Rapid detection of Bordetella pertussis by a monoclonal antibody-based colony blot assay

Abstract

Monoclonal antibodies to Bordetella pertussis filamentous hemagglutinin (FHA) and lipopolysaccharide (LPS) were used in a colony blot enzyme-linked immunosorbent assay designed for rapid detection of B. pertussis. Bacterial colonies from Bordet-Gengou agar plates were blotted onto nitrocellulose filter disks, lysed by immersion in chloroform, and reacted with monoclonal antibodies. Following reaction with peroxidase-conjugated rabbit anti-mouse immunoglobulin antisera and 4-chloro-1-naphthol, blue dots representing single colonies appeared on the filters. Blotting of single B. pertussis colonies could be performed after incubation for 40 h, i.e., before the colonies were visible by eye on the agar surface. Ten of ten B. pertussis strains showed positive blotting reactions with antibodies specific for B. pertussis FHA and LPS. Fourteen B. parapetussis strains reacted with two of the FHA-specific antibodies but not with two of the LPS-specific antibodies. Strains of B. bronchiseptica showed a variable reaction pattern. No cross-reactions were observed with strains of Streptococcus mitis, S. pyogenes, S. pneumoniae, Staphylococcus aureus, Branhamella cararrhalis, or Klebsiella pneumoniae. This assay may be useful for identification of B. pertussis and B. parapertussis in suspected cases of whooping cough.