Occurrence of type A, B and D trichothecenes, zearalenone and stachybotrylactam in straw.

Straw is the main by-product of grain production, used as bedding material and animal feed. If produced or stored under adverse hygienic conditions, straw is prone to the growth of filamentous fungi. Some of them, e.g. Aspergillus, Fusarium and Stachybotrys spp. are well-known mycotoxin producers. Since studies on mycotoxins in straw are scarce, 192 straw samples (wheat n = 80; barley n = 79; triticale n = 12; oat n = 11; rye n = 12) were collected across Germany within the German official feed surveillance and screened for the presence of 21 mycotoxins. The following mycotoxins (positive samples for at least one mycotoxin n = 184) were detected: zearalenone (n = 86, 6.0-785 µg/kg), nivalenol (n = 51, 30-2,600 µg/kg), deoxynivalenol (n = 156, 20-24,000 µg/kg), 15-acetyl-deoxynivalenol (n = 34, 20-2,400 µg/kg), 3-acetyl-deoxynivalenol (n = 16, 40-340 µg/kg), scirpentriol (n = 14, 40-680 µg/kg), T-2 toxin (n = 67, 10-250 µg/kg), HT-2 toxin (n = 92, 20-800 µg/kg), T-2 tetraol (n = 13, 70-480 µg/kg). 15-monoacetoxyscirpenol (30 µg/kg) and T-2 triol (60 µg/kg) were only detected in one barley sample. Macrocyclic trichothecenes (satratoxin G, F, roridin E, and verrucarin J) were also found in only one barley sample (quantified as roridin A equivalent: total 183 µg/kg). The occurrence of stachybotrylactam was monitored for the first time in four samples (n = 4, 0.96-7.4 µg/kg). Fusarenon-X, 4,15-diacetoxyscirpenol, neosolaniol, satratoxin H and roridin-L2 were not detectable in the samples. The results indicate a non-negligible contribution of straw to oral and possibly inhalation exposure to mycotoxins of animals or humans handling contaminated straw.

The NADPH Oxidase and the Phagosome.

The key purpose of phagocytosis is the destruction of pathogenic microorganisms. The phagocytes exert a wide array of killing mechanisms that allow mastering the vast majority of pathogens. One of these mechanisms consists in the production of reactive oxygen species inside the phagosome by a specific enzyme, the phagocyte NADPH oxidase. This enzyme is composed of 6 proteins that need to assemble to form a complex on the phagosomal membrane. Multiple signaling pathways tightly regulate the assembly. We briefly summarize key features of the enzyme and its regulation. We then focus on several related topics that address the activity of the NADPH oxidase during phagocytosis. Novel fluorescence microscopy techniques combined with fluorescent protein labeling of NADPH oxidase subunits opened the view on the structure and dynamics of these proteins in living cells. This combination revealed details of the role of anionic phospholipids in the control of phagosomal ROS production. It also added critical information to propose a 3D model of the complex between the cytosolic subunits prior to activation, in complement to other structural data on the oxidase.

Haematological and immunological adaptations of non-pregnant, non-lactating dairy cows to a high-energetic diet containing mycotoxins.

Diet change and fatness are supposed to challenge the immune system of the cow. Therefore, immunological and haematological consequences of adaptation to and continued feeding of a high-energy diet were studied in eight non-pregnant, non-lactating Holstein cows over 16 weeks. Blood haptoglobin concentration remained unaltered, suggesting that an acute phase reaction was not induced. Stimulation ability of peripheral blood mononuclear cells and stimulated oxidative burst capacity of granulocytes increased significantly in the course of the experiment after an initial drop. While total leucocyte counts increased, the proportion of granulocytes increased and that of lymphocytes decreased at the same time as the ratio of CD4(+)/CD8(+) lymphocytes did. Capability of rumen microbes to detoxify the immune-modulating mycotoxin deoxynivalenol (DON) was not compromised as indicated by the exclusive presence of de-DON as the detoxified DON metabolite in blood. In conclusion, both diet change and prolonged positive energy balance influenced the bovine immune system.

Residues of deoxynivalenol (DON) and its metabolite de-epoxy-DON in eggs, plasma and bile of laying hens of different genetic backgrounds.

