Toxicity of a moniliformin-producing strain of fusarium moniliforme var. subglutinans isolated from maize

Pure cultures of a very toxic strain of Fusarium moniliforme Sheldon var. subglutinans Wr. & Reink., isolated from maize (Zea mays L.) and cultured on autoclaved maize, were fed to ducklings and rats. Ducklings consuming 0·5-2·0 g of mouldy meal died within 2 hr and those given doses of material derived from a methanol extraction of chloroform-extracted meal died in less than 60 min. The culture material was also acutely toxic to rats, males being more sensitive than females to the toxic effects of low dietary levels of mouldy meal. Semi-quantitative analysis based on UV spectrophotometry of methanol extracts of this mouldy meal revealed very high levels of moniliformin (up to 11·3 g/kg) in the toxic mouldy meal, and bioassay in ducklings demonstrated a dose-effect relationship for batches of culture material containing different levels of the toxin. The oral LD50 of chemically pure moniliformin was 3·68 mg/kg in 7-day-old ducklings and 50·0 and 41·57 mg/kg, respectively, in male and female inbred BD IX black rats (c.100 g), with both species showing progressive muscular weakness, respiratory distress, cyanosis, coma and death. Autopsy of the rats showed acute congestive heart failure and the histological lesions, although non-specific, were characterized particularly by acute focal myocardial degeneration and necrosis, while severe cloudy swelling and scattered single-cell necrosis occurred in the liver, kidney, pancreas, adrenal glands, gastric mucosal glands and crypts of the small intestine. The myocardium was also the site of the major lesions in rats fed. F. moniliforme var. subglutinans culture material. Acute hydropic degeneration, focal Zenker's necrosis, myolysis and fibrosis occurred in all the experimental groups to an extent varying with the duration of intake and the dietary level of the mouldy feed. Rats on a diet containing 8% culture material showed the most extensive lesions. Less severe myocardial lesions occurred in rats fed a diet containing 2% culture material. © 1977.