A novel Recombinase Polymerase Amplification Assay for rapid detection of epidemic Fowl Adenovirus

Zhang, Ji; Liu, Jie; An, Da; Fan, Yunhao; Cheng, Ziqiang; Tang, Yi; Diao, Youxiang

Fowl adenovirus (FAdV) has posed a grave threat to the health of poultry and the sudden outbreak highlights the importance of the new rapid diagnostic method for the control and prevention of transmission. Hence, in the present study, a novel recombinase polymerase amplification (RPA) assay, which was suitable for all 12 serotypes (FAdV-1 to 8a and 8b to 11) had been successfully launched to detect FAdV. Also, the entire amplification process could be completed in the isothermal condition when temperature ranged from 26 to 42 °C within no more than 14 min, which was remarkably superior to end-point polymerase chain reaction (PCR, 98 min) with the same detecting sensitivity (as low as 0.1 fg viral DNA), avoiding sophisticated thermal cyclers with simple operation. Additionally, the same primers did not produce positive reactions with other viruses tested, demonstrating that the specificity of the RPA assay was acceptable. Moreover, this developed method could be efficiently used in the diagnosis of FAdV references and epidemic strains from different avian origins, thus making it a rapid, reliable and point-of-care FAdV diagnostics tool, as well as an alternative to end-point PCR.