Human cultured intestinal cells express attachment sites for uropathogenicEscherichia colibearing adhesins of the Dr adhesin family

We have recently demonstrated that cultured human intestinal HT-29 and Caco-2 cell lines express receptors for the F1845 fimbrial adhesin harbored by the diarrheagenic C1845 Escherichia coli (Kernéis et al., Infect. Immun. 59 (1991) 4013-4018). This adhesin belongs to a family of adhesins including the Dr hemagglutinin and the afimbrial adhesin AFA-I harbored by uropathogenic E. coli. Here we investigated the cell association of laboratory E. coli strains expressing the Dr hemagglutinin and the afimbrial adhesin AFA-I with human cultured enterocyte-like or mucosecreting cells. We observed that the E. coli strains bearing these adhesins adhere both to human intestinal undifferentiated and differentiated fluid-transporting cells, and to mucus-secreting cells. This result strongly suggests a high capacity of intestinal colonization for the uropathogenic E. coli harboring adhesive factors belonging to the Dr adhesin family. These results further corroborate the intestinal colonization by uropathogenic E. coli of the Dr family related to the fecal-perineal-urethral hypothesis of urinary tract infection pathogenesis.