Figure 1From: Diversity and biofilm-production ability among isolates of Escherichia coli phylogroup D belonging to ST69, ST393 and ST405 clonal groupsQuantitative biofilm-producing assay. The vertical axis represents the median optical density (OD) of at least 15 replicas of each isolate, determined at 570 nm. E. coli CFT073 was used as a positive control. Horizontal dotted lines represent the cut-off value between weakly adherent (light gray) and moderately adherent (gray) (1) and strongly adherent strains (dark grey) (2).Back to article page