Biotic and abiotic factors limiting efficacy of Bt corn in indirectly reducing mycotoxin levels in commercial fields.

Incidence of insect damage, and association of insect damage with mycotoxigenic corn ear molds and mycotoxins was examined in commercial fields of Bt and non-Bt hybrids of different backgrounds in Illinois in 1998 and 1999. Nearly 50% Helicoverpa zea (Boddie) infestation sometimes occurred in Bt hybrids that express high levels of the protein in silks and kernels. Damage by European corn borer, Ostrinia nubilalis Hübner, was uncommon, even in non-Bt ears. Levels of total fumonisins were generally less (15- to 1.8-fold) in Bt versus non-Bt hybrids at the same site, with some significant differences. There were several instances where there were no significant differences in fumonisin levels between low/no Bt kernel hybrids and Bt hybrids that produced high levels of the protein in the kernel and silk tissue. However, significant correlations were often noted between numbers of insect-damaged kernels and total fumonisin levels, especially in 1998, suggesting in these cases that reducing insect damage was still reducing fumonisin levels. There was variability between the correlation coefficient for numbers of insect damaged kernels and fumonisin levels at different sites for the same year, different hybrids at the same site, and the same hybrid for different years. Although reductions in fumonisins in Bt hybrids were more limited than reported in the past, planting the Bt hybrids still appears to be a useful method for indirectly reducing mycotoxins in corn ears.     

Effects of Fusarium culmorum head blight on mycotoxin accumulation and yield traits in barley doubled haploids

The susceptibility of barley doubled haploids (DH) to Fusarium head blight (FHB) was investigated. Heads of 24 DH lines (11 two-rowed and 13 six-rowed) derived from F₁ Maresi (two-rowed) × Pomo (six-rowed) hybrids were inoculated with a conidial suspension of the single isolate IPO348-01 of Fusarium culmorum. The experiment was carried out in three consecutive years (1996–98) in one location. The number of kernels per ear, 1000-kernel weight and kernel weight per ear were recorded in inoculated and control plots. In the infected kernels nivalenol (NIV) content and deoxynivalenol (DON) content were determined. The effects of genotype, year and genotype-year interaction on reduction of yield traits were significant. For mycotoxin content only genotype and year effects were found to be important. The average NIV concentration in kernels of inoculated lines ranged from 0.15 mg/kg in the two-rowed line MP7 to 6.36 mg/kg in the six-rowed line MP113. A low accumulation of DON was observed in the studied population (from 0.01 to 0.20 mg/kg). Generally, no significant differences in mycotoxin content were found between two-rowed and six-rowed genotypes. The line MP7 was found to be superior — with the lowest mycotoxin accumulation, and reduction in yield traits. Environmental conditions (years) affected DON and NIV level in kernels; however, the tendency to a lower or higher accumulation of mycotoxin in individual lines was stable over the years.     

Deoxynivalenol and Acetyldeoxynivalenol Accumulation in Field Maize Inoculated with Fusarium graminearum

Seven selected maize hybrids (Smolimag, Ruten, KLG 2210, Zenit, Betulisa, RAH BE 86101 and RAH BE 90102) were toothpick inoculated in the ear (at ∼ 10 days after midsilk) with a single isolate of Fusarium graminearum in order to determine their reaction to infection and susceptibility to mycotoxin accumulation in the tissues. Deoxynivalenol (DON), 15-acetyldeoxynivalenol (15-AcDON), and 3-acetyldeoxynivalenol (3-AcDON) were detected in differing amounts in kernels, husks, stalks (nodes and internodes) and roots. DON was recovered from stems, husks and damaged kernels at levels of 864, 278 and 93mg/kg, respectively, while 15-AcDON was recovered at 235, 55 and 11mg/kg and 3-AcDON was recovered at 3, 2 and 0.5 mg/kg, respectively. Maize hybrids Smolimag and Ruten were most resistant to infection and contained the lowest amounts of mycotoxins in the tissues while Zenit, RAH BE 90102, RAH BE 86101 and Betulisa were most susceptible to infection and accumulated higher amounts of mycotoxins.     

