Adherence of to gut epithelium and the tegument mediated L-fucose binding adhesin.

Recent reports implicate both the liver fluke as a reservoir of within the human gastrointestinal tract and in the pathogenesis of opisthorchiasis-associated cholangiocarcinoma. We postulated that adherence of bacterial ligands to host receptors initiates colonization of the live fluke by and here we aimed to assess the molecular interaction between . and . by investigating host receptors for in the fluke. Several known receptors of including Lewis B, sialyl-Lewis X, Toll-like receptor 4 and L-fucose were detected immunohistochemically and histochemically by focusing analysis on the gut epithelium and tegument of the adult stage of the fluke. The frequency of detection of Lewis B, sialyl-Lewis X, TLR4 and L-fucose in 100 individual worms was 3, 3, 19 and 70%, respectively. Detection of by a diagnostic gene-based PCR assay revealed the presence of in individual worms in 41 of 49 (79%) worms examined. In addition, numbers of bacteria decreased in a dose- and time-dependent fashion following exposure to fucosidase. These findings suggested that L-fucose represents a tractable receptor for that can mediate bacterial colonization of the gut of .