FbsA-dependent platelet aggregation byS agalactiaeandL lactisstrains. The ability of S agalactiae strains belonging to different serotypes and their corresponding mutants (ΔfbsA) to activate platelet aggregation in PRP was tested (A). The results are presented as percentage aggregation. In the panels the serotype of each strain is indicated. The aggregation tracings are representative of the data from 4 independent experiments performed in triplicate. Panel B shows platelet aggregation induced by the S agalactiae strains 6313 pOri23, 6313 ΔfbsA pOri23, and 6313 ΔfbsA pOrifbsA. Panel C shows platelet aggregation elicited by L lactis pOri23 and L lactis pOri23fbsA. The results are presented as percentage aggregation. The data were derived from 3 independent experiments performed in triplicate.