Mycotoxin production by Fusarium oxysporum and Fusarium sporotrichioides isolated from Baccharis spp. from Brazil.
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Fusarium oxysporum isolated from roots of and soil around Baccharis species from Brazil produced the trichothecenes T-2 toxin, HT-2 toxin, diacetoxyscirpenol, and 3'-OH T-2 (TC-1), whereas Fusarium sporotrichioides from the same source produced T-2 toxin, HT-2 toxin, acetyl T-2, neosolaniol, TC-1, 3'-OH HT-2 (TC-3), iso-T-2, T-2 triol, T-2 tetraol, and the nontrichothecenes moniliformin and fusarin C. Several unknown toxins were found but not identified. Not found were macrocyclic trichothecenes, zearalenone, wortmannin, and fusarochromanone (TDP-1). (+info)
Effect of acute oral doses of T-2 toxin on tissue concentrations of biogenic amines in the rat.
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T-2 toxin [3 alpha-hydroxy-4 beta, 15-diacetoxy-8 alpha-(3-methylbutyryloxy)-12,13-epoxytrichotec-9-ene] is an emetic Fusarium trichothecene mycotoxin known to cause lethargy, ataxia and feed refusal in economically important animals. Experiments were conducted to determine the effect of acute oral doses of T-2 toxin on tissue concentrations of neurotransmitters thought to play some role in regulation of feed consumption. Sixty-seven male weanling rats were intubated with a few grams of diet in a liquid slurry with or without 2.0 mg T-2 toxin per kilogram of body weight. At 1, 2, 4, 6, 8, 12, 24 and 48 h following dosing, rats were killed, and brains, spleens, hearts and adrenal glands were excised and analyzed for concentrations of neurotransmitters and metabolites using high-performance liquid chromatography with electrochemical detection. Administration of T-2 toxin caused increases in brain concentrations of tryptophan and serotonin at the early time intervals after dosing. Brain concentrations of dopamine increased, whereas concentrations of 3,4-dihydroxyphenylacetic acid (DOPAC) decreased at the later time interals following dosing. Concentrations of dopamine were increased in adrenal glands, whereas epinephrine concentrations decreased. Epinephrine was detected in spleen and heart after administration of T-2 toxin. It was concluded that the increase in brain indoleamines induced by T-2 toxin could contribute to feed refusal in animals suffering from T-2 toxicosis. (+info)
Potential for dietary amino acid precursors of neurotransmitters to overcome neurochemical changes in acute T-2 toxicosis in rats.
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Experiments were conducted to determine the potential for overcoming T-2 toxin-induced changes in brain neurotransmitter concentrations through dietary manipulation. Rats were fed either a tryptophan-deficient, gelatin-based diet or the same diet supplemented with a mixture of large neutral amino acids for 4 d. Rats were then dosed with 0 or 2.0 mg T-2 toxin/kg body weight and killed 4, 8 or 12 h after dosing. The large neutral amino acid supplements successfully reduced brain concentrations of tryptophan and serotonin in control rats, but this was not enough to overcome the acute effects seen in T-2 toxin-treated rats. A further experiment was then conducted to monitor the effect of T-2 toxin on the ratio of free to protein-bound tryptophan in plasma. Total plasma tryptophan increased in T-2 toxin-treated rats, although there were no significant differences in the ratio of free to protein-bound tryptophan. A final experiment was conducted to determine the specificity of the T-2 toxin effect on concentrations of plasma amino acids. Concentrations of amino acids that use the large neutral amino acid transport system into the brain were higher in T-2 toxin-treated animals. The only other amino acid that had a higher concentration was arginine. It was concluded that acute doses of T-2 toxin may selectively alter membrane transport of amino acids. (+info)
Occurrence of free and conjugated 12,13-epoxytrichothecenes and zearalenone in banana fruits infected with Fusarium moniliforme.
