampicin resistance. Molecular XDR -TB assay demonstrated improved sensitivity for identifying specific secondary line drug resistance while exhibiting strong agreement with phenotypic approaches for major first-line medicines.
DOI: 10.65035/php3je20
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
OpenAlex ID: W7213367651