ObjectiveTo explore the related protein mediating Acinetobacter baumannii (AB) bloodstream infection(BSI), provide a new research direction for AB bloodstream infection(BSI).MethodsAB strains with the identical multilocus sequence typing (MLST) but isolated from different sites were retrieved from AB gene database, related differential protein which only existed in AB of BSI were analyzed by bioinformatics, and functional annotation analysis was conducted.ResultsUnder the established retrieval conditions, a total of 10 strains of AB were retrieved and divided into three groups according to MLST, including 4 strains of ST92 (2 strains from blood, and 2 from sputum), 4 strains of ST137 (2 from blood, and 2 from sputum), and 2 strains of ST365 (1 from blood, and 1 from sputum). Gene and protein database analysis results showed that partial protein only existed in AB of BSI, didn’t exist in AB isolated from sputum, there were 20, 4, and 22 specific protein in AB causing ST92, ST137, and ST365 BSI, respectively. The biological process in which specific protein involved was mainly concentrated on bacterial virulence and invasiveness, bacterial metabolism, DNA synthesis, DNA damage and repair, transcription, translation, gene translocation, and phagerelated protein.ConclusionBecause of individual difference, AB of the same MLST expressing the above differential protein may be the cause of BSI.