Observations on the localization of Absidia corymbifera in vivo.

The role of spore distribution and the presence of tissue-specific fungal growth stimulants and inhibitors in determining the in vivo localization of Absidia corymbifera were examined in experimentally infected mice. Intravenous inoculation resulted in generalized distribution of spores, with the highest concentrations accumulating in the liver and spleen. Active lesions containing developing mycelium were confined to the brain, kidneys and occasionally the myocardium. Fungal growth stimulating activity was present in all tissue examined, the liver and spleen being the most active. However at concentrations approaching those of whole tissues, the stimulatory activity of liver and spleen extracts drastically declined whereas that of brain and kidney preparations continued to increase. These effects, in conjunction with local variations in immune processes, were probably responsible for determining the distribution of A. corymbifera mycelial development in vivo.