title: Identification of immunogenic proteins of the bacterium Acinetobacter baumannii using a proteomic approach.
abstract: OBJECTIVE
  Acinetobacter baumannii is an important opportunistic pathogen that causes pneumoniae, urinary tract infections, and/or septicemia in immunocompromised patients. This pathogen is frequently associated with nosocomial outbreaks worldwide and has become particularly problematic because of its prevalence and resistance patterns to several antibiotics. In the present study, we used an immunoproteome-based approach to identify immunogenic proteins located on the surface of A. baumannii for the development of a possible immunotherapy against this devastating bacterial infection.
  
  
  METHODS
  Sera from patients with A. baumannii infections (n = 50) and from a control group of healthy individuals (n = 3) were analyzed for reactivity against A. baumannii outer membrane proteins (OMPs) using Western blot analysis. To identify potential immunogenic proteins in A. baumannii, OMPs were separated by 2DE, and reactive sera from infected patients were randomly selected and divided into two different pools, each containing 15 sera. Finally, MALDI-TOF/TOF mass spectrometric analysis was employed to identify the corresponding proteins.
  
  
  RESULTS
  This analysis identified six immunoreactive proteins: OmpA, Omp34kDa, OprC, OprB-like, OXA-23, and ferric siderophore receptor protein. Notably, these proteins are highly abundant on the bacterial surface and involved in virulence, antibiotic resistance, and growth.
  
  
  CONCLUSIONS
  Our results support the notion that the proteins identified in the present immunoproteome study could serve as antigen candidates for the development of vaccines and passive immunotherapies against A. baumannii infections.
authors.affiliation: Instituto de Tecnologia em Imunobiológicos, Fiocruz, Rio de Janeiro, Brazil.
authors.forename: Renata
authors.initials: R
authors.lastname: Fajardo Bonin
authors.forename: Alex
authors.initials: A
authors.lastname: Chapeaurouge
authors.forename: Jonas
authors.initials: J
authors.lastname: Perales
authors.forename: José Godinho
authors.initials: JG
authors.lastname: da Silva
authors.forename: Hilton Jorge
authors.initials: HJ
authors.lastname: do Nascimento
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: D'Alincourt Carvalho Assef
authors.forename: José Procópio
authors.initials: JP
authors.lastname: Moreno Senna
mesh_terms: D000151:Acinetobacter Infections / Q000097:blood / Q000276:immunology* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000276:immunology* / Q000502:physiology; D001425:Bacterial Outer Membrane Proteins / Q000097:blood / Q000276:immunology; D001426:Bacterial Proteins / Q000097:blood / Q000276:immunology*; D015153:Blotting, Western; D015180:Electrophoresis, Gel, Two-Dimensional; D054884:Host-Pathogen Interactions / Q000276:immunology; D006801:Humans; D020543:Proteome / Q000276:immunology*; D040901:Proteomics / Q000379:methods*; D011956:Receptors, Cell Surface / Q000097:blood / Q000276:immunology; D015203:Reproducibility of Results; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D020543:Proteome; D011956:Receptors, Cell Surface; C035902:siderophore receptors; C078167:OMPA outer membrane proteins
keywords: Acinetobacter baumannii; Hospital infection; Immunoproteomics; MALDI-TOF/TOF