Provided is the use of a composition in the preparation of a medicament for treating an infection in a subject caused by a Staphylococcus spp., or for treating a subject at risk of having an infection caused by a Staphylococcus spp., wherein the composition comprises: at least three isolated polypeptides having molecular weights of 88 kDa, 55 kDa, 38 kDa, 37 kDa, 36 kDa, 35 kDa, 33 kDa, or a combination thereof, wherein molecular weight is determined by electrophoresis on a sodium dodecyl sulphate polyacrylamide gel, wherein the polypeptides are isolatable from a Staphylococcus aureus when incubated in media comprising an iron chelator and not isolatable when grown in the media without the iron chelator, and wherein the composition protects an animal against challenge with S. aureus ATCC strain 19636.
