Cyclopiazonic acid in combination with aflatoxins, zearalenone and ochratoxin A in Indonesian corn.

The mycotoxin, cyclopiazonic acid (CPA), was detected at concentrations as high as 9 ppm in 21 of 26 corn samples from a Bogor poultry feedmill. This is the first demonstration of the natural occurrence of CPA in Indonesia. CPA was always accompanied by other mycotoxins, especially aflatoxins, suggesting that the interactive toxicity of these mycotoxins to poultry should be investigated.

Corn as a source of mycotoxins in Indonesian poultry feeds and the effectiveness of visual examination methods for detecting contamination.

Every truck load of corn (n = 52) entering and every batch of poultry feed (n = 290) leaving a Bogor feedmill over one year was analysed for aflatoxins, zearalenone, ochratoxin A and sterigmatocystin. Fifty loads of corn and 274 of the batches of chicken feed contained aflatoxins. Zearalenone was detected in 11 corn samples but was not found in the formulated feed. Ochratoxin A was detected in one corn sample, but not in feed. Corn can account for all of the aflatoxin in the feed since levels were always lower in the finished product. There was no quantitative association between the proportion of bright green-yellow fluorescent, purple or mouldy kernels and the mycotoxin contents of the composite samples. Nevertheless, the absence of abnormal kernels indicates higher quality corn since the highest levels of mycotoxins occurred in the abnormal kernels.

Mutagenicity screening of foods. II. Results with fruits and vegetables.

A survey of the mutagenic potential of a wide variety of food products has been initiated with results for 28 different beverages reported previously [Stoltz et al, 1982b]. Here, results for samples of 46 widely consumed fruits and vegetables from six general categories are given. Each sample was concentrated and fractionated by polarity and solubility to give five fractions, each of which was assayed for mutagenic potential with Salmonella typhimurium TA98 and TA100. Although statistical analysis of the data resulted in positive findings for 22 fruit and vegetable samples, only six products (grapes, onions, peaches, raisins, raspberries, strawberries) demonstrated potent mutagenic activity.

Mutagenicity screening of foods I. Results with beverages.

Following a number of recent reports on the presence of mutagens in certain foods, a general survey of the mutagenic potential of a wide variety of food products has been initiated. Here, results for samples of 28 widely consumed beverages from 13 general categories are reported. Each sample was concentrated and fractionated by polarity and solubility to give up to seven fractions, each of which was assayed for mutagenic potential with Salmonella typhimurium TA98 and TA100 +/- fortified liver homogenate. Fractions showing evidence of either mutagenicity or toxicity were retested at the same and lower concentrations. The utility of the fractionation procedure and the sensitivity of the screening strategy were established by assaying six beverages spiked with known mutagens prior to fractionation. Statistical analysis of the data resulted in positive findings for seven beverages, although confirmation of these results through analysis of a second sample was obtained only for red wine, grape juice, and instant coffee. The remaining 21 beverages showed no strong evidence of mutagenic activity. For those foods for which the variation among replicate plates was largest, the false-positive rate for the two-stage screening procedure employed was estimated to be less than 1% while the false-negative rate for a beverage inducing a threefold increase in the background mutation rate was conservatively estimated to be limited to 14%.

Mutagens produced by Alternaria alternata.

Alternariol, alternariol methyl ether and tenuazonic acid, metabolites present in Alternaria alternata cultures, were tested for mutagenicity with Salmonella typhimurium strains TA98 and TA 100. Alternariol methyl ether was weakly mutagenic to strain TA98 (without metabolic activation). Chromatographic separations of A. alternata mycelium extract yielded several fractions mutagenic in the latter system, including the altertoxin I fraction and a purified yellow pigment C20H14O6, which was characterized spectroscopically.

Lack of enhancement of chemical mutagenesis by saccharin in the Salmonella assay.

