Abstract

Sodium dodecyl sulphate polyacrylamide gel electrophoresis and immunoblotting were used to characterise isolates of Haemophilus ducreyi. Isolates of H ducreyi were heterogeneous in protein composition, but isolates from single outbreaks appeared similar both in protein profiles and antigenic analysis. Rabbits immunised with H ducreyi responded with a vigorous humoral immune response in which multiple antigenic polypeptides were detected. The most prominent antigens had molecular masses of 67, 42, 22.5, and 20 kilodaltons.