Evaluation of reverse transcription loop-mediated isothermal amplification in conjunction with ELISA–hybridization assay for molecular detection of Mycobacterium tuberculosis

Traditional culture, followed by a panel of biochemical tests for the diagnosis of tuberculosis (TB), is time-consuming, and rapid identification of Mycobacterium tuberculosis is crucial for the early administration of appropriate therapy. In this study, the reverse transcription loop-mediated isothermal amplification combined with enzyme-linked immunosorbent hybridization (RT-LAMP–ELISA-hybridization) assay has been designed for the rapid detection of 16S rRNA in clinical isolates of M. tuberculosis. This assay reproducibly detected a single copy, as opposed to 2000 copies of MTB 16S rRNA detected by conventional gel electrophoresis. Among the 150 specimens of sputum analysed, RT-LAMP–ELISA-hybridization assay had a sensitivity of 94.1% in the culture method, compared to the Amplified M. tuberculosis Direct Test (AMTD), 91.1% and the 88.2% sensitivity of acid-fast staining. Furthermore, RT-LAMP–ELISA-hybridization assay is more cost-effective when compared to the real-time TaqMan RT-PCR and AMTD assays. In conclusion, our results suggest that the RT-LAMP–ELISA-hybridization assay is a highly sensitive, low cost diagnostic tool useful for the rapid and accurate direct diagnosis of sputum specimens, and is suitable for routine clinical use.