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PubMed1975

Action of the mycotoxin of Fusarium sporotrichiella v. sporotrichioides on lysosomal membranes.

The effect of the mycotoxin of Fusarium sporotrichiella v. sporotrichioides (sporofusarin) was studied in vitro on the total and nonsedimenting activity of eight lysosomal enzymes: acid ribonuclease, aryl sulfatases A and B, beta-glucuronidase, alpha- and beta-galactosidases, beta-glucosidase, beta-acetylglucosaminidase, and alpha-mannosidase. Incubation of a suspension of rat liver lysosomes with an aqueous solution of sporofusarin led to inhibition of the total activity of the membrane-bound lysosomal enzyme beta-glucosidase. In a dose of only 1.6 x 10-5 M sporofusarin caused a significant increase in the nonsedimenting activity of nearly all the enzymes; in a concentration of 1.6 x 10-3 M most of the enzymes of the lysosomal matrix (beta-glucuronidase, beta-galactosidase, aryl sulfatases A and B) were liberated almost completely into the supernatant, and nearly all the beta-glucosidase also was liberated. It is postulated that damage to the subcellular membranes is an important component of the toxic action of sporofusarin.

Animals↗
PubMedDate not supplied

Analysis and screening for mycotoxins and other secondary metabolites in fungal cultures by thin-layer chromatography and high-performance liquid chromatography.

Methods for the screening of fungal cultures for toxic secondary metabolites are reviewed. Thin layer chromatography (TLC) and high-performance liquid chromatography (HPLC) are good general analytical methods for secondary metabolites in unpurified extracts. The combination of normal phase TLC using different chemical spray reagents with reversed phase HPLC, using alkylphenone retention indices and diode array detection, is a powerful technique for identifying the individual mycotoxins detected. The results of the screening methods are very dependent of the growth media and incubation conditions and a general method for the detection of Penicillium, Aspergillus, Fusarium, Alternaria and Cladosporium toxins is suggested.

Chromatography, High Pressure Liquid↗
PubMed1995

Mycotoxins and fungi in wheat harvested during 1990 in test plots in the state of São Paulo, Brazil.

Wheat from two cultivars with contrasting characteristics were harvested in ten experimental plots located in wheat producing areas of the State of São Paulo, Brazil. The samples (10 of each cultivar) were analyzed by a gas-chromatographic method for deoxynivalenol (DON), nivalenol (NIV), diacetoxyscirpenol (DAS), toxins T-2 (T-2) and HT-2, T-2 tetraol, T-2 triol, and by a thin-layer chromatographic method for zearalenone (ZEN), aflatoxins B1, B2, G1, G2, ochratoxin A and sterigmatocystin. No mycotoxins were detected in 13 samples. DON was found in four samples (0.47-0.59 microgram/g), NIV in three samples (0.16-0.40 microgram/g), T-2 in two samples (0.40, 0.80 microgram/g), DAS in one sample (0.60 microgram/g), and ZEN in three samples (0.04-0.21 microgram/g). The wheat samples were also examined for the incidence of fungi. Alternaria, Drechslera, Epicoccum and Cladosporium were the prevailing genera. Among the Fusarium spp., F. semitectum was present in 19 samples and F. moniliforme in 18 samples. No F. graminearum was isolated in the samples.

Aflatoxins↗
PubMed1993

Fungal flora and mycotoxins of six kinds of nut seeds for human consumption in Saudi Arabia.

