Humoral response to experimental petriellidiosis.

The humoral antibody response elicited by experimental infection with Petriellidium boydii and Monosporium apiospermum was studied. The variables of fungus strain, route of inoculation, and concentration of inoculum were examined. Viable spores from three strains of P. boydii and from three strains of M. apiospermum were inoculated intravenously into mice. Serum specimens were tested for antibody by the microtiter indirect hemagglutination assay. At 4 weeks after infection, the percentage of positive specimens among survivortically related either to the incidence of positive specimens or to the magnitude of the humoral response. Mice inoculated by either the subcutaneous or the intramuscular route with viable or killed spores from M. apiospermum 813 developed antibody. The mean antibody titer was greater in those animals receiving viable spores, and the magnitude of the humoral response was dose dependent. Animals inoculated intravenously with comparable inocula of the same strain developed similar levels of antibody. However, cultural studies of infected mice showed chronic infection only after intravenous inoculation. The kidney was the organ most consistently involved.