Cumulation of mycotoxins in maize cobs infected with<Emphasis Type="Italic">Fusarium gramihearum</Emphasis>

Maize cobs withFusarium ear rot were collected at 1986 season and five infected byFusarium graminearum were analyzed for presence of triohothecenes and zearalenone. Collected material was subsampled forFusarium damaged kernels and corresponding axial stems and healthy looking kernels. All investigated cobs contained deoxynivalenol (DON) (range 18.0–131.5 mg/kg) and zearalenone (ZEA) (range 0.38–2.17 mg/kg), in four cobs 15-acetyl-deoxynivalenol (15-AcDON) (range 5.2–6.2 mg/kg) was present and two cobs besides three all metabolites contained 3-acetyl-deoxynivalenol (3-AcD0N) (range 0.5–0.8 mg/kg).The average of individual toxins amount in axial stems: in mg/kg was equal to: DON — 110.36, ZEA — 4.57, 15-AcD0N — 16.66, and 3-AcD0N — 1.32.Fusarium damaged kernels contained in average the following amount (mg/kg) of: DON 77.00, ZEA 0.98, 15-AcD0N 3.78 and 3-AcD0N 0.06. Healthy looking kernels contained DON 1.96 mg/kg and ZEA 0.07 mg/kg only. Cooccurrence of 3-AcDON and 15-AcDON in two samples was an interesting finding. The amount of DON in total cob was highly correlated (r = 0.94) with percentage ofFusarium damaged kernels in given ear.     

Corn earworm,Helicoverpa zea (Lepidoptera: Noctuidae) and other insect associated resistance in the maize inbred Tex6

A 2-yr field and laboratory study investigated insect resistance of the maize, Zea mays L., inbred Tex6, which has previously demonstrated resistance to Aspergillus ear rot and aflatoxin production, relative to susceptible inbred B73. Field studies indicated significantly greater resistance to insect feeding of V4-V8 growth stage Tex6 plants compared with B73 plants in both years, primarily to flea beetles (Chaetonema spp.). Field studies of natural (1999) and artificial (2000) infestations of corn earworms, Helicoverpa zea (Boddie), indicated much lower levels of kernel damage at milk stage (approximately three-fold) and smaller surviving larvae (approximately three-fold) in Tex6 compared with B73 ears. At harvest similar trends in reduction of numbers of damaged kernels per ear, as well as incidence and numbers of kernels per ear symptomatically infected by Fusarium spp. were noted. Laboratory studies indicated little difference in mortality or survivor weight of caterpillars or sap beetle adults caged with milk stage kernels of the two inbreds. However, assays with silks indicated significantly greater mortality of H. zea in both 1999 and 2000, and European corn borer, Ostrinia nubilalis (Hübner) in 1999 (only year tested) when fed Tex6 silks compared with B73 silks. Pollinated Tex6 silks were generally darker colored and more toxic than unpollinated silks. Thus, it is possible that commercially usable inbreds with resistance to insects, which also contribute to the mycotoxin problem through vectoring and damage, could be produced using Tex6 as a source.     

Indirect reduction of ear molds and associated mycotoxins in Bacillus thuringiensis corn under controlled and open field conditions: utility and limitations

In 1995, ears of a experimental inbred (CG59-2) containing a synthetic Bacillus thuringiensis Cry IA (b) gene driven by PEPC, pith and pollen promoters and artificially infested with Ostrinia nubilalis (Hübner) larvae in small plot studies were free from insect damage, whereas 40-50% of the corresponding non-Bt inbred ears were damaged. Bt inbred ears that were inoculated with Aspergillus flavus Link and Fusarium proliferatum T. Matsushima (Nirenberg) or exposed to natural mold inoculum after infestation with O. nubilalis were free of visible signs of mold, as compared with approximately 30-40% of the non-Bt ears similarly treated. Results in 1996 using the same inbred with a single allele dose of the Bt gene showed similar trends. Mean total fumonisin levels for non-Bt versus Bt inbred ears were not significantly different (2.8 versus 0.8 ppm, respectively) in 1996. In paired hybrid studies run in 0.4-ha (1-acre) fields, an event 176 Bt hybrid had significantly lower amounts of damage and signs of Fusarium spp. mold, but not fumonisin, compared with a corresponding non-Bt hybrid from 1996 to 1998. However, two hybrid pairs that contained either MON810 or Bt11 constructs examined in similar fields at the same site had lower levels of fumonisin in both 1997 (30- to 40-fold) and 1998. High intrafield variability in insect infestation and presence of Helicoverpa zea (Boddie) in Bt hybrids was apparently responsible for fewer significant differences in fumonisin levels in 1998. Similar trends for all three hybrid pairs were noted in small plot trials at another site. Incidence of other ear pests or insect predators varied as much among non-Bt hybrids as they did for Bt/non-Bt hybrid pairs.     

