In vivo attachment of E coli to human epithelial cells

There was a high incidence of a mannose sensitive adhesin and a mannose resistant and eluting adhesin among 111 Escherichia coli urinary isolates and 23 faecal isolates. Attachment of E coli to human uroepithelial and buccal cells was significantly higher for strains possessing a mannose resistant adhesin after growth on agar. Strains possessing a mannose sensitive adhesin after single or multiple subculutres in broth did not attach in large numbers and the adherence was unaffected by the presence of D-mannose. The mannose resistant adhesin was more often detected in strains with O serotypes commonly found in urinary tract infections, was produced at 37C but not at 18C and was destroyed or weakened by exposure to heat and formaldehyde treatment. Electron microscopy confirmed fimbrial presence on 67% of strains producing a mannose resistant adhesin, but non-fimbriated strains attached equally well to uroepithelial cells.