A wide range of moulds representing several genera and species, was recorded in this study from 5 seed samples of each almond, cashew nut, chestnut, hazelnut, pistachio nut and walnut collected from different markets in Ar' Ar, Saudi Arabia. The total counts of fungi were widely fluctuated between 1960-7704 and 1948-7434 colonies/g dry seeds on glucose-Czapek's and glycerol agar media at 28 degrees C, respectively, and represented twenty genera, 53 species and 2 varieties of fungi. The prevalent fungi on the 2 agar media were Aspergillus flavus, A. niger and Penicillium chrysogenum. On glucose-Czapek's agar, Rhizopus stolonifer and Aspergillus flavus var. columnaris were isolated from all 6 kinds of nut, A. parasiticus from 5 kinds and A. fumigatus from 4 kinds with high frequencies. Eurotium species were completely absent on glucose-Czapek's agar but they were isolated in high frequency from all kinds of nut on glycerol agar medium. The different nut samples were analyzed by thin layer chromatography for the presence of aflatoxins B1, B2, G1 & G2, citrinin, ochratoxins, patulin, sterigmatocystin, diacetoxyscirpenol, T-2 toxin and zearalenone. Aflatoxins B1 & G1 were detected in 3 out of the 5 samples tested of chestnut at concentrations ranging between 20 to 60 micrograms/kg. All other samples of almond, cashew nut, hazelnut, pistachio nut, and walnut that were analyzed were mycotoxin free.

Food Microbiology↗
PubMed1994

Mycoflora, and mycotoxins production in Nigerian corn and corn-based snacks.

Thirty-one fungal species, mostly toxigenic and belonging to 11 genera were isolated from corn, corn cake and corn roll snack samples. Aspergillus, Penicillium and Fusarium accounted for 10, 6 and 3 of the species and altogether, they constituted 90, 94 and 88 percent of the total fungi in corn, corn cake and corn roll snack respectively. Mycotoxins (aflatoxins and ochratoxin A) were detected in 45, 80 and 12 percent while the means and ranges of the total aflatoxins recorded were: 200(25-770 ppb); 233(15-1070 ppb) and 55(10-160 ppb) for corn, corn cake and corn roll snack samples respectively. Ochratoxin A was detected at toxicologically significant levels in only 15 percent of the corn cake samples analyzed. All the strains of Aspergillus flavus and A. ochraceus tested produced aflatoxin B and ochratoxin A, respectively, when they were cultured on each of the three substrates. In each case, substantial quantities of the toxins were produced from 25 to 35 degrees C with the peak level recorded at 30 degrees C. Toxin production was detected only in substrates with 15 percent moisture content and above; reaching the maximum at 25 or 30 percent moisture level. No substantial differences in the amount of toxins were elaborated with further increase in substrates' moisture content. Of the three substrates, corn cake was the most suitable for aflatoxin B production while they were all equally suitable for the elaboration of ochratoxin A.

Aflatoxin B1↗
PubMed1995

Occurrence of mycotoxins in cereals and animal feedstuffs in Natal, South Africa 1994.

During the year of 1994, 417 samples of agricultural commodities, comprising: maize, compound animal feeds, oil seeds, soya bean, fish meal and forage were examined for fungi and over 20 mycotoxins using a multi-screen augmented with individual assays. Trichothecenes had the highest incidence of over 19% in all samples received, followed by aflatoxin at 6% and then zearalenone at 3%. Selected samples (73) were analyzed for fumonisin B1 and of these, 69 (94%) were found to be positive. Because of this result and high incidence of Fusarium spp. (over 70%) in maize and maize containing feeds, which was higher than either Aspergillus spp. (19%) or Penicillium spp. (33%), attention is drawn to the actual and potential presence of fumonisin in the food chain.

Animal Feed↗
PubMed1995

Fungal contamination and selected mycotoxins in pre- and post-harvest maize in Honduras.

Sixty nine samples of maize were collected from pre-harvest standing crops and on-farm storage facilities from 52 smallholder farms located within 4 regions of Honduras during October 1992 and November 1993. Samples were visually assessed for insect damage and fungal spoilage, and the mycoflora quantified on artificial media. The major components of the ear rot complex were: Fusarium moniliforme, F. moniliforme var. subglutinans, Penicillium species, Stenocarpella maydis, S. macrospora and Acremonium spp. Representative samples were also assayed for mycotoxin content. Fumonisin B1 was detected in all 24 samples tested at levels of between 68-6,555 (micrograms/kg), and aflatoxin was detected in 2 samples heavily contaminated with Aspergillus flavus. Moniliformin and tenuazonic acid were not detected in the samples tested. The implications of these findings for human and livestock health risk are discussed, together with possible strategies for controlling these pathogens.