Aflatoxin Contamination of Preharvest Corn as Influenced by Timing and Method of Inoculation

Four corn (Zea mays L.) hybrids were grown in 1977 and 1978 and inoculated with Aspergillus flavus Link 20 or 40 days after silking. Inoculation methods included needle, knife, and multiple-puncture injury to the kernels. The level of aflatoxin contamination, insect damage to the ear, and the percentage of ears having visible greenish A. flavus Link-type mold were determined. Differences among hybrids were not significant for any of the three characteristics measured, although aflatoxin levels of the early-maturing, loose-husked hybrids were approximately twice as high as those of two later-maturing, tight-husked types. Differences among treatments for insect damage rating were not statistically significant. Delaying inoculation until 40 days after silking significantly reduced the aflatoxin contamination level of samples harvested at maturity. Fewer than one-half the ears inoculated at 40 days after silking (35.3%) exhibited visible signs of infection compared with ears inoculated 20 days after silking (82.9%). The needle inoculations were less effective in eliciting aflatoxin production (163 μg/kg and 45.1% visibly infected ears) than were knife (202 μg/kg and 61.8% visibly infected ears) and multiple puncture (305 μg/kg and 70.4% visibly infected ears) methods of inoculation.     

Moniliformin Accumulation and other Effects of Fusarium avenaceum (Fr.) Sacc. on Kernels of Winter Wheat Cultivars

Accumulation of the mycotoxin moniliformin (MON) and other effects on kernels were examined in 13 Polish winter wheat cultivars inoculated with F. avenaceum (Fr.) Sacc. isolate ATCC 64451. Kernels from inoculated ears were divided into three fractions: Fusarium damaged kernels (FDK), kernels with black point symptoms (BPK) and healthy looking kernels (HLK). The average moniliformin content (mg/kg) was highest in chaff (11.69), lower in infested kernels (FDK + BPK) (2.70) and lowest in HLK (1.16). The mean level (mg/kg) of moniliformin in kernels (total sample) ranged from 0.78 in cv. Liwilla to 3.84 in cv. Gama. Moniliformin levels in chaff were correlated ( r = 0.5322) with the average metabolite concentration (mg/kg) in kernels, and ranged from 4.97 in chaff of cv. Roma to 22.9 of cv. Alba. The moniliformin concentration in kernels (total sample) was highly correlated with the level of the metabolite in diseased kernels. This is the first report of the relationship of black point symptoms with F. avenaceum colonization of kernels and moniliformin accumulation.     

Distribution of trichothecene mycotoxins in maize ears infected withF. graminearum andF. crookwellense

Maize ears naturally infected withF. graminearum (6 samples) andF. crookwellense (6 samples) were collected in 1990 and 1991. All samples exhibited symptoms of severe ear rot with high percentage ofFusarium damaged kernels. Thousand kernels weight ranged 108.5 – 235.0g and was significantly lower than in control, not infested kernels (330g). All ears were contaminated withFusarium toxins but DON and NIV were the most frequently analyzed metabolites. Distribution of trichothecene mycotoxins in different parts of ear as well as toxicity of extracts toArtemia salina is reported in this paper.     

