Protection against Acinetobacter baumannii infection via its functional deprivation of biofilm associated protein (Bap)

Microb Pathog. 2011 Dec;51(6):402-6. doi: 10.1016/j.micpath.2011.09.004. Epub 2011 Sep 22.

Abstract

Acinetobacter baumannii, a major nosocomial pathogen, has remarkable capacity to acquire antimicrobial resistance attributable to its biofilm formation ability. Biofilm associated protein (Bap), a specific cell surface protein, is directly involved in biofilm formation by A. baumannii and plays a major role in bacterial infectious processes. In the present study we cloned, expressed and purified a 371 amino acid subunit of Bap. Mice were immunized using recombinant Bap subunit. They were then challenged with A. baumannii to evaluate the immunogenicity and protectivity of Bap subunit. Humoral immune response to Bap was determined by ELISA. Injection of Bap subunit resulted in high antibody titers. Decrease in bacterial cell counts of the immunized mice was evident 18 h after challenge. Reaction of antibodies against Bap with several strains suggests that not only immunodominant regions of Bap in A. baumannii strains are conserved but also have the same epitope presenting pattern in different strains. Immunodominant region of Bap possesses target sites for a protective humoral immune response to A. baumannii. This seems to be a conserved region erecting efficacy of Bap as an appropriate vaccine candidate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acinetobacter Infections / immunology
  • Acinetobacter Infections / prevention & control*
  • Acinetobacter baumannii / pathogenicity*
  • Animals
  • Antibodies, Bacterial / blood
  • Bacteremia / immunology
  • Bacteremia / prevention & control
  • Bacterial Load
  • Bacterial Proteins / antagonists & inhibitors*
  • Bacterial Proteins / immunology
  • Bacterial Vaccines / administration & dosage
  • Bacterial Vaccines / immunology
  • Biofilms / growth & development*
  • Cross Protection
  • Enzyme-Linked Immunosorbent Assay
  • Mice
  • Mice, Inbred BALB C
  • Vaccines, Subunit / administration & dosage
  • Vaccines, Subunit / immunology
  • Virulence Factors / antagonists & inhibitors*
  • Virulence Factors / immunology

Substances

  • Antibodies, Bacterial
  • Bacterial Proteins
  • Bacterial Vaccines
  • Vaccines, Subunit
  • Virulence Factors