Experimental aspergillosis in rats infected via intraperitoneal and subcutaneous routes.

Normal adult rats infected via the subcutaneous (s.c.) route with viable spores of Aspergillus fumigatus develop serum antibodies, measured by passive haemagglutination and passive cutaneous anaphylaxis (PCA), to extracts of the fungus. No significant histological abnormality was detected but s.c. inoculation in cortisone-treated animals induced the formation of granulomas frequently found in lymph nodes including those of the mesentery and paratracheal group. These granulomas were associated with the presence of both spores and fungal hyphae. Intraperitoneal inoculation of A. fumigatus spores occasionally produced lesions containing hyphae in the liver, spleen and mesenteric lymph nodes. Lesions were more frequent and extensive in cortisone-treated rats where again they were most prominent in the mesenteric lymph nodes. None of the regimes produced fatal hyphal aspergillosis. Both normal and cortisone-treated rats developed serum agglutinins but not reagins following intraperitoneal injection of spores.