Proteins and polypeptides from coagulase-negative staphylococcal bacteria such as S. epidermidis, including proteins designated SdrF, SdrG and SdrH, and their effective fragments such as their respective A domains, are provided which are useful in the prevention and treatment of infection caused by coagulase-negative staphylococcal bacteria such as S. epidermidis. The SdrF, SdrG and SdrH proteins are cell-wall associated proteins that specifically bind host proteins and which each have a highly conserved motif of which the consensus sequence is TYTFTDYVD (SEQ ID NO: 16). The proteins and polypetides may be useful in generating antibodies for the diagnosis and treatment of coagulase-negative staphylococcal infections.