ISSN: 2161-1068
Parisa Farnia, Alireza Javadi*, Shima Seif, Poopak Farnia, Jalaledin Ghanavi
Background: Rapid diagnosis of TB globally remains challenging and emergence of resistant strains represents a significant threat. Improved techniques on diagnosis of tuberculosis is a major concerning for this burden control and is crucial for new tuberculosis control strategy. This study aimed to evaluate diagnostic accuracy of GeneXpert MTB/RIF assay for confirming rifampicin resistance among those suspects comparing to multiplex PCR, RFLP-PCR and real-time PCR amplifications.
Methods: Sputum samples were collected and analysed during 2021 to 2023. Sputum was transferred to the bacteriology laboratory for MTB/RIF detection using conventional bacteriological and molecular based-assays. Sensitivity and specificity were accounted for the stained smear and other molecular methods according to GeneXpert MTB/RIF as the gold standard.
Results: All 93 samples were analyzed for rifampicin resistance by GeneXpert MTB/RIF compared to others, of 73 (78.49%) positive samples, 59 (63.44%) and 17 (18.27%) were positively reported as susceptible and resistance respectively, while 17 (18.27%) negatively reported. The positivity rates, PPV and NPV for microscopy (77.41%, 87%, 76%), real time PCR (78.49%, 84%, 72%), RFLP-PCR (78.49%, 80%, 85%) and multiplex PCR (67.74%, 78%, 56%) respectively. Among those molecular diagnostic techniques, only RFLP-PCR followed by GeneXpert results with the sensitivity and specificity of 96% and 100%, respectively, was reported as the most powerful method compared to others for diagnosis of Mtb and the genome sequence of rifampicin resistance.
Conclusions: Both modern and conventional molecular techniques can be aligned and used together for rapid and conclusive diagnosis of Mtb and rifampicin resistance region, rpoB.
Published Date: 2025-03-20; Received Date: 2024-04-24