pH-dependent adhesion of piliated Corynebacterium renale to bovine bladder epithelial cells

The adhesion of Corynebacterium renale 115 to bovine bladder epithelial cells was studied with two clones of the bacteria, piliated (P+) and nonpiliated (P-). The percentage of the cells with attached P+ bacteria was greater than that of the cells with attached P- bacteria, and the number of attached P+ bacteria was higher than that of the P- bacteria. The adhesion of P+ bacteria was found to be pH dependent, which was supported by the following facts: the number of attached bacteria was high at a pH above 7.6 and low at a pH below 6.8; the adhering P+ bacteria were eluted immediately after the pH was decreased from 7.4 to 6.4; and the P+ bacteria unattached at pH 6.4 adhered to the cells immediately after the pH was increased to pH 7.4. The adhesion of P+ bacteria was inhibited by anti-pilus antiserum. The adhesion was not inhibited by amino acids or sugars, including mannose, and was not influenced by Ca2+ and Mg2+. P- bacteria hardly attached to the epithelial cells, irrespective of the pH and other factors.