Visualization of intestinal infections with astro- and sapovirus in mink (Neovison vison) kits by in situ hybridization

Clarification of the infection microbiology remains a challenge in the pre-weaning diarrhea (PWD) syndrome in farmed mink (Neovison vison). Duodenal, jejunal and colon sections from 36 mink kits with PWD were systematically examined by chromogen in situ hybridization targeting two incriminated viruses: mink astrovirus and mink sapovirus. Using the RNAscope(®) 2.5 HD Duplex Assay, astrovirus and sapovirus were visualized and simultaneously demonstrated in the gut tissue. Both viruses infect enterocytes in the small intestine with a specific localization pattern; astrovirus affects the two apical thirds of the villi, whereas sapovirus generally affects the basal parts of the villi. Furthermore, we demonstrated that astrovirus in mink does not target the goblet cells. This is the first time astro- and calicivirus have been visualized in mink kit gut tissue, and these findings might be important in clarification of the impact of these viruses in the PWD syndrome.