An investigation of the factors involved in increased adherence of C. albicans to epithelial cells mediated by E. coli.

An in vitro study was carried out in order to investigate the effect of Escherichia coli on the adherence of Candida albicans to epithelial cells. Pre-incubation of HeLa cell monolayers with E. coli cell suspensions resulted in a large, significant increase in candidal adherence. Similar increases in adherence to HeLa cells were observed when incubation of C. albicans and HeLa cell monolayers was carried out in the presence of a mannose-specific lectin, concanavalin A. The enhanced adhesion of C. albicans due to both E. coli and concanavalin A was significantly reduced in the presence of mannose and alpha-methyl-D-mannoside although both sugars alone significantly increased candidal adherence. These studies indicate that the increased candidal adherence due to the presence of E. coli is mediated by the presence of fimbriae on the bacterial cells and mannose-like receptors on both the surfaces of C. albicans and the epithelial cells.