A MONOCLONAL-ANTIBODY REACTIVE WITH A COMMON EPITOPE OF MORAXELLA (BRANHAMELLA) CATARRHALIS LIPOPOLYSACCHARIDES

A hybrid cell line producing a monoclonal antibody (MAb) against Morax ella (Branhamella) catarrhalis lipopolysaccharide (LPS) was establishe d. The specificity of the MAb 1B12 to purified rough LPSs from six str ains of M. catarrhalis was ascertained by enzyme-linked immunosorbent assay (ELISA), competitive-inhibition ELISA, and immunoblotting. MAb 1 B12 bound to live bacterial cells and culture supernatants from a tota l of 34 strains of M. catarrhalis, including 12 strains with different LPS serotypes. No cross-reactions with smooth and rough LPSs from sel ected enterobacterial and nonenterobacterial strains, with other respi ratory pathogens, or with Neisseria species were observed. These data suggest that MAb 1B12 recognizes a common epitope of M. catarrhalis LP S which differs from serotype determinants.