Adhesion properties of E. coli cells in the presence of promethazine.

Some E. coli strains were tested for adsorption to HEp-2 cells and on aluminium hydroxide gel. The adhesiveness of E. coli to HEp-2 cells was inhibited by promethazine. MRHA (mannose-resistant haemagglutinating activity) positive plasmid-carrying E. coli strains were found to be adsorbed to tissue culture cells more effectively than the MRHA-negative strains. Fifty percent of the clinical isolates contained antibiotic resistance plasmids, but only 40% of these strains were able to transfer the antibiotic resistance properties to E. coli as recipient. It is presumed that the hydrophobic adsorption of bacteria depends on the fimbriae, while aluminium hydroxide gel adsorption correlates with surface properties other than the fimbriae.