Protective Activity of Anti-Exotoxin A Monoclonal Antibody against Mice Infected with Toxin-Producing Pseudomonas aeruginosa

Abstract

The neutralizing and protective effect of murine monoclonal antibody (MAb) 3C7 (IgG1) against Pseudomonas aeruginosa exotoxin A was examined in an experimental mouse model of infection with exotoxin A-producing strains. Treatment with MAb 3C7 blocked the reduction of functional elongation factor 2 (EF-2) in the liver of mice but could not clear the bacteria. Administration of gentamicin caused bacteria to be cleared but did not block reduction of hepatic EF-2 level. Treatment with either MAb 3C7 or gentamicin individually did not prolong time to death; however, the combined therapy with both MAb 3C7 and gentamicin cleared bacteria and blocked the reduction of hepatic EF-2 level, resulting in a significant increase in the survival rate of mice. These results suggest that anti-exotoxin A MAbs show effectiveness against pseudomonal infection caused by exotoxin A-producing strains.