Abstract

Objective: Acinetobacter baumannii is an opportunistic pathogen that causes serious infections in humans by colonization of medical devices. The capacity of this pathogen to persist in hospital settings could be due to its ability to form biofilms. In the present study we evaluated the effect of antibodies against one of surface components of A. baumannii on in vitro biofilm formation. Materials and Methods: The 1113 bp fragment of Bap (biofilm associate protein)gene from A. baumannii genome was amplified and cloned. The recombinant protein was expressed and purified and used to raise antibodies in mice. Antibody titer was evaluated by ELISA. In vitro biofilm inhibition was evaluated using the mice sera. Results: Injection of Bap subunit resulted in high titers of antibody. Immunized mice serum had significant (P< 0.001) inhibitory effect on biofilm formation. In vitro inhibition of biofilm formation by A. baumannii was studied at 1:50 concentrations of immunized and unimmunized mice sera. Immunized mice serum had significant (P <0.001) inhibitory effect on biofilm formation Conclusion: Adsorption of antibodies to Bap might interfere with bacterial adhesion to the surface. These antibodies were found to be potent biofilm inhibitors.