Generation and characterization of monoclonal antibodies against Klebsiella pneumoniae

The present work was undertaken with the aim to generate highly specific monoclonal antibodies (MAb) targeted against Klebsiella pneumoniae that could be incorporated into a highly sensitive and simple ELISA (plate and dot) based system for the rapid identification of K. pneumoniae strains. Four murine monoclonal antibodies (KP-1, KP-2, KP-3, and KP-4) reactive to K. pneumoniae were generated and stabilized. Monoclonal antibodies KP-1 and KP-2 were of IgM type and KP-3 and KP-4 were of IgG type. All of the MAbs were found to be specific to K. pneumoniae strain, as they did not show any cross reactivity when tested with 22 different species and stains of members of the Enterobacteriaceae group. In Western blotting with whole cell lysate antigens of K. pneumoniae, KP-3 and KP-4 were found to react with 70 to 110 kDa regions. The nature of the epitope recognized by all four monoclonal antibodies was carbohydrate as determined by periodate and trypsin treatment of antigens. The monoclonal antibodies were further evaluated on 20 biochemical identified K. pneumoniae strains. The KP-3 and KP-4 monoclonal antibodies produced strong reactions with 19 and 18 strains, respectively, by dot-ELISA. KP-1 and KP-2 (IgM) did not show reaction in dot-ELISA but by agglutination test these could detect 11 and 13 strains, respectively.