Establishment of a recombinase-aided amplification (RAA) assay for detection of Nocardia seriolae
YANG Huiyuan, CHEN Guoquan, WEN Yiming, XIA Hongli*, XIA Liqun*
1. Guangdong Provincial Key Laboratory of Aquatic Animal Disease Control and Healthy Culture, College of Fisheries, Guangdong Ocean University, Zhanjiang 524088, China; 2.Guangdong Provincial Engineering Research Center for Aquatic Animal Health Assessment, Shenzhen Public Service Platform for Evaluation of Marine Economic Animal Seedlings, Shenzhen Institute of Guangdong Ocean University, Shenzhen 518120, China
Abstract: To establish a recombinase-aided amplification (RAA) assay for the detection of Nocardiaseriolae, the primers for RAA were designed according to the specific genome fragments of N.seriolae with intraspecific conservation and interspecific variation. The specific primer of RAA was verified by detecting 7 related Nocardia spp. and 9 common pathogens in aquaculture, and the sensitivity of the detection method was analyzed by gradient dilution of the recombinant plasmid containing the target fragment. The reliability and coverage of the RAA assay were assessed in diseased and healthy fish as well as several N.seriolae strains from different sources. Results showed the RAA assay established in this study specifically detected N.seriolae, and the detection sensitivity was 100 pg/μL. The positive bands were amplified in the tissues including liver, kidney, and spleen of artificially infected hybrid snakehead (Channamaculate♀×C.argus♂), and the N.seriolae strains of different sources. The finding indicates that the RAA assay established in this study is rapid and convenient and can meet the needs for the rapid detection of N.seriolae.
2023, Vol. 38 