Simultaneous occurrence of mycotoxins in human food commodities from Cameroon

Eighty-two samples of dried food commodities from Cameroon were screened and quantified for different mycotoxins, including fumonisin B₁ (FB₁), zearalenone (ZEA), deoxynivalenol (DON), aflatoxin (AF) and ochratoxin A (OTA), by thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC), respectively. The percentage of positive samples was as follows: FB₁ 41%, AF 51%, ZEA 57%, DON 65% and OTA 3%. High FB₁ contents were found in maize, averaging 3,684 μg/kg (range: 37-24,225 μg/kg), whereas the highest average ZEA level was found in peanuts (70 μg/kg), followed by maize (69 μg/kg), rice (67 μg/kg) and beans (48 μg/kg) with no ZEA was detected in soybeans. DON contents were low, ranging from 13 to 273 μg/kg, and for AF the average content was 2.6 μg/kg with peanuts and maize as principal substrates. The incidence of OTA was low, with a mean level of 6.4 μg/kg recorded. The majority (79%) of samples contained more than one mycotoxin and the most frequent co-occurrence found was FB₁ + ZEA + DON, detected in 21% of samples (mainly maize) analysed. Co-contamination with FB₁ + ZEA + DON + AF was found in 11% of the samples. Although a large proportion of samples had fairly low levels of individual mycotoxins, this should be of concern as the co-occurrence of mycotoxins may generate additive or synergistic effect in humans, especially if the respective commodities are consumed almost on a daily basis.     

Influence of kernel age on fumonisin B1 production in maize by Fusarium moniliforme.

Production of fumonisins by Fusarium moniliforme on naturally infected maize ears is an important food safety concern due to the toxic nature of this class of mycotoxins. Assessing the potential risk of fumonisin production in developing maize ears prior to harvest requires an understanding of the regulation of toxin biosynthesis during kernel maturation. We investigated the developmental-stage-dependent relationship between maize kernels and fumonisin B1 production by using kernels collected at the blister (R2), milk (R3), dough (R4), and dent (R5) stages following inoculation in culture at their respective field moisture contents with F. moniliforme. Highly significant differences (P 相似文献   

The effect of vitamin E supplementation on reduction of lymphocyte DNA damage induced by T-2 toxin and deoxynivalenol in weaned pigs

The objective of the present study was to establish the effect of deoxynivalenol (DON) and T-2 toxin on lipid peroxidation, lymphocyte DNA fragmentation and immunoglobulin production in weaned pigs, and furthermore, to evaluate the potential of vitamin E (α-tocopheryl acetate) in prevention of toxin mediated changes. Forty-eight weaned castrated male crossbred pigs (mean live weight at the beginning of the experimental period was 11.7 kg) were randomly assigned to five experimental groups: control (without toxin and vitamin E), T-2 (3 mg/kg T-2 toxin), T-2 + E (3 mg/kg T-2 toxin + 100 mg/kg vitamin E), DON (4 mg/kg DON) and DON + E (4 mg/kg DON + 100 mg/kg vitamin E). After 14 days of treatment blood was collected for analysis. Lipid peroxidation was studied by assays of malondialdehyde (MDA), total antioxidant status (TAS) of plasma and erythrocyte glutathione peroxidase (GPx). DNA damage in lymphocytes was measured by comet assay. Serum immunoglobulin levels were evaluated by enzyme-linked immunosorbent assay (ELISA) and the hepatotoxicity was studied by measuring plasma liver enzyme levels (alanine aminotransferase (ALT), aspartate aminotransferase (AST) and γ-glutamyl-transferase (GGT). Production parameters of both DON groups were significantly impaired in comparison to the control. DON significantly increased the amount of DNA damage in lymphocytes by 28%. Moreover, the levels of TAS were lowered by addition of DON. T-2 toxin significantly impaired daily live weight gain and feed conversion, increased the amount of DNA damage in lymphocytes by 27%, decreased total serum IgG and did not alter plasma TAS. Plasma and 24-h urinary malondialdehyde (MDA) excretion rate and erythrocyte Gpx levels did not differ among the groups. Supplementation with vitamin E did not improve production parameters impaired by DON and T-2 toxin and only partially protected lymphocyte DNA from toxin impact. To our knowledge, these are the first data on genotoxic effects of moderate doses of DON and T-2 toxin on pig lymphocytes. The effect of DON and T-2 toxin on the immune system was reflected as a change in immunoglobulin synthesis, which might be toxin and species specific. According to other results no major induction of oxidative stress could be proven. Enhancement of antioxidant status with vitamin E in the case of DON and T-2 toxin intoxication can be beneficial for remaining the lymphocyte DNA integrity.     

