Mycotoxin Research

Die Maus-Thymoma-Zellinie EL-4 diente alsin-vitro-T-Zell-Modell für Untersuchungen immunmodulatorischer Effekte von reinem Ochratoxin A (OTA) sowie von einerAspergillus-ochraceaus-Rohtoxinpräparation. Die Zytokinproduktion (IL-2, IL-4, IL-5, IL-6) und die Vitalität PMA-stimulierter EL-4-Zellen wurde unter OTA-Einwirkung untersucht. Rohtoxin wirkte im Vergleich zum reinen OTA bereits bei niedrigeren OTA-Konzentrationen zytotoxisch (IC50-Werte 3 bzw. 11 µg/ml). Steigende Konzentrationen von beiden OTA-Präparationen führten zur Hemmung der Zytokin-Ausschüttung, wobei Rohtoxin wiederum stärker wirkte. Dies deutet auf den Einfluß weiterer noch nicht näher charakterisierter Bestandteile des Rohtoxins hin. Die unterschiedlichen Hemmkonzentrationen von OTA gegenüber den einzelnen Zytokinen machen deutlich, daß auch eine unterschiedliche Empfindlichkeit der betreffenden Regulations-Mechanismen vorliegen könnte. Bei bestimmten Konzentrationen waren bei IL-2 und IL-6 auch stimulierende Effekte beider Toxin-Präparationenen nachweisbar, wogegen diese Konzentrationen bei IL-4 und IL-5 bereits hemmten.

The lethality of T-2 toxin to adult femaleAedes aegypti mosquitoes was investigated using various methods of application: Topically, by injection, and by natural feeding. The technique of topical application was found to be the most precise, whereby an LD50 of 565 ng T-2 toxin/mosquito was determined.

Breakfast processed products are remarkably at risk of fungal contamination. This research surveyed the fumonisins concentration in different breakfast products and carried out in vitro experiments measuring fumonisins content in different substrates inoculated with Fusarium verticillioides. The pipeline started with the identification of combinations of ingredients for 58 breakfast products. Twenty-three core ingredients, seven nutritional components and production types were analyzed using a Pearson correlation, k-means clustering, and principal component analysis to show that no single factor is responsible for high fumonisins detection in processed cereals products. Consequently, decision tree regression was used as a means of determining and visualizing complex logical interactions between the same factors. We clustered the association of ingredients in low, medium, and high risk of fumonisin detection. The analysis showed that high fumonisins concentration is associated with those products that have high maize concentrations coupled especially with high sodium or rice. In an in vitro experiment, different media were prepared by mixing the ingredients in the proportion found in the first survey and by measuring fumonisins production by Fusarium verticillioides. Results showed that (1) fumonisins production by F. verticillioides is boosted by the synergistic effect of maize and highly ready carbohydrate content such as white flour; (2) a combination of maize > 26% (w/w), rice > 2.5% (w/w), and NaCl > 2.2% (w/w) led to high fumonisins production, while mono-ingredient products were more protective against fumonisins production. The observations in the in vitro experiments appeared to align with the decision tree model that an increase in ingredient complexity can lead to fumonisins production by Fusarium. However, more research is urgently needed to develop the area of predictive mycology based on the association of processing, ingredients, fungal development, and mycotoxins production.

A study was conducted to determine the distribution of deoxynivalenol (DON) and ochratoxin A (OTA) in a lot of 261 of wheat kernels. Within this study, two different sampling and sample preparation strategies were carried out. On the one hand, following the official commission regulation 401/2006/EC, an aggregate sample out of 100 incremental samples was build, homogenized and prepared for laboratory analysis. On the other hand each individual subsample was investigated for its deoxynivalenol and ochratoxin A content. The determined concentration of DON in the individual samples was in a range from 830 up to 2655 (μg/kg, for OTA results ranged from < 0.2 up to 8.6 μg/kg. Thus, a coefficient of variance of 25% for DON and 200% for OTA was achieved. From this, a spot formation for OTA was observed and the average value of the 100 incremental samples did not correspond to the achieved value for the aggregate sample. While the DON contamination at this concentration range seems to be more even, consequently the result of the aggregate sample was in accordance with the average value. In addition a sample communition study was performed to answer the question whether the time consuming process of grinding of the whole aggregate sample is necessary or not. The results of this study show that contamination of whole wheat kernels with DON is at the same level within a 1 kg sample (CV 16%), while OTA contamination shows high variability (CV 94%). At least for OTA this study indicated that an extensive and complete sample communition of the high volume aggregate sample is necessary.

