Fusarium molds

Recently, much concern has been expressed about the effect of synthetic chemicals that have estrogen-like effects. We have touched on this lightly in previous chapters and will revisit it in Chapter 7. Zearalenone is an estrogenic mycotoxin produced by a number of species of Fusarium mold. It has caused a number of abnormalities in the reproductive system in animals and possi-... 

The first crop in North America to be surveyed for vomitoxin was the 1980 wheat from eastern Canada (1). Soft winter wheat harvested in Ontario was noticed to contain pink kernels this is one of the signs that the Fusarium mold which produces vomitoxin causes when it invades the kernels. Forty-four of 45 samples analyzed contained vomitoxin in concentration ranging from 0.01 to 4.3 parts per million (ppm). In Quebec, the contamination was worse. One hundred per cent contamination of the hard spring wheat crop was found based on analyses of 27 samples. Eighty five per cent of the samples contained greater than 0.3 ppm. 

In the U.S., routine analysis of grains for vomitoxin didn t begin until 1981, about a year after the Canadians first surveys. In 1981, the U.S. cornbelt was heavily contaminated with vomitoxin from Iowa to New York. In Illinois, 274 of 342 samples of grain (mostly corn, but some wheat and oats) and animal feeds were found to contain from 0.1 to 22 ppm with a mean of 3 ppm vomitoxin ( ) In 1982, the winter wheat crop of Kansas, Nebraska, Missouri and Iowa was contaminated with vomitoxin. A million acres of land in southeast and southcentral Nebraska (one third of the Nebraska wheat producing area) contained scabby wheat, a condition caused by the Fusarium mold that produces vomitoxin. A survey of 87 samples of wheat heads, grain, chaff, and straw found 76 (87%) to contain over 0.3 ppm, 63 (72%) over 1 ppm and 11 (13%) over 5 ppm vomitoxin (4). The scabby wheat area extended into north-... 

Trichothecences are a class of structurally similar mycotoxins produced principally by Fusarium molds. These cyclic compounds are of interest to feed manufacturers because they can cause feed refusal or reduced feed efficiencies in some animal species (1,2,3). Several approaches have been reported for the analysis of trichothecenes in feeds and feed ingredients. Trimethylsilyl derivatives of the trichothecenes have been formed and the derivatives measured by gas chromatography using a flame ionization detector (4,3,6,7). Other workers obtained improved... 

While some biological toxins can be synthesized artificially, the practical method for producing these poisonous substances is to extract them from living organisms. For example, botulinum toxin is the active poison in the bacterium Clostridium botulinum. Trichothecene or T2 toxin is derived from species of Fusarium mold, and is unique among BW agents for its ability to cause pain and injury on contact with unprotected skin. 

Rapid-acting dermally hazardous cytotoxin that inhibits protein synthesis and affects clotting factors in the blood. It is capable of producing incapacitating or lethal effects. T2 is obtained from various molds and fungi (Fusarium sp.). It is a colorless crystalline solid of white powder that melts at 304°F. Impure samples may be a colorless to slightly yellow oil. It is slightly soluble in water, but soluble in ethyl acetate, acetone, ethanol, chloroform, methylene chloride, diethyl ether, and dimethyl sulfoxide (DMSO). It is heat stable and can be stored at room temperature for years. 

Dermally hazardous cytotoxins obtained from various molds and fungi (Fusarium sp.). They are colorless, crystalline solids that are heat stable and can be stored for long periods. 

Trichothecene mycotoxins are produced by a number of fungal molds of the Fusarium, Myrotecium, Trichoderma, and Stachybotrys genera. They inhibit protein synthesis, impair DNA synthesis, and interfere with cell membrane structures and functions. The potential routes of exposure are inhalation, ingestion, and skin absorption. A terrorist may take advantage of any of these routes. 

When consumed, the combread is often contaminated with the mold Fusarium moniliforme, and it has been shown (150,151) that this mold, in the presence of nitrite, will elaborate a range of IV-nitroso compounds Me2NNO, Et2NNO, Me(PhCH2)NNO, and (Me2CHCH2CH2)-(CH3COCHMe)NNO. Combread contaminated in this way induces tumors in rats (150). 

The asparaginase from the mold Fusarium tricinctum, also without antilymphoma activity, has been purified to apparent homogeneity, although its amino acid composition has not yet been established (40). It is perhaps worth noting that it has been found to contain both galac-tosamine and glucosamine. 

By keeping ethylene concentrations to less than 0.8 ul/1 of air, stem-end decay caused by a species of Fusarium, green mold, loss of orange flavor, and development of off-flavors were minimized. Other volatiles present with and without the ethylene absorber apparently had no effect on quality. Ethylene, produced in copious quantities by rots, enhances respiration and senescence of healthy fruit within the storage facility (281). The importance of ethylene removal has been illustrated also in recent storage studies of lemons in Australia (282, 283, 284, 285). 

Trichothecenes are composed of 40 or more structurally related compounds produced by a variety of molds, including Cephalosporium, Fusarium, Myrothecium, and Trichoderma, which grow predominantly on grains. Much of the available information on human toxicity of trichothecenes was obtained from an outbreak of poisoning in Siberia in 1944, mentioned above. 

Vert et al. exposed compression-molded racemic PDLLA to a mixed culture of Fusarium moniliforme and Pseudomonas putida at 30 °C [63]. The polymer... 

Comparisons of sensitization rates to various basidiomycetes, and between basidiomycetes and other groups of fungi have been made in the frame of skin test surveys [20-22]. In a multicenter study in Europe and the USA, it was shown that sensitization to basidiomycetes was as prevalent as sensitization to other well-established allergenic molds, such as Altemaria, Cladosporium, Aspergillus and Fusarium [21]. Generally, 25-30% of subjects with respiratory... 

Micafungin has activity against Candida, including azole-resistant C. albicans. It has some activity against molds such as Aspergillus but no activity against Fusarium. 

Plant wilts while soil is moist. Cause Fusarium wilt. Fusarium spp. fungi sometimes infect astilbes, causing wilting unrelated to adequate soil moisture. Young plants wilt quickly, while older ones turn pale green and lower leaves wilt. Stems show brown streaks that darken gradually grayish pink mold may appear. Remove and destroy infected plants... 

The US Food and Drug Administration has set regulatory limits for aflatoxins produced by Aspergillus flavus. Health Canada has set limits for zearalenone (from Fusarium and some other molds). However, the majority of mycotoxins do not have regulatory limits. 

---