The effect of pure Fusarium toxins (T-2, F-2, DAS) on the microflora of the gut and on plasma glucocorticoid levels in rat and swine.

The gut microflora and adrenal cortex hormone levels were monitored in HUNGAHYB piglets of 10-12 kg and in Wistar rats of 100-150 g body weight fed with different pure Fusarium toxins. The feeding of either T-2, T-2 + F-2 and DAS toxins at the 5 microgram/g feed level for one week resulted in the substantial increase of aerobic bacteria count of the intestine. Increase of the DAS dose to a twofold level failed to elicit dose-response and no further increases in bacterial counts were observed. Following the uptake of toxin containing feed, the plasma cortisol and corticosterone levels showed a 2-3 fold rise. Intramuscular administration of toxin T-2 also increased the activity of the adrenal cortex and gut microflora counts also increased. It is suggested that the observed changes in the gut microflora may contribute to the appearance of clinical symptoms developing after feeding of toxins as well as to the triggering and maintaining of the stress.

Identification of mycotoxins produced by species of Fusarium and Stachybotrys obtained from Eastern Europe.

Isolates of Fusarium and Stachybotrys spp. and crude extracts from these fungi were obtained from Hungary and the U.S.S.R. and used for the evaluation of the mycotoxins they produced. The cultures were grown on millet and oats and extracted in Budapest, Hungary (Veterinary Medical Research Institute) and chemically analyzed at the University of Minnesota using thin-layer chromatography (TLC), gas-liquid chromatography (GLC), gas chromatograph-mass spectrometry (GC-MS), and the rat skin bioassay. Zearalenone was found in most of the Fusarium cultures, T-2 toxin, neosolaniol, T-2 tetraol, and HT-2 toxin were found in extracts of Fusarium poae and F. sporotrichioies. A special effort was made to isolate the steroid-like toxins reported in the early Russian literature as sporofusarin and poaefusarin. None of the extracts from the Fusarium species yielded poaefusarin or sporofusarin when analyzed by our chemical methods or by those of L.E. Olifson, S.M. Kenina, and V.L. Kartashova, 1972. We therefore accounted for the toxicity of the Fusarium extracts as due to the 12,13,epoxytrichothecenes. One culture of Stachybotrys alternans yielded a macrocyclic ester of 12,13-epoxytrichothecene which, upon hydrolysis, yielded verrucarol; a steroid-like molecule (SB-3) was also isolated. The former had skin-irritant activity but SB-3 did not; the latter exhibited cardiac activity on the heart of the cockroach.