The production and characterisation of rabbit antiserum and murine monoclonal antibodies to Haemophilus ducreyi

Department of Medical Microbiology, Wright-Fleming Institute, St Mary's Hospital Medical School, Praed Street, London W2 1PG * Correspondence should be sent to Dr Q. N. Karim. Received July 27, 1989 Revision received October 9, 1989. Rabbit antiserum and murine monoclonal antibodies were raised against a strain of Haemophilus ducreyi . The antiserum gave high immunofluorescence titres and strong dot blot reactions with all H. ducreyi strains tested and the only cross reaction was with Bordetella pertussis . Three monoclonal antibodies, all of isotype IgG2a, also gave high immunofluorescence titres with H. ducreyi but did not cross react with any other species tested. Immunoblotting showed the monoclonal antibodies to react with a single polypeptide band of mol. wt 29 000 in the outer-membrane fraction of H. ducreyi . These antibodies have potential for use as diagnostic reagents and for investigating the pathogenicity of H. ducreyi .