Abstract: The present invention relates to a recombinant fusion protein and a polysaccharide conjugate vaccine. More specifically, the present invention relates to a fusion protein including a pentamer substrate protein and a peptide sequence capable of forming a trimer, an immunogenic composition including the fusion protein, the application of the fusion protein in immunology, a polynucleotide sequence encoding the fusion protein, an expression vector containing the polynucleotide sequence, and a host cell containing the expression vector.

Abstract: The present invention discloses a Acinetobacter baumannii immunogenic protein and its composition and application. This invention provides a protein, comprising 39 amino acids of the N-terminal ?-helix part of the Ata protein transport functional domain of Acinetobacter baumannii and an adjuvant protein; amino acid sequence of said 39 amino acids of the N-terminal ?-helix part of the Ata protein transport functional domain of Acinetobacter baumannii is shown as the 127th-165th amino acid residues of SEQ ID NO:2. In present invention the 39 amino acids of the N-terminal ?-helix part of surface protein Ata (Acinetobacter trimeric autotransporter) of Acinetobacter baumannii, was took to fuse with CTB, and express in BL21. The protein was purified by a nickel column, and used to intraperitoneally immunize mouses by 2.5 ?g/mouse. Its immunogenicity and immunoprotection was verified through the animal experiments, which proves it has a good effect of anti-infection of Acinetobacter baumannii.