Recombinase-Aided Amplification Combined with Lateral Flow Dipstick for the Rapid and Sensitive Detection of Trichomonas gallinae

Trichomonas gallinae is a protozoan parasite of the upper digestive tract of poultry and wild birds and poses a serious threat to the wild bird population and the pigeon industry globally. Therefore, rapid diagnosis and timely treatments are necessary to control T. gallinae. Although some conventional diagnostic methods have been described previously, these methods are hampered by omissions or high costs. In this study, the combination of biotin-labeled and FAM-labeled primers and probes for recombinase-aided amplification (RAA) with a lateral flow dipstick (LFD) was investigated to visualize the RAA results. The RAA-LFD assay was established for the on-site, rapid, and sensitive detection of T. gallinae. The RAA-LFD assay with Toxoplasma gondii, Neospora caninum, and Tetratrichomonas gallinarum did not produce a cross-reaction, which indicated that this RAA-LFD assay is specific for detecting T. gallinae. In addition, the RAA-LFD assay demonstrated high sensitivity with the lowest detection limit of 2.78 × 101 copies/μl of the Fe-HYD standard plasmid for T. gallinae. The complete detection process of the RAA-LFD assay was found to require 45 min. These results suggest that the RAA-LFD assay established in the present study may be promising for the rapid, specific, and sensitive detection of T. gallinae during surveillance efforts.