Toxicity of Diplodia macrospora to laboratory animals

Abstract

The toxicity of Diplodia macrospora isolated from Zambian white maize to ducklings and rats is described. Pure cultures of D. macrospora on autoclaved maize were acutely toxic and caused the death of four out of four rats within 7 days and four out of four ducklings within 5 days. In a short-term toxicity trial dietary levels of 8, 16 and 32% mouldy meal in the diet caused the death of one, four and four male and nought, three and four female rats out of four in the respective treatment groups. Dietary levels as low as 2% mouldy meal caused significant reductions in weight gain of male and female rats compared to the controls. Pulmonary haemorrhage, alveolar, septal and perivascular oedema of the lung, mild cholangitis and a mild renal tubular nephrosis were the most important histological changes. Systemic shock, possibly related to a direct endothelial toxicity, appeared to be the main cause of death.