FIG 1.

(A) Adhesion of E. coli VR50 and 83972 (ABU strains) and CFT073 (UPEC strain) to HeLa human epithelial cells. Epithelial cells were inoculated with bacteria and incubated for 1 h, with adherent bacteria enumerated by direct plating and colony counts. The results are the averages of two independent experiments plus standard errors of the mean. E. coli VR50 adhered to the cells in equal numbers to the UPEC strain CFT073. (B) ELISA demonstrating levels of IL-6 secreted by HeLa epithelial cells infected with E. coli VR50 and CFT073. The results are the averages of four replicates plus standard errors of the mean. E. coli VR50 stimulated a significantly reduced IL-6 response compared to CFT073, despite a similar level of adherence (P < 0.001).