Loop-Mediated Isothermal Amplification Combined With Lateral-Flow Dipstick for Detection of Centrocestus formosanus in Ornamental Fish

Abstract

The minute intestinal trematode Centrocestus formosanus is a major problem that can be found in the gills of various fish species. This parasite can destroy the gill structure of fish, leading to increased fish morbidity and mortality rates. In this study, loop-mediated isothermal amplification (LAMP) based on the internal transcript spacer 1 region combined with a lateral-flow dipstick (LAMP-LFD) assay was used to detect C. formosanus in goldfish, Carassius auratus. The results showed that LAMP-LFD was specific to C. formosanus and had no cross-amplification with other co-infecting parasite species, close related parasite species or their hosts (both intermediate host and definitive host). The limit of detection is as low as one metacercaria per gill. In testing 40 goldfish gill samples, the LAMP-LFD method showed 100% accuracy when compared to traditional morphological identification. This method can be used as a rapid diagnostic tool for C. formosanus detection to obtain epidemiological information for monitoring, controlling, and preventing outbreaks of this parasite.