Mycotoxins in cereal grain (part 15). Distribution of deoxynivalenol in naturally contaminated wheat kernels

The analysis of deoxynivalenol (DON) in naturally infected wheat samples, after having been separated into four fractions through laboratory sieves, showed very low levels of DON in the fraction of largest kernels >2.8 mm (0 up to 1 mg/kg). The highest concentration of DON was found in fractions 2.2 to 2.5 mm and <2.2mm with up to 14mg/kg and 15mg/kg DON, respectively. In two samples (fractions <2.2mm) nivalenol was detected in concentrations up to 1,4mg/kg.     

Evaluation of corn germplasm lines for multiple ear-colonizing insect and disease resistance

Ear-colonizing insects and diseases that reduce yield and impose health threats by mycotoxin contaminations in the grain, are critical impediments for corn (Zea mays L.) production in the southern United States. Ten germplasm lines from the Germplasm Enhancement of Maize (GEM) Program in Ames, IA, and Raleigh, NC, and 10 lines (derived from GEM germplasm) from the Texas Agricultural Experiment Station in Lubbock, TX, were examined in 2007 and 2008 with local resistant and susceptible controls. Four types of insect damage and smut disease (Ustilago maydis) infection, as well as gene X environment (G X E) interaction, was assessed on corn ears under field conditions. Insect damage on corn ears was further separated as cob and kernel damage. Cob penetration rating was used to assess corn earworm [Helicoverpa zea (Boddie)] and fall armyworm [Spodoptera frugiperda (J.E. Smith)] feeding on corn cobs, whereas kernel damage was assessed using three parameters: 1) percentage of kernels discolored by stink bugs (i.e., brown stink bug [Euschistus serous (Say)], southern green stink bug [Nezara viridula (L.)], and green stink bug [Chinavia (Acrosternum) hilare (Say)]; 2) percentage of maize weevil (Sitophilus zeamais Motschulsky)-damaged kernels; and 3) percentage of kernels damaged by sap beetle (Carpophilus spp.), "chocolate milkworm" (Moodna spp.), and pink scavenger caterpillar [Pyroderces (Anatrachyntis) rileyi (Walsingham)]. The smut infection rates on ears, tassels, and nodes also were assessed. Ear protection traits (i.e., husk tightness and extension) in relation to insect damage and smut infection also were examined. Significant differences in insect damage, smut infection, and husk protection traits were detected among the germplasm lines. Three of the 20 germplasm lines were identified as being multiple insect and smut resistant. Of the three lines, entries 5 and 7 were derived from DKXL370, which was developed using corn germplasm from Brazil, whereas entry 14 was derived from CUBA117.     

Survey and risk assessment of the mycotoxins deoxynivalenol,zearalenone, fumonisins,ochratoxin A,and aflatoxins in commercial dry dog food

The aim of the present study was to investigate the occurrence of mycotoxins in commercial dog food, as a basis to estimate the risk of adverse effects. Seventy-six dry dog food samples from 27 producers were purchased from retail shops, supermarkets, and specialized pet food shops in Vienna, Austria. The frequency and levels of deoxynivalenol (DON), zearalenone (ZEA), fumonisins (FUM), ochratoxin A (OTA). and aflatoxins (AF) in dry dog food were determined. Mycotoxin analysis were performed by commercial enzyme-linked immunosorbent assay (ELISA) test kits. Confirmatory analyses were done for DON, ZEA, and FUM by high performance liquid chromatography (HPLC) after extract clean-up with immunoaffinity columns. The correlations between ELISA and HPLC results for DON and ZEA were acceptable and indicated that ELISA could be a simple, low cost, and sensitive screening tool for mycotoxins detection, contributing to quality and safety of pet food. DON was the mycotoxin most frequently found (83% positives; median 308 μg/kg, maximum 1,390 μg/kg). ZEA (47% positives, median 51 μg/kg and maximum 298 μg/kg) and FUM (42% positives, median 122 μg/kg and maximum 568 μg/kg) were also frequently detected in dog food. OTA was less frequently found (5%, median 3.6 μg/kg, maximum 4.7 μg/kg. AF were not detected (<0.5 μg/kg) in any sample. The results show that dry dog food marketed in Vienna are frequently contaminated with mycotoxins (DON > ZEA > FUM > OTA) in low concentrations, but do not contain AF. The high frequency of Fusarium toxins DON, ZEA, and FUM indicates the need for intensive control measures to prevent mycotoxins in dog foods. The mycotoxin levels found in dry dog food are considered as safe in aspects of acute mycotoxicoses. However, repeated and long-time exposure of dogs to low levels of mycotoxins may pose a health risk.     

