Toxicity to experimental animals of 943 isolates of fungi.

Nine hundred and forty-three isolates of fungi, in 40 genera, from feeds and from peanut fruits and seeds, were grown in autoclaved moist corn or corn-rice mixture, and fed to experimental animals, mainly rats. Of 527 isolates from feeds, 284, or 54% resulted in death of the animals to which they were fed in 7 days or less. Of 416 isolates from peanuts, 155, or 37%, resulted in death of the test animals to which they were fed in 7 days or less. Four genera —AlternarÃ-a, Aspergillus, Fusarium, and Pénicillium—made up 628 of the total of 943 isolates, or 67%, and included 336 or 77% of the total of 439 isolates lethal in less than 7 days to the animals to which they were fed. Of the 60 isolates of Alternada from feeds, 53, or 90% were lethal to rats. A high percentage of isolates of Chaetomium, Cladasporium, and Trichothecium from feeds, and of Sclerotium, from peanuts, were lethal in 7 days or less to the rats to which they were fed. Antemortem signs included leucopenia, increased prothrombin time, hemoglobulinuria, bilateral squint, and central nervous system disturbances. Lesions most commonly encountered at necropsy were hemorrhaging into the gastrointestinal tract and hemoglobinuria. Bone marrow studies showed either hypoplasia of all cellular elements or a severe maturation arrest of the myeloid cell series.