Bovine platelet aggregation by Fusobacterium necrophorum.

Fusobacterium necrophorum aggregated bovine platelets. The aggregation was paralleled by the haemagglutinating ability of the organism. Treatment of the bacterial cells with antiserum to the homologous purified haemagglutinin reduced the degree of platelet aggregation. Scanning electronmicroscopy revealed that little lysis of the affected platelets occurred during the 1-h incubation period. Purified haemagglutinin became bound to the surfaces of the platelet cells as shown by immunofluorescence microscopy. These observations suggest that platelet aggregation is mediated by the haemagglutinin and may be related to the pathogenicity of the bacterium.