In the present study, the potential for carry-over of deoxynivalenol (DON) into eggs and DON residues in plasma and bile of laying hens of different genetic backgrounds after long-term feeding trial was investigated. A total of 80, 23-week-old laying hens were assigned to a feeding trial with two diets, a control diet and a Fusarium toxin-contaminated diet (FUS) (0.4 and 9.9 mg DON kg(-1), respectively). In the 60th week of hen's life, 10 eggs from each group were collected. In the 70th week of hen's life, all hens were slaughtered and samples of blood and bile were collected. The samples were analysed by liquid chromatography tandem mass spectrometry (LC-MS/MS) for DON and de-epoxy-DON. DON was only detected in samples of hens which fed the FUS diet while none of the samples analysed had detectable levels of de-epoxy-DON. In plasma and bile samples, DON levels ranged from 0.2 to 0.6 ng ml(-1) and from 1.8 to 4.1 ng ml(-1), respectively. DON levels in egg yolk and albumen ranged between 0.0-0.46 ng g(-1) and 0.0-0.35 ng g(-1), respectively, corresponding to carry-over rates of DON into eggs from 0.0 to 0.000016. Moreover, no differences in DON levels or carry-over rates were noticed between the two tested breeds. These results show that very low levels of DON were transferred into eggs and indicate that although eggs could contribute to human exposure to DON, the levels are very low and insignificant.

Diagnosis of intoxications of piglets fed with Fusarium toxin-contaminated maize by the analysis of mycotoxin residues in serum, liquor and urine with LC-MS/MS.

Concentrations of zearalenone (ZEN), deoxynivalenol (DON) and their metabolites α-zearalenol (α-ZEL), ß-zearalenol (ß-ZEL), zearalanone (ZAN), α-zearalanol (α-ZAL), ß-zearalanol (ß-ZAL) and de-epoxy-deoxynivalenol (de-DON) in serum, liquor and urine of female piglets fed diets containing 0.01, 0.05, 0.08, 0.17 and 0.29 mg ZEN/kg and 0.03, 0.59, 1.27, 2.01 and 4.52 mg DON/kg during 29 days of treatment were analysed. After 1, 3, 8, 15, 22 and 29 days, four piglets per group were slaughtered. The simultaneous determination of all analytes was carried out using a sensitive and selective in-house-validated liquid chromatography tandem mass spectrometry (LC-MS/MS) method after sample preparation with Oasis™ HLB columns. ZEN, α-ZEL, DON and de-DON were detected in serum, whereas in liquor only ZEN, DON and de-DON were found at lower concentrations. In urine, all analytes were detected in considerably higher concentrations as in serum and liquor, whereby α- and ß-ZAL could only be detected sporadically. Apart from ZEN in liquor and α- and ß-ZAL in urine, the mycotoxin concentrations increased with increasing concentrations of Fusarium toxins in the diet. The toxin intake per kg body weight 3-4 h prior to slaughtering correlated well with the DON and the sum of DON and de-DON concentrations in all three specimens as well as with the ZEN, α-ZEL and the sum of ZEN and metabolite concentrations in urine. Due to the high correlation between the dietary DON concentration and the DON (r = 0.855) and the sum of DON and de-DON (r = 0.870) concentration in serum, the exposure to DON can be evaluated. Moreover, serum levels of these toxins indicative of an exceeding of the guidance value in feed can be established using the corresponding regression equations. Strictly speaking, these relationships are only valid for the experimental conditions of the underlying experiment. For practical application of these relationships, the individual variation needs to be additionally considered. Effects of the duration of toxin exposure within the feeding groups were observed for ZEN, DON and de-DON in all specimens as well as for α-ZEL, ß-ZEL and ZAN in urine.

Per-pixel unmixing of spectrally overlapping fluorophores using intra-exposure excitation modulation.

Multilabel fluorescence imaging is essential for the visualization of complex systems, though a major challenge is the limited width of the useable spectral window. Here, we present a new method, exNEEMO, that enables per-pixel quantification of spectrally-overlapping fluorophores based on their light-induced dynamics, in a way that is compatible with a very broad range of timescales over which these dynamics may occur. Our approach makes use of intra-exposure modulation of the excitation light to distinguish the different emitters given their reference responses to this modulation. We use the approach to simultaneously image four green photochromic fluorescent proteins at the full spatial resolution of the imaging.

Latest trends in bioimaging and building a proactive network of early-career young scientists around bioimaging in Europe.

