ADHERENCE OF BILOPHILA-WADSWORTHIA TO CULTURED HUMAN EMBRYONIC INTESTINAL-CELLS

Adherence of Bilophila wadsworthia to the cultured human embryonic int estinal cell Line, Intestine 407 (Int 407), varied among the strains t ested from strongly adherent (76-100% cells positive for one or more a dherent bacteria) to non-or weakly adherent (0-25% positive cells). Al though negative staining revealed that infrequent cells of an adherent strain, WAL 9077, the adherent type-strain, WAL 7959, and a non-adher ent strain, WAL 8448, expressed loosely associated fimbrial structures , a role for these structures in adhesion could not be confirmed with either scanning or thin-section electron micrography. Ruthenium red st aining of thin-section preparations and subsequent electron microscopy failed to reveal an extensive extracellular polysaccharide layer. SDS -PAGE analysis of crude outer membrane fractions of WAL 9077 and WAL 8 448 demonstrated clear differences in their major and minor outer memb rane protein components. Thus, we postulate that the adherence of B. w adsworthia to Int 407 cells is mediated by an outer membrane or cell w all component. (C) 1998 Academic Press.