Mouse infection schemata for Swiss Webster mice. Swiss Webster mice were infected orally in two separate experiments to determine effects on intestinal tissue-associated microbial communities. (A) Mice were infected orally with two murine norovirus (MNV) strains, MNV-1 and MNV-4, and compared to a mock-infected control. At days 1 and 3 following infection intestinal tissues were harvested. (B) Mice were infected orally with MNV-1 or mock lysate and tissues harvested on days 7, 28, and 56 post infection. DPI = days post infection; pfu = plaque forming units.