The present invention relates to an isolated polypeptide antigen of Acinetobacter baumannii, comprising at least an amino acid sequence selected from the group consisting of: (a) SEQ ID NOs: 1-5 (b) an amino acid sequence having at least 80% sequence identity to SEQ ID NOs: 1, 3, 4 or 5 (c) an amino acid sequence having at least 60% sequence identity to SEQ ID NO: 2 and (d) a fragment of the amino acid sequence according to (a) to (c) wherein the polypeptide having the amino acid sequence according to (b) to (d) has immunostimulatory activity. The universal polypeptide antigens of Acinetobacter baumannii can be used in the universal vaccine preparation. The corresponding antibodies can be used in the diagnostic and treatment of Acinetobacter baumannii.