FUM1--a gene required for fumonisin biosynthesis but not for maize ear rot and ear infection by Gibberella moniliformis in field tests

We have analyzed the role of fumonisins in infection of maize (Zea mays) by Gibberella moniliformis (anamorph Fusarium verticillioides) in field tests in Illinois and Iowa, United States. Fumonisin-nonproducing mutants were obtained by disrupting FUM1 (previously FUM5), the gene encoding a polyketide synthase required for fumonisin biosynthesis. Maize ear rot, ear infection, and fumonisin contamination were assessed by silk-channel injection in 1999 and 2000 and also by spray application onto maize silks, injection into maize stalks, and application with maize seeds at planting in 1999. Ear rot was evaluated by visual assessment of whole ears and by calculating percentage of symptomatic kernels by weight. Fumonisin levels in kernels were determined by high-performance liquid chromatography. The presence of applied strains in kernels was determined by analysis of recovered isolates for genetic markers and fumonisin production. Two independent fumonisin-nonproducing (fum1-3 and fum1-4) mutants were similar to their respective fumonisin-producing (FUM1-1) progenitor strains in ability to cause ear rot following silk-channel injection and also were similar in ability to infect maize ears following application by all four methods tested. This evidence confirms that fumonisins are not required for G. moniliformis to cause maize ear rot and ear infection.     

Characterisation of<Emphasis Type="Italic">fusarium graminearum</Emphasis> and<Emphasis Type="Italic">F. culmorum</Emphasis> isolates by mycotoxin production and aggressiveness to wheat

A total of 27Fusarium culmorum isolates from Germany and 41F. graminearum isolates from Kenya were investigated for aggressiveness and mycotoxin production on wheat ears. In addition, ergosterol content of the kernels from ears inoculated withF. graminearum was determined and theF. culmorum isolates were tested for mycotoxin productionin vitro. For both pathogens, isolates markedly differed in aggressiveness. 59% and 37% of theF. culmorum isolates produced NIV and DON, respectively,in vivo andin vitro. The DON-producing isolates also produced 3-acDONin vitro. The more aggressive isolates produced mainly DON while the less aggressive isolates produced mainly NIV. 12% and 85% of theF. graminearum isolates produced NIV and DON, respectively. The highly aggressive isolates produced higher amounts of DON, aggressiveness being highly correlated to DON content in the kernels. NIV-producing isolates were less aggressive. Ergosterol content of kernels was moderately correlated to aggressiveness but highly correlated to DON content. Disease severity was associated with kernel weight reduction.     

Mycotoxins in foods in Lower Saxony (Germany): results of official control analyses performed in 2009

In this presentation, the mycotoxin levels—as analysed by the analytical centre for mycotoxin surveillance of the state food laboratory (LAVES Braunschweig)—for approximately 500 food samples are reported. The samples were collected in the year 2009 at retail in the German federal state of Lower Saxony. Aflatoxin and ochratoxin A were analysed in dried fruits, spices, cereals and tree nuts. Ochratoxin A was detected in all samples of dried vine fruits, at levels up to 8.1 μg/kg. Aflatoxins and ochratoxin A were also found in nutmeg and curry powder: the maximum regulatory levels for aflatoxins were exceeded in 25% of the nutmeg samples. Nearly all samples of basmati rice contained aflatoxins, although at levels below the maximum regulatory level in all but one sample. Aflatoxins were also detected in about 50% of hazelnut samples, in 20% of the samples the maximum levels was exceeded (maximum 23.2 μg/kg). In contrast, aflatoxin contents in pistachios were surprisingly low. Fusarium toxins were analysed in cereals and cereal products such as flour, bread, and pasta. Deoxynivalenol (DON) was the predominant toxin found in these samples: DON was found in about 40% of the samples, although the maximum levels were not exceeded (max. 418 μg/kg). Fumonisins (FBs) and zearalenone (ZEA) were specifically analysed in maize products (snacks, flour and oil). Most of these samples (80%) were positive, but at levels not exceeding the maximum levels. Maximum levels were 98 μg/kg (ZEA) and 577 μg/kg (sum of FB₁ and FB₂). Ergot alkaloids (six major alkaloids) were analysed in rye flour, and approximately 50% were positive. The highest concentration of ergot alkaloids was 1,063 μg/kg; the predominant alkaloids were ergotamine and ergocristine. In conclusion, the results indicate that continuous and efficient control measures for mycotoxins in a wide range of critical foods are necessary to ensure compliance with maximum levels. Although the mycotoxin levels in the vast majority of samples were below maximum levels, year-to-year variation and changes in the production of relevant commodities may result in a different picture in the future.     

