FIG 1 .
Biofilm biomass is reduced in vitro by the presence of AliC and AliD. (A) Biofilm formation was quantified at 24 h after seeding a 24-well plate with 105 pneumococci and corresponds to wild-type strains MNZ85 and MNZ41 set to 100% formation. The strain backgrounds are indicated by the color key. (B) Pneumococcal viability in the biofilm was assessed at 24 h by collecting biofilms and plating on BA to enumerate CFU. In panels A and B, values are means plus standard errors of the means (error bars) from at least two independent studies performed in triplicate. Values that are significantly different are indicated by asterisks as follows: *, P < 0.05; **, P < 0.01. (C) Micrographs of 24-h biofilms stained with crystal violet and captured at ×10 magnification. Deletion of aliC and aliD significantly increased biofilm formation in both strain backgrounds (A and C) but did not affect NESp viability in biofilms (B).