Aflatoxins↗
PubMed1981

[Effect of mycotoxins on the rate of fermentation in Saccharomyces cerevisiae].

The rate of fermentation of Saccharomyces cerevisiae is partially inhibited by different mycotoxins. This effect is remarkable with T2-toxin and diacetoxyscirpenol, slight with aflatoxin-B1, penicillic acid and patulin. On the contrary, the butenolide appears as a stimulator of the alcoholic fermentation.

4-Butyrolactone↗
PubMed1994

Temporal and dose-response features in swine fed corn screenings contaminated with fumonisin mycotoxins.

Fumonisin B1 (FB1), a mycotoxin produced by Fusarium moniliforme and F. proliferatum, induces liver damage and pulmonary edema in swine. We examined the temporal and dose-response features of FB1 toxicosis in male weanling crossbred pigs fed nutritionally balanced diets, containing corn screenings naturally contaminated with fumonisins, for 14 days. Total fumonisins (FB1 and FB2) in diets 1 through 6 were assayed at 175, 101, 39, 23, 5, and < 1 ppm (below detectable concentrations), respectively. Clinical signs, serum biochemical alterations, and morphologic changes were evaluated. Pigs were weighed, and bled for hematologic and clinical chemistry evaluation on days 5 and 14. They were euthanized on day 14, or earlier if respiratory distress was observed. Respiratory distress developed in 3/5 pigs fed diet 1 between days 4 and 6 due to severe pulmonary edema and pleural effusion. Histologic evidence of hepatic injury was present in all pigs fed diets 1 and 2, 3/5 on diet 3, and 1/5 on diet 4. Serum bilirubin and cholesterol concentrations, gamma-glutamyl transferase (GGT), alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and arginase (ARG) activities were elevated in pigs fed diets 1 and 2. Based on liver histopathology, the no observed adverse effect level (NOAEL) for fumonisin toxicity in swine was < 23 ppm total fumosins for the 14-day period. Based on regression analyses of the clinical chemistry profiles at 14 days, the NOAEL was < 12 ppm, with ALP being the most sensitive parameter. In conclusion, pulmonary edema occurred only at the highest fumonisin concentration (175 ppm), while liver damage occurred at much lower concentrations with a NOAEL of < 12 ppm.

Animal Feed↗
PubMed1976

[Danger to human health from mycotoxins].

The review paper summarizes our knowledge on the influence of the intake of mycotoxin containing foodstuffs on human health. The greatest attention is given to the aflatoxins. The results of epidemiological studies on the occurrence of primary liver cancer in Thailand and different regions of middle and southern Africa are described.

Aflatoxins↗
PubMed1994

Occurrence of Fusarium sacchari var. subglutinans and its mycotoxin production ability in broiler feed.

Spores of Fusarium sacchari var. subglutinans isolated from broiler feed BR1 were obtained at an average concentration of 1.5/mg in 25% of tested samples. The spore concentration was increased from 1 to 100/mg of solid substrate (BR2; biscuit) or to 1/nL of Sabouraud broth after 3 weeks of cultivation. Mycotoxin analyses of these three substrates showed negative reactions for T-2 toxin and zearalenone but a positive reaction for deoxynivalenol (DON) which was found in concentrations of 5 ppm in Sabouraud broth, 50 ppm in BR2 and 220 ppm in biscuit. Therefore, our F. sacchari isolate appeared to be a DON producer.

Animal Feed↗
PubMed1995

Natural occurrence of mycotoxins in different spices in Egypt.

A total of 120 different samples belonging to 24 kinds of species collected from different places at Assiut Governorate (Egypt) were examined for the natural occurrence of mycotoxins. TLC analysis of spice extracts revealed the presence of aflatoxins (8-35 micrograms/kg) in 16 samples of anise, black pepper, caraway, black cumin, fennel, peppermint, coriander and marjoram, sterigmatocystin (10-23 micrograms/kg) in ten samples of red pepper, caraway, cumin and marjoram and citrinin (8-12 micrograms/kg) in two samples of black cumin, while ochratoxin A and zearalenone could not be detected.

