Escherichia coli adhesion to Saccharomyces cerevisiae and mammalian cells: role of piliation and surface hydrophobicity

A number of Escherichia coli strains isolated from patients with urinary tract infections, bacteremia, or diarrhea were studied with respect to their (i) capacity to agglutinate human AB, bovine, and guinea pig erythrocytes as well as yeast (Saccharomyces cerevisiae) cells; (ii) adhesion to monolayers of cells from human intestine (intestine 407; ATCC CCL6), monkey kidney (Vero; ATCC CCL81), feline embryo (Flow no. 05-552), and porcine kidney (PK1; ATCC CRL1392) and of primary rat kidney cell cultures; and (iii) surface hydrophobicity as measured by hydrophobic interaction chromatography. No correlation could be found between the capacity of the bacteria to adhere to the different cultured mammalian cells and their agglutination patterns. The results indicated not only a complexity of bacterial receptors on the eucaryotic cells, but also a multiplicity of bacterial adhesions as expressed by the selectivity of bacterial binding. Binding of bacteria was found to be attributed to the presence of pili on the bacterial surface. It was observed that the bacteria were differently piliated: some had only common type I or related pili which gave rise to mannose-sensitive (MS) adhesion or agglutination (MS pili), some had only pili which gave rise to mannose-resistant (MR) adhesion or agglutination (MR pili), and some had both MS and MR pili. Bacteria with MS pili were more hydrophobic than those with MR pili or with none at all.