New information is needed regarding the types and concentrations of mycotoxins in swine feed. We hypothesized that (1) the mycotoxins deoxynivalenol (DON), 3-acetyldeoxynivalenol (3-AcDON), 15-acetyldeoxynivalenol (15-AcDON), nivalenol (NIV), and zearalenone (ZEN) vary among swine ingredient and feed types, and (2) the inclusion of specific ingredients is associated with mycotoxin contamination in complete feed. A total of 707 samples were collected from cooperators in 14 states between June 2018 and January 2020 then analyzed for DON, 3-AcDON, 15-AcDON, NIV, and ZEN contamination using gas chromatography–mass spectrometry (GC–MS). Ninety-four percent (663/707) of samples contained DON, 33% (230/707) of samples contained 3-AcDON, 57% (404/707) of samples contained 15-AcDON, 1% (6/707) of samples contained NIV, and 47% (335/707) of samples contained ZEN. Seventy-three percent (514/707) of samples contained multiple mycotoxins. Resulting DON concentrations were below the national advisory limits for all sample types, and no advisory limits are imposed for the other mycotoxins studied. Increased incorporation of distiller’s dried grains with solubles (DDGS) was associated with increased DON in complete feed (R2 = 0.82).

This work deals with the characterisation of trichothecene metabolites after the microbial degradation by the bacterial strain BBSH 797. Besides deoxynivalenol (DON), also the degradation of other trichothecenes was investigated. In the case of nivalenol, its metabolite deepoxy nivalenol could be identified. Useful methods for the structural characterisation are GC-MS or LC-PB-MS which were used in this particular case.

T-2 toxin, a toxic member of the group A trichothecenes, is produced by various Fusarium species that can potentially affect human health. As the intestine plays an important role in the metabolism of T-2 toxin for animals and humans, the degradation and metabolism of T-2 toxin was studied using the pig cecum in vitro model system developed in the author’s group. In order to study the intestinal degradation of T-2 toxin by pig microbiota, incubation was performed with the cecal chyme from four different pigs in repeat determinations. A large variation in the intestinal degradation of T-2 toxin was observed for individual pigs. T-2 toxin was degraded almost completely in one out of four pigs, in which only 3.0 ± 0.1 % of T-2 toxin was left after 24 h incubation. However, in the other three incubations with pig cecal suspension, 54.1 ± 11.7–68.9 ± 16.1 % of T-2 toxin were still detectable after 24 h incubation time. The amount of HT-2 toxin was increased along with the incubation time, and HT-2 toxin accounted for 85.2 ± 0.7 % after 24 h in the most active cecum. HT-2 toxin was the only detectable metabolite formed by the intestinal bacteria. This study suggests that the toxicity of T-2 toxin for pigs is caused by the combination of T-2 and HT-2 toxins.

Standard dialysis did not result in a decrease of the OTA level in the blood serum of patients regularly treated by dialysis. Therefore, we examined the effect of dialysis on both OTA bound to the blood plasma proteins and free OTA. We carried out an in vivo experiment to determine OTA levels in the serum of patients in the terminal stage of chronic renal insufficiency (CHRI) before and after dialysis and also in the dialysate in which we did not find OTA. OTA bound to blood plasma proteins did not penetrate the dialysis membrane. In contrast, free OTA during an in vitro experiment with the identical dialyzer (as during the in vivo experiment), easily penetrated the same dialysis membrane.