Biological research is in constant need of new methodological developments to assess organization and functions at various scales ranging from whole organisms to interactions between proteins. One of the main ways to evidence and quantify biological phenomena is imaging. Fluorescence microscopy and label-free microscopy are in particular highly active fields of research due to their compatibility with living samples as well as their versatility. The Imabio Young Scientists Network (YSN) is a group of young scientists (PhD students, postdocs and engineers) who are excited about bioimaging and aim to create a proactive network of researchers with the same interest. YSN is endorsed by the bioimaging network GDR Imabio in France, where the initiative was started in 2019. Since then, we aim to organize the Imabio YSN conference every year to expand the network to other European countries, establish new collaborations and ignite new scientific ideas. From 6-8 July 2022, the YSN including researchers from the domains of life sciences, chemistry, physics and computational sciences met at the Third Imabio YSN Conference 2022 in Lyon to discuss the latest bioimaging technologies and biological discoveries. In this Meeting Review, we describe the essence of the scientific debates, highlight remarkable talks, and focus on the Career Development session, which is unique to the YSN conference, providing a career perspective to young scientists and help to answer all their questions at this career stage. This conference was a truly interdisciplinary reunion of scientists who are eager to push the frontiers of bioimaging in order to understand the complexity of biological systems.

Consequences of the constitutive NOX2 activity in living cells: Cytosol acidification, apoptosis, and localized lipid peroxidation.

The phagocyte NADPH oxidase (NOX2) is a key enzyme of the innate immune system generating superoxide anions (O2•-), precursors of reactive oxygen species. The NOX2 protein complex is composed of six subunits: two membrane proteins (gp91phox and p22phox) forming the catalytic core, three cytosolic proteins (p67phox, p47phox and p40phox) and a small GTPase Rac. The sophisticated activation mechanism of the NADPH oxidase relies on the assembly of cytosolic subunits with the membrane-bound components. A chimeric protein, called 'Trimera', composed of the essential domains of the cytosolic proteins p47phox (aa 1-286), p67phox (aa 1-212) and full-length Rac1Q61L, enables a constitutive and robust NOX2 activity in cells without the need of any stimulus. We employed Trimera as a single activating protein of the phagocyte NADPH oxidase in living cells and examined the consequences on the cell physiology of this continuous and long-term NOX activity. We showed that the sustained high level of NOX activity causes acidification of the intracellular pH, triggers apoptosis and leads to local peroxidation of lipids in the membrane. These local damages to the membrane correlate with the strong tendency of the Trimera to clusterize in the plasma membrane observed by FRET-FLIM microscopy.

Emerging applications of nanobodies in cancer therapy.

Cancer is a heterogeneous disease, requiring treatment tailored to the unique phenotype of the patient's tumor. Monoclonal antibodies (mAbs) and variants thereof have enabled targeted therapies to selectively target cancer cells. Cancer cell-specific mAbs have been used for image-guided surgery and targeted delivery of radionuclides or toxic agents, improving classical treatment strategies. Cancer cell-specific mAbs can further inhibit tumor cell growth or can stimulate immune-mediated destruction of cancer cells, a feature that has also been achieved through mAb-mediated manipulation of immune cells and pathways. Drawbacks of mAbs and their variants, together with the discovery of camelid heavy chain-only antibodies and the many advantageous features of their variable domains, referred to as VHHs, single domain antibodies or nanobodies (Nbs), resulted in the exploration of Nbs as an alternative targeting moiety. We therefore review the state-of-the-art as well as novel exploitation strategies of Nbs for targeted cancer therapy.

Separation of spectrally overlapping fluorophores using intra-exposure excitation modulation.

Multicolor fluorescence imaging is an excellent method for the simultaneous visualization of multiple structures, although it is limited by the available spectral window. More labels can be measured by distinguishing these on properties, such as their fluorescence dynamics, but usually these dynamics must be directly resolvable by the instrument. We propose an approach to distinguish emitters over a much broader range of light-induced dynamics by combining fast modulation of the light source with the detection of the time-integrated fluorescence. We demonstrate our method by distinguishing four spectrally overlapping photochromic fluorophores within Escherichia coli bacteria, showing that we can accurately classify all four probes by acquiring just two to four fluorescence images. Our strategy expands the range of probes and processes that can be used for fluorescence multiplexing.

tdLanYFP, a Yellow, Bright, Photostable, and pH-Insensitive Fluorescent Protein for Live-Cell Imaging and Förster Resonance Energy Transfer-Based Sensing Strategies.

