Saira Salim1, Wajid Hussain2, Gohar Zaman3, Umer Khurshid2, Luqman Satti4. 1. Department of Pathology, DHQ Hospital, Rawalpindi, Pakistan. 2. Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan. 3. Department of Microbiology, Armed Forces Institute of Pathology (AFIP), Rawalpindi, Pakistan. 4. Department of Microbiology, PNS Shifa Hospital, Karachi, Pakistan.
Abstract
OBJECTIVE: To compare the efficacy of Gene Xpert mycobacterium tuberculosis-rifampicin and multiplex polymerase chain reacton for the detection of mycobacterium tuberculosis and Rifampicin resistance. METHODS: The cross-sectional validation study was conducted at the Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from March to October 2018, and comprised mycobacterium tuberculosis-positive rifampicin-resistant and rifampicin-susceptible samples, with the latter acting as negative controls. Gene Xpert mycobacterium tuberculosis-rifampicin assasy and multiplex polymerase chain reacton were applied simultaneously and compared with gold standard mycobacterium growth indicator tube 960. Data was analysed using SPSS 24. RESULTS: Of the 192 samples, 84(44%) were culture-positive rifampicin-resistant and 108(56%) were culture-positive rifampicin-susceptible. Overall, 84(44%) were found positive. Gene Xpert mycobacterium tuberculosis-rifampicin assay detected all 84(100%) rifampicin-resistant samples, while multiplex polymerase chain reacton detected 44(52.3%) such samples. Sensitivity, specificity, positive predictive value and negative predictive value of Gene Xpert were 100% each respectively, while the corresponding values for multiplex polymerase chain reacton were 52%, 100%, 100% and 72% respectively. CONCLUSIONS: Molecular detection of mycobacterium tuberculosis and resistance by Gene Xpert and multiplex polymerase chain reacton simultaneously was found to be a rapid and cost-effective method.
OBJECTIVE: To compare the efficacy of Gene Xpert mycobacterium tuberculosis-rifampicin and multiplex polymerase chain reacton for the detection of mycobacterium tuberculosis and Rifampicin resistance. METHODS: The cross-sectional validation study was conducted at the Department of Microbiology, Armed Forces Institute of Pathology, Rawalpindi, Pakistan, from March to October 2018, and comprised mycobacterium tuberculosis-positive rifampicin-resistant and rifampicin-susceptible samples, with the latter acting as negative controls. Gene Xpert mycobacterium tuberculosis-rifampicin assasy and multiplex polymerase chain reacton were applied simultaneously and compared with gold standard mycobacterium growth indicator tube 960. Data was analysed using SPSS 24. RESULTS: Of the 192 samples, 84(44%) were culture-positive rifampicin-resistant and 108(56%) were culture-positive rifampicin-susceptible. Overall, 84(44%) were found positive. Gene Xpert mycobacterium tuberculosis-rifampicin assay detected all 84(100%) rifampicin-resistant samples, while multiplex polymerase chain reacton detected 44(52.3%) such samples. Sensitivity, specificity, positive predictive value and negative predictive value of Gene Xpert were 100% each respectively, while the corresponding values for multiplex polymerase chain reacton were 52%, 100%, 100% and 72% respectively. CONCLUSIONS: Molecular detection of mycobacterium tuberculosis and resistance by Gene Xpert and multiplex polymerase chain reacton simultaneously was found to be a rapid and cost-effective method.