Binding ability to immobilized human fibrinogen of the wild type (WT) L1 strain, and of isogenic mutant and complemented strains for <i>rgfAC</i>, <i>fbsA</i>, and <i>fbsB</i> genes.

<p>Flat bottomed 96-well polystyrene plates were coated with 21 nM human fibrinogen and 5×10⁶ to 5×10⁸ CFU per ml were added for 90 min at 37°C. Binding ability was calculated from the ratio between the number of bound bacteria and the number of bacteria present in the inoculum. Each experiment was performed at least three times. Boxes are means and bars are standard deviation of the means. The binding values of the mutant strains were significantly lower, at a <i>P</i> value of <0.001, than the values of the L1WT strain and of the corresponding complemented strains carrying <i>rgfAC</i>, <i>fbsA</i>, and <i>fbsB</i> genes on the pP1 plasmid.