Molecular evidence for pap-G specific adhesion of Escherichia coli to human renal cells

Purpose: To study the interaction between class II G-adhesin of Escherichia coli and human urogenital cells. Material and Methods: The adherence of two wild type P-fimbriated E. coli strains, both carrying a class II G-adhesin, and two constructed mutants (one class II G-adhesin knock-out mutant and one class switch mutant in which the papG gene was exchanged with a prsJ96 allele which is a representative of the class III G-adhesin) to human urogenital cells were examined by light microscopy and flow cytometry. Results: The wild type E. coli strains adhered avidly to proximal tubular cells, but the isogenic mutant strains did only adhere in one of the experiments. A soluble receptor analogue inhibited bacterial attachment. Conclusions: These experiments strongly suggest that the papG class II tip adhesin of P-fimbriae is essential in the pathogenesis of human kidney infection.