Effect of experimentally-induced villus atrophy on adhesion of K88ac-positive Escherichia coli in just-weaned piglets

Three- to four-week-old, just-weaned piglets were infected with transmissible gastroenteritis (TGE) virus and the next day with K88ac(+) enterotoxigenic Escherichia coli (ETEC). Histological examination of caudal jejunum and ileum of piglets killed 2–3 days after virus challenge (1–2 days after ETEC infection) revealed severe villus atrophy especially in the jejunum compared with controls (P<0.05). Four-5 days after TGE virus infection villus length increased and after 7 days it was near normal. Villi scraped from jejunal and ileal mucosa of the piglets were incubated in vitro with K88ac(+)E. coli and the number of bacteria adhering to 250 μm villus brush border was counted. Attachment of bacteria to villi of piglets killed 2–3 days after TGE virus infection was significantly decreased in comparison with adhesion to villi of non-infected piglets or of piglets killed 7 days after the virus infection. Correlation between in vitro adhesion and villus height was 0.6649 (P<0.001). The results suggest that the experimentally-induced villus atrophy was attended with a temporarily diminished susceptibility of villus enterocytes to adhesion of K88ac(+)E. coli.