Agglutination of sheep erythrocytes by Corynebacterium diphtheriae.

The hemagglutinating activity of 26 strains of Corynebacterium diphtheriae isolated from the upper respiratory tract and from skin lesions was determined using both a macro and a micro-technique. Six of the 26 strains tested were unable to agglutinate sheep erythrocytes. Furthermore there was a considerable variation in the hemagglutinating activity of the positive strains.