Development of a loop-mediated isothermal amplification assay for the rapid detection of six common respiratory...

Due to the highly contagious and spreads quickly of respiratory infectious diseases (ADR), the availability of rapid, sensitive, and reliable diagnostic methods is essential for disease control. Here, we develop an approach based on loop-mediated isothermal amplification (LAMP) for the detection of influenza A virus (Flu A), Flu A subtypes H1N1and H3N2, influenza B virus (Flu B), respiratory syncytial virus (RSV) subtypes A and B, human adenovirus (HAdV), parainfluenza virus (PIV) subtypes 1 and 3, and human rhinovirus (HRV) simultaneously. We designed primers specific to detect respiratory viruses above, optimized the RT-LAMP assay and evaluated it for its sensitivity and specificity of detection using real-time monitoring based on SYBR Green I. We also evaluated the result of our RT-LAMP assay on 638 nasopharyngeal swab specimens with the commercial RT-PCR by Cohen's Kappa. The inconsistent results were verified by Sanger sequencing furtherly. The developed RT-LAMP assay displayed a detection limit of 1 × 10² copies/ml RNA close to that of RT-PCR; no cross-reactivity was observed in the 10 kinds of viruses studied. The results obtained with 638 clinical samples indicate that the developed method has high specificity (0.988-1) and sensitivity (0.863-1) for viruses studied, and the Kappa value of all viruses was more than 0.85 revealed an excellent agreement between the two methods. We developed an RT-LAMP-based method and optimized for the detection of common respiratory viruses. It may be a powerful tool for rapid and reliable clinical diagnosis of ADR in primary hospitals.