A review on comparative data concerning <Emphasis Type="Italic">Fusarium</Emphasis> mycotoxins in Bt maize and non-Bt isogenic maize

The European corn borer reportedly promotes the infection of maize by Fusarium spp. Stalk and ear rots caused by Fusarium spp. are often related to mycotoxin accumulation in maize kernels. As a result, food and animal feed from maize are more severely contaminated with Fusarium mycotoxins: e.g. fumonisins (FUM), deoxynivalenol (DON) and zearalenone (ZEA). Bt maize is primarily an important potential tool for insect pest protection, both in the European Union and in other countries. Bt maize carrying the Bt genes is highly resistant to European corn borer larval feeding due to Bt toxin (δ toxin) production. Effective measures to combat pests therefore often have a positive side-effect in that they also reduce mycotoxin levels. Comparative analysis was used to the evaluation of the studies dealing with the reduction of Fusarium mycotoxins in Bt maize. Nineteen out of 23 studies on Bt maize came to the conclusion that Bt maize is less contaminated with mycotoxins (FUM, DON, ZEA) than the conventional control variety in each case.     

Mycotoxins in horse feed

A total of 62 samples of commercial horse feed preparations (complementary feeds) containing cereal mixtures (“muesli” or mash, n = 39; pelleted feeds, n = 12), and plain horse feed grains (maize, n = 5; oats, n = 4; barley, n = 2) were purchased from 21 different producers/distributors from the German market. All samples were analysed by competitive enzyme immunoassays (EIA) for six different mycotoxins (mycotoxin groups). Analytes (detection limit, mean recovery) were: deoxynivalenol (DON, 10 μg/kg, 84%), zearalenone (ZEA, 5 μg/kg, 93%), fumonisin B₁ (FB₁, 2 μg/kg, 113%), T-2 toxin (T-2, 0.1 μg/kg, 71%), sum of T-2 + HT-2 toxin (T-2/HT2, 0.2 μg/kg, 97%), ochratoxin A (OTA, 0.2 μg/kg, 67%), and total ergot alkaloids (Generic Ergot Alkaloids “GEA”, 30 μg/kg, 132%). All samples contained DON (16–4,900 μg/kg, median 220 μg/kg), T-2/HT-2 (0.8–230 μg/kg, median 24 μg/kg), and T-2 (0.3–91 μg/kg, median 7 μg/kg). ZEA was detected in 98% of the samples (7–310 μg/kg, median 61 μg/kg). Most samples (94%) were positive for FB₁ (2–2,200 μg/kg, median 27 μg/kg). Ergot alkaloids were detected in 61% of samples (28–1,200 μg/kg, median 97 μg/kg), OTA was found in 42% of samples (0.2–4 μg/kg, median 0.35 μg/kg). The results demonstrate that a co-contamination with several mycotoxins is very common in commercial horse feed from the German market. The toxin concentrations were in most cases well below the levels which are usually considered as critical or even toxic. The highest mycotoxin concentrations were mostly found in single-grain cereal feed: the maximum values for DON and FB₁ were found in maize, the highest T-2/HT-2 toxin concentrations were found in oats, and the highest concentration of ergot alkaloids was found in barley. In composed feeds, no correlation between cereal composition and mycotoxin levels could be found.