Evaluation of Multidrug Resistant Loop-mediated Isothermal Amplification Assay for Detecting the Drug Resistance of Mycobacterium tuberculosis

摘要

Objective To evaluate multidrug resistant loop-mediated isothermal amplification(MDR-LAMP)assay for the early diagnosis of multidrug-resistant tuberculosis and to compare the mutation patterns associated with the rpoB,katG,and inhA genes at the Chinese Center for Disease Control and Prevention.Methods MDR-LAMP assay was evaluated using 100 Mycobacterium tuberculosis(Mtb)isolates obtained from the National Reference Laboratory for Tuberculosis in China.Phenotypic resistance to isoniazid and rifampicin and whole-genome sequencing served as reference standards.Results The sensitivity,specificity,positive predictive value(PPV),and negative predictive value(NPV)of MDR-LAMP were 85.5%,93.6%,96.7%,and 74.4%for the detection of resistance to isoniazid and rifampicin,respectively,and 80.5%,92.3%,98.6%,and 41.4%for the detection of Mtb cultured from smear-positive sputum samples,respectively.When DNA sequencing was used as the reference standard,the sensitivity,specificity,PPV,and NPV of MDR-LAMP were 93.1%,92.3%,97.2%,and 82.8%for the detection of katG and inhA gene mutations,respectively,and 89.1%,88.9%,93.4%,and 81.1%for the detection of rpoB gene mutation,respectively.Conclusion MDR-LAMP is a rapid and accessible assay for the laboratory identification of rifampicin and isoniazid resistance of Mtb isolates.