The most common disease caused by Corynebacterium diphtheriae is diphtheria, an acute communicable disease manifested by both local infection of the upper respiratory tract and the systemic effects of the toxin, which are most notable in the heart and peripheral nerves. Hoyle Medium Base, formulated by Hoyle, is the modification of the original formulation of Neill, for the isolation and differentiation of C. diphtheriae. This medium is not inhibitory to some mitis types of Corynebacterium, as the original formulation.

for differentiation and isolation of Corynebacterium diffhtheriae