Aflatoxins↗
PubMed1994

Effect of mycotoxins on in vitro movement of tracheal cilia from one-day-old chicks.

The effect of 11 mycotoxins on the ciliary movement of tracheal epithelium from one-day-old chicks in vitro was examined. Sterigmatocystin and diacetoxyscirpenol were most ciliostatically active in vitro; the ciliostatic effect was observed after 2 d if the amount concentration was 30 micrograms/L. In contrast, patulin stopped the movement of cilia after 2 d only if its concentration was 20 mg/L.

Aflatoxins↗
PubMed2000

Mycotoxin production on rice, pulses and oilseeds.

Mycotoxin-producing fungi were isolated from contaminated grains of rice, pulses and oilseeds sold in the local markets of Calcutta for human consumption. It was found that aflatoxin B1 was produced by Aspergillus flavus and Aspergillus parasiticus, aflatoxin G1 by A. flavus, ochratoxin by Aspergillus ochraceous, sterigmatocystin by Aspergillus japonicus and citrinin by Penicillium citrinum. Aflatoxin B1 (333-10,416 micrograms/kg) was produced by Aspergillus spp. in rice, pulses and oilseeds.

Aflatoxin B1↗
PubMed2003

Effects of the mycotoxin ochratoxin A in a bacterial and a mammalian in vitro mutagenicity test system.

Ochratoxin A (OTA), a mycotoxin produced by several Aspergillus and Penicillium species, is a worldwide contaminant of food and feedstuffs. It is nephrotoxic, immunosuppressive and carcinogenic in several animal species. The mechanism by which OTA acts is not fully understood up to now. Here, OTA was evaluated for mutagenicity in the Salmonella typhimurium assay (Ames assay) and in the HPRT assay with V79 hamster fibroblasts. In the bacterial assay using the strains TA 98, TA 100, TA 1535, TA 1538, TA 102 and TA 104, OTA was not mutagenic at a concentration range from 0.01 to 500 micro M in the presence and absence of an external metabolising enzyme system (rat liver S9 enzyme mix). In V79 fibroblasts, cytotoxicity of OTA was estimated with the neutral red uptake assay. An IC(50) of 11.6 micro M was found in the absence and an IC(50) of 6.4 micro M in the presence of S9 mix. In the subsequent HPRT (hypoxanthine-guanine-phosphoribosyl-transferase) assay with V79 cells the negative result of the bacterial assay was confirmed using OTA in concentrations from 0.1 to 100 micro M. In order to obtain converted OTA metabolites from viable, metabolically competent cells, a preincubation of primary cultured rat hepatocytes with 0.016 to 0.8 micro M OTA was performed. The resulting culture medium, which contained OTA metabolites, was tested in both mutagenicity assays. Again, no mutagenic effect was detected either in the bacterial or in the mammalian test assay. In accordance with several literature data, the present results imply that OTA does not act as direct mutagen. Additionally, the OTA metabolites derived from cultured rat hepatocytes or rat liver S9 mix, also, do not have a mutagenic potency in the test systems used.

Animals↗
PubMed2006

Cloning and expression of Penicillium minioluteum dextranase in Saccharomyces cerevisiae and its exploitation as a reporter in the detection of mycotoxins.

A dextranase gene from Penicillium minioluteum (strain IMI068219) has been cloned, sequenced and expressed in Saccharomyces cerevisiae via fusion of the DNA segment encoding the mature dextranase protein with alpha-factor signal sequence, and insertion into the GAL1-controlled expression vector pYES2/CT. Galactose-induced expression yielded extracellular dextranase activity of 0.63 units/ml and cell-associated dextranase activity of 0.48 units/ml, after 24 h incubation. The dextranase construct was introduced into a strain of S. cerevisiae expressing the human cytochrome P450 3A4 (CYP3A4) and the cognate reductase, which was then used to develop a microplate toxicity bioassay. Toxicity was signalled as inhibition of dextranase activity, assayed fluorimetrically. This novel bioassay was assessed using six economically significant mycotoxins.

Aflatoxin B1↗