Data sets.

<div> The Gram-positive pathogens of the ESKAPE group, <i>Enterococcus faecium,</i> and <i>Staphylococcus aureus</i>, are well-known to pose a serious risk to human health because of their high virulence and numerous drug resistances. To narrow down the list of previously identified promising protein vaccine candidates, a combination of several antigen discovery approaches was performed, in particular a “false positive analysis” of peptides generated by trypsin shaving with a subtractive proteome analysis. The final list of nine potential antigens included AdcA_au, a protein performing the same function as AdcA_fm, an already discovered antigen in enterococci. Bioinformatic analyses revealed that AdcA_au and AdcA_fm share a sequence identity of 41.2% and that the conserved regions present a high antigenicity. AdcA_au was selected for further investigation and the results reported in this manuscript demonstrate the opsonic properties of AdcA_au-specific antibodies against the <i>Staphylococcus aureus</i> strain MW2, as well as their cross-binding and cross-opsonic activity against several <i>S. aureus, E. faecium</i>, and <i>E. faecalis</i> strains. The experimental design revealed several promising vaccine candidates, including the newly identified <i>S. aureus</i> antigen, AdcA_au. The study shows its potential as a vaccine candidate to prevent infections by dangerous Gram-positive ESKAPE pathogens. </div>