Specificity of the antibodies raised against the recombinant proteins.

<p>The sera were used at final dilution of 1∶50, PpiC (square grid), PBP5 (horizontal stripes), LysM (vertical stripes) and DdcP (rhombic grid) and the strain tested was <i>E. faecium</i> E155. Purified recombinant proteins were used as inhibitors at concentration of 100 µg/mL, and were preincubated with the corresponding sera dilution for 1 h at 4°C prior to OPA. Opsonic killing of the target strain with non-absorbed antibodies was used to assess the reduction of opsonic killing produced by each inhibitor, using preimune rabbit serum (NRS, white bar) as a Control. Bars represent the mean of data and the error bars represent the standard error of the mean. Statistical significance was determined by ANOVA and Dunnett's Multiple Comparison Test. Comparing killing rates of similar dilutions (i.e. 1∶50) with the NRS, all comparisons were significant at p<0.001 (indicated by asterisk).