A multiplex recombinase polymerase amplification assay combined with CRISPR/Cas12a for the detection of respiratory syncytial virus and respiratory adenovirus

ObjectiveRespiratory syncytial virus (RSV) and respiratory adenovirus (ADV) are two common pathogens that cause acute respiratory tract infections in children. We aimed to develop a rapid method for detecting both pathogens simultaneously.MethodsThe recombinase polymerase isothermal amplification (RPA) method was combined with the CRISPR/Cas detection system. The assay's specificity and sensitivity were explored by designing RPA primers and CRISPR RNAs (crRNAs) through multi-sequence comparisons, optimizing the reaction conditions, and using a fluorescent reading device. The consistency of the test results of 160 clinical pharyngeal swab samples was studied using quantitative polymerase chain reaction (qPCR) results as a comparative control.ResultsRSV and ADV could be detected at levels as low as 104 copies/mL and 103 copies/mL, respectively, within 50 minutes with no cross-reactivity with other similar pathogens. For the clinical samples, compared with the qPCR method, the sensitivities for RSV and ADV were 98.1% and 91.4%, respectively, and the detection specificities were both 100%. The Kappa values were greater than 0.95, suggesting a high degree of consistency.ConclusionThis method for detecting RSV and ADV is rapid, sensitive, and specific. It can accurately detect mixed infections in a timely manner, making it suitable for use in areas with scarce healthcare resources.