ENVIRONMENTAL ALTERATION AND 2 DISTINCT MECHANISMS OF ESCHERICHIA-COLI ADHERENCE TO BLADDER EPITHELIAL-CELLS

Abstract

An in vitro model was used to investigate E. coli attachment to transitional epithelial cells obtained from bladders of female rats. Adhesive abilities and sensitivity to mannose inhibition differed among the isolates for epithelial cells and erythrocytes. Adherence of some strains could be modulated by bacterial washes and growth media. Variations in adhesiveness were related to bacterial piliation as determined by transmission EM. With 2 strains, mannose inhibition of adherence to epithelial cells was dose-related; with a maximal inhibitory dose, adherence was reduced by .apprx. 80% even when the bacteria-to-epithelial cell ratio was varied. Evidently, adhesiveness and piliation of certain adhesive E. coli strains are reduced or enhanced by environmental alterations. Apparently, E. coli strains adhere to epithelial cells by at least 2 distinct mechanisms and a single isolate may use both mechanisms. The more efficient process is pili-mediated and inhibited by mannose; undetermined surface components mediate the less efficient but mannose-resistant mechanism.