FIG 7 .

CIII induces S. aureus biofilm formation in culture; in strain UAMS-1, this induction requires sarA. (A) For four S. aureus isolates, cell density (biofilm formation) was significantly greater in the presence of 50 µM CIII (gray bars; two-tailed, paired t test with Bonferroni correction: **, P < 0.05; *, P < 0.06) compared to DMF alone (black bars). E. coli MG1655 did not form biofilm under these assay conditions. Data are the means from five biological replicates; error bars represent SEM. (B) Representative photos taken of individual wells after 20 min of 1% crystal violet staining. (C) S. aureus UAMS-1 formed a biofilm in response to culture with SSD0Fe and 50 µM CIII (gray bars) but was unable to form a biofilm in identical conditions when the sarA gene was interrupted. Data represent the means from three biological replicates; error bars are SEM.