A purified batch of the artificial sweetener saccharin (S-1022) was assayed for mutagenicity and comutagenicity by the Ames Salmonella assay system. Saccharin was not mutagenic and failed to enhance the mutagenic activity induced by a wide variety of known mutagens. These results do not argue against the tumor-promotor-like activity of saccharin but only indicate that the Ames Salmonella assay is not capable of detecting saccharin as a promoter of mutagenesis.

Toxins of molds from decaying tomato fruit.

Among 27 mold isolates from decaying tomatoes, culture filtrates or ethyl acetate extracts of 8 isolates grown in yeast extract-sucrose medium were markedly toxic (mortality, greater than 50%) to brine shrimp larvae. The toxicity of six of these isolates could be attributed to the presence of citrinin, tenuazonic acid, or T-2 toxin. Ethyl acetate extracts of five Alternaria isolates and one Fusarium isolate were mutagenic for Salmonella typhimurium strains. In ripe tomatoes inoculated with toxin-producing isolates and incubated at 25 degrees C, one Alternaria alternata isolate produced tenuazonic acid in seven of seven tomatoes at levels of up to 106 micrograms/g and alternariol methyl ether in one of the seven tomatoes at 0.8 microgram/g. Another A. alternata isolate produced tenuazonic acid or alternariol methyl ether at much lower levels in only three of seven tomatoes. Patulin and citrinin were produced by a Penicillium expansum isolate at levels of up to 8.4 and 0.76 microgram/g, respectively. In tomatoes incubated at 15 degrees C, a Fusarium sulphureum isolate produced T-2 toxin, HT-2 toxin, and neosolaniol at levels of up to 37.5, 37.8 and 5.6 micrograms/g, respectively. If these mycotoxins are thermostable, they may occur at detectable levels in tomato products whenever partially moldy tomatoes are used as raw material.

The mutagenicity of saccharin impurities. I. Detection of mutagenic activity.

Sodium saccharin, ortho-toluenesulfonamide and impurities extracted from commercially produced saccharin with water and organic solvents were tested for mutagenicity with strains of Salmonella typhimurium. The organic solvent soluble impurities exhibited strong mutagenic activity for TA98 and slight activity for TA100. Mutagenic activity for S. typhimurium TA98 was demonstrated in extracts of some but not all lots of sodium saccharin produced by both Maumee and Remsen-Fahlberg processes. The significance of the mutagenic impurity to the carcinogenicity of saccharin is discussed.

Mutagenicity induced by lyophilization or storage of urine from isoniazid-treated rats.

Urine collected during 24 h after treatment of rats with 90--550 mg/kg isonicotinic acid hydrazide (isoniazid, INH) was after lyophilization, mutagenic for Salmonella typhimurium TA1535. Urine collected directly from bladders of INH-treated rats was not mutagenic, and solutions of INH in water or urine became mutagenic only after lyophilization. In the absence of lyophilization, sterile urine from INH-treated rats became mutagenic after 8--14 days' storage at room temperature.

Mutagenicity of five cyclic N-nitrosamines: assay with Salmonella typhimurium.

The mutagenicity of five cyclic N-nitrosamines was studied with the use of Salmonella typhimurium TA1535 in vitro with and without microsomal activation. The carcinogens nitrosopiperidine and nitrosopyrrolidine required metabolic activation before manifesting mutagenic activity. Nitrosoproline and nitrosohydroxyproline, noncarcinogens, were not mutagenic. Nitroso-3-pyrrolidinol was mutagenic in the absence of microsomes, thereby suggesting a role of hydroxylation in the metabolic activation of nitrosopyrrolidine to an ultimate carcinogenic species.

Mutagenic effect of nialamide on Salmonella typhimurium.

The mutagenicity of an antidepressant drug, nialamide, was studied with Salmonella typhimurium TA1535-8. Nialamied was mutagenic for strain TA1535 in the absence of rat liver extracts.

A simple technic for repeated collection of blood samples from mice.

A device for repeated collection of small blood samples from mice was constructed from a plastic syringe. Blood was collected into a 3.33 lambda capillary tube. Bleeding was stopped by a hemostat made from a rubber stopper. This technic allows easy collection of approximately 20 serial samples within an 8-hr period.