Cortisone and Local Injury in Mucormycosis ‡§

The fungus Rhizopus oryzae which belong to the order Mucorales is a unique test agent to study the effects of metabolic alterations on infection since it behaves differently in the metabolically normal and abnormal host. This fungus was originally isolated at autopsy from a diabetic patient who died with cerebral mucormycosis.' We have shown in previously reported experiments that inoculation of the fungus in rabbits with acute alloxan diabetes produces extensive nasal, pulmonary, and cerebral lesions which closely resemble those of mucormycosis in man.' Inoculation of the fungus into normal rabbits produces only rare and minute circumscribed lesions at the site of inoculation. Similar experimental results have been obtained by other investigators who employed another fungus of the order Mucorales, Rhizopus arrhizus.' We have found further that hyperglycemia induced by continuous intravenous infusion and not associated with diabetes mellitus produces in rabbits nasal and sometimes pulmonary lesions which, although more numerous and extensive than the lesions in normal animals, do not approach the extent and severity of the lesions in rabbits with acute alloxan diabetes.' The fungus lesions in both diabetic and hyperglycemic nondiabetic rabbits have in common striking degenerative changes in the polymorphonuclear leukocytes consisting of nuclear pyknosis and karyorrhexis. The following experiments attempt to define further the metabolic alterations which are essential in the pathogenesis of mucormycosis. Because of the known decrease of host resistance to infection following cortisone administration the effect of this hormone on experimental mucormycosis in rabbits was studied in one series of experiments. In other experiments, the