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Three recognized 12,13-epoxytrichothecene mycotoxins, trichothecolone, diacetoxyscirpenol, and T-2 toxin, and a hyperestrogenic factor, zearalenone, together with the fatty acid esters of trichothecolone, scirpenetriol, T-2 tetraol, and zearalenone, were isolated from the flask culture extractives of Fusarium moniliforme Sheldon (IMI 225232) as well as from the fruit of banana (Musa sapientum L.) infected with the same fungus in the field and in storage. The total concentrations of these toxins in the naturally infected fruits were quite high (0.8 to 1.0 mg/g of fruit). F. moniliforme infections of banana fruits, being of wide occurrence in the world, could cause serious health problems in humans when the infected fruits are ingested for a prolonged period of time. (+info)
Effects of several mycotoxins on specific growth rate of Butyrivibrio fibrisolvens and toxin degradation in vitro.
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Four strains of Butyrivibrio fibrisolvens did not degrade aflatoxin B1. Acetyl T-2 toxin, T-2 toxin, HT-2 toxin, deoxynivalenol, diacetoxyscirpenol, verrucarin A, zearalenone, and ochratoxin A did not affect the specific growth rate of B. fibrisolvens CE51 significantly, but all were degraded to greater or lesser extents. Breakdown products were produced as a result of deacetylation reactions. (+info)
Inhibition of T-2 toxin production on high-moisture corn kernels by modified atmospheres.
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The fungus Fusarium sporotrichioides, capable of producing T-2 toxin (T-2), was grown on irradiated corn kernels remoistened to 22% and kept in atmospheres of different CO2-O2 combinations. The production of T-2 was totally inhibited under 60% CO2-20% O2, whereas only trace amounts were detected when the gas combination was 40% CO2-5% O2. Under all other combinations tested, the amount of T-2 produced was reduced by 25 to 50% as compared with the control. Fungal growth was not inhibited by any of the gas mixtures examined, and the growth rate (measured by direct plating, dilution method, and CO2 production) was almost identical to that in grains kept under air. It is concluded that although F. sporotrichioides is tolerant to high CO2 levels, T-2 formation on corn can be inhibited by CO2 concentrations less than that required to inhibit fungal growth. (+info)
Mycotoxin interactions in poultry and swine.
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Mycotoxins are toxic compounds produced by fungi. When one mycotoxin is detected, one should suspect that others also are present in a contaminated feed ingredient or finished feeds. The toxicity and clinical signs of observed in animals when more than one mycotoxin is present in feed are complex and diverse. Some mycotoxins, such as the combination of aflatoxin with either ochratoxin A or T-2 toxin, interact to produce synergistic toxicity in broiler chicks. The effects observed during multiple mycotoxin exposure can differ greatly from the effects observed in animals exposed to a single mycotoxin. For example, fatty livers in poultry are used for presumptive diagnostic identification of aflatoxicosis. However, simultaneous presence of ochratoxin A prevents fatty livers. Of the mycotoxin combinations that have been investigated in poultry and swine, the aflatoxin + ochratoxin A and aflatoxin + T-2 toxin interactions appear to be the most toxic. (+info)
T-2 toxin and diacetoxyscirpenol metabolism by Baccharis spp.
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Hybrids resulting from crosses between Baccharis sarothroides and B. pilularis (FS1), B. sarothroides (FS2) and B. megapotamica (FS3) were tested for their tolerance to trichothecenes as well as their ability to metabolize the toxins. B. sarothroides (desert broom) was placed in an aqueous solution containing 500 ppm of T-2 toxin and showed visible signs of toxicity on the twigs at 21 h after exposure but not at 6 h, indicating some resistance. Samples of the twigs harvested 6 and 21 h after treatment contained, respectively, T-2 (0.03 and 2.2 micrograms/g), HT-2 (0.09 and 7.6 micrograms/g), and T-2-tetraol (2.1 and 2.6 micrograms/g). The hybrid FS1 showed no signs of toxicity 6 h after treatment, and its twigs contained T-2 (0.8 micrograms/g), HT-2 (10.2 micrograms/g), and T-2-tetraol (10.8 micrograms/g). The leaves at 6 h contained 0.5 micrograms of T-2, 1.7 micrograms of HT-2, 0.01 microgram of 3'-hydroxy-HT-2, and 41 micrograms of T-2-tetraol per g. At 21 h, toxic signs were apparent and the twigs contained T-2 (39 micrograms/g), HT-2 (62 micrograms/g), 3'-hydroxy-HT-2 (0.8 microgram/g), and T-2-tetraol (22 micrograms/g).(ABSTRACT TRUNCATED AT 250 WORDS) (+info)