2.2. RNA extraction and cDNA synthesis
The fecal and ascetic fluid samples were fully resuspended in phosphate-buffered saline (1:5 w/v) and centrifuged at 10,000 × g for 10 min. According to the manufacturer’s instructions, viral RNA was extracted from 300 μL of the fecal suspension using RNAios Plus (TaKaRa Bio Inc). The cDNA was synthesized using the PrimeScript™ RT Reagent Kit according to the manufacturer’s instructions (TaKaRa Bio Inc) and then stored at –20 °C until required.