Extraction and Purification of Viral dsRNA

The total viral nucleic acid material was extracted as described previously [26 (link)]. Briefly, approximately 100 mg of stool sample was added to 200 µL of phosphate-buffered solution (PBS) (Sigma-Aldrich^®, Saint Louis, MO, USA) to create a stool suspension. A total of 300 µL of the stool suspension was added to 900 µL of TRI Reagent^® (Sigma-Aldrich^®, Saint Louis, MO, USA) after the stool suspension stood for 10 min at room temperature. Thereafter, the mixture was centrifuged (Eppendorf centrifuge 5427R, Hamburg, Germany) at 18,000 RPM for 20 min at 4 °C. A volume of 700 µL of ice-cold isopropanol (Sigma-Aldrich^®, Saint Louis, MO, USA) was added, and the mixture was left to dry for 10 min to precipitate the supernatants. The extracted nucleic material was incubated in 8M LiCl2 (Sigma-Aldrich^®, St Louis, MO, USA) at 4 °C for 16 h to enrich the dsRNA viruses and remove impurities. The extracted nucleic acid material was thereafter purified using a MinElute gel extraction kit (Qiagen, Hilden, Germany), and the integrity and enrichment of the dsRNA were verified via 1% agarose gel electrophoresis and visualized using an ultraviolet (UV) transilluminator (Sigma-Aldrich^®, Saint Louis, MO, USA).