Metabolic Alterations in Mucormycosis Infection §

Mucormycosis is a fungus infection which generally occurs in association with metabolic disorders, most frequently diabetes mellitus. The fungus has only recently been identified in culture when the phycomycetes Rhizopus oryzae and Rhizopus arrhizus were recovered from two diabetic patients with cerebral mucormycosis."'0 With these and other species of Mucorales, lesions closely resembling cerebral and pulmonary mucormycosis in man have been produced in rabbits with acute alloxan diabetes while non-diabetic animals showed only rare minute lesions at the site of inoculation.8" Clinical, postmortem and experimental findings indicate, therefore, that severe metabolic alterations are essential in the pathogenesis of this fungus infection."' To define the metabolic factors more accurately the following experiments were carried out. The effect of sustained hyperglycemia in rabbits without diabetes was studied since elevation of blood sugar is one of the principal metabolic abnormalities in diabetes. We had also noted previously that the fungus could be isolated in culture from non-diabetic rabbits without lesions as late as one week after inoculation. To test if experimentally induced metabolic alterations in a previously normal animal can change the fungus from a saprophyte to a pathogen, normal rabbits were inoculated with fungus at various times preceding the production of diabetes by alloxan administration.