Yellow fluorescent proteins (YFPs) are widely used as optical reporters in Förster resonance energy transfer (FRET)-based biosensors. Although great improvements have been done, the sensitivity of the biosensors is still limited by the low photostability and the poor fluorescence performances of YFPs at acidic pH values. Here, we characterize the yellow fluorescent protein tdLanYFP, derived from the tetrameric protein from the cephalochordate Branchiostoma lanceolatum, LanYFP. With a quantum yield of 0.92 and an extinction coefficient of 133,000 mol-1·L·cm-1, it is, to our knowledge, the brightest dimeric fluorescent protein available. Contrasting with EYFP and its derivatives, tdLanYFP has a very high photostability in vitro and in live cells. As a consequence, tdLanYFP allows imaging of cellular structures with subdiffraction resolution using STED nanoscopy and is compatible with the use of spectromicroscopies in single-molecule regimes. Its very low pK1/2 of 3.9 makes tdLanYFP an excellent tag even at acidic pH values. Finally, we show that tdLanYFP is a valuable FRET partner either as a donor or acceptor in different biosensing modalities. Altogether, these assets make tdLanYFP a very attractive yellow fluorescent protein for long-term or single-molecule live-cell imaging including FRET experiments at acidic pH.

Plasma kinetics and matrix residues of deoxynivalenol (DON) and zearalenone (ZEN) are altered in endotoxaemic pigs independent of LPS entry site.

This study aimed to investigate a potential modulatory effect of E. coli lipopolysaccharide (LPS) on the kinetics of deoxynivalenol (DON) and zearalenone (ZEN) after pre- or post-hepatic LPS administration to unravel the putative role of the liver. Fifteen barrows were fed a diet containing mycotoxin-contaminated maize (4.59 mg DON/kg feed, 0.22 mg ZEN/kg feed) for 29 days and equipped with pre-hepatic catheters (portal vein, "po") and post-hepatic catheters (jugular vein, "ju"), facilitating simultaneous infusion of LPS ("LPS group", 7.5 µg/kg body weight) or 0.9% sterile NaCl solution (control, "CON group", equivolumar to LPS group) and blood sampling. This resulted in three infusion groups, depending on infusion site: CONju-CONpo, CONju-LPSpo, and LPSju-CONpo. On day 29, pigs were fed their morning ration (700 g/pig) (-15 min), and blood samples were collected at regular intervals relative to infusion start. At 195 min, pigs were sacrificed and bile, urine, liquor, and liver samples collected. DON concentrations in jugular and portal blood decreased in both LPS-infused groups, whereas the ZEN concentrations increased, regardless of the treatment site. In liver tissue, a decrease of both toxin concentrations was observed in endotoxaemic pigs as well as a drop in hepatic conjugation, regardless of LPS entry site. In contrast to our hypothesis, DON and ZEN were not differently altered depending on the LPS-entry site. Neither the absorption nor the accumulation of DON and ZEN in different tissues differed significantly between animals which were infused with LPS via either the jugular or portal vein.

Determination of T-2 toxin, HT-2 toxin, and three other type A trichothecenes in layer feed by high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS)--comparison of two sample preparation methods.

A sensitive method for the simultaneous determination of T-2 toxin, HT-2 toxin, neosolaniol, T-2 triol, and T-2 tetraol in layer feed using high-performance liquid chromatography coupled to triple quadrupole mass spectrometry in the positive ionization mode (LC-ESI-MS/MS) is described. Two fast and easy clean-up methods-with BondElut Mycotoxin and MycoSep 227 columns, respectively-were tested. The separation of the toxins was conducted on a Pursuit XRs Ultra 2.8 HPLC column using 0.13 mM ammonium acetate as eluent A and methanol as eluent B. Detection of the mycotoxins was carried out in the multiple reaction monitoring (MRM) mode using ammonium adducts as precursor ions. Quantification of all analytes was performed with d3-T-2 toxin as an internal standard. The clean-up method with MycoSep 227 columns gave slightly better results for layer feed compared to the method using BondElut Mycotoxin columns (MycoSep 227: recovery between 50 and 63%, BondElut Mycotoxin: recovery between 32 and 67%) and was therefore chosen as the final method. The limits of detection ranged between 0.9 and 7.5 ng/g depending on the mycotoxin. The method was developed for the analysis of layer feed used at carry-over experiments with T-2 toxin in laying hens. For carry-over experiments, it is necessary that the method includes not only T-2 toxin but also the potential metabolites in animal tissues HT-2 toxin, neosolaniol, T-2 triol, and T-2 tetraol which could naturally occur in cereals used as feed stuff as well.

Study on the transmission of deoxynivalenol and de-epoxy-deoxynivalenol into eggs of laying hens using a high-performance liquid chromatography-ultraviolet method with clean-up by immunoaffinity columns.

The transmission of deoxynivalenol (DON) and of its metabolite de-epoxy-DON into eggs has not been sufficiently elucidated until now. This question was addressed within the scope of a 16-week experiment with laying hens which were fed a maize-based diet with a DON concentration of 11.9 mg x kg(-1 )dry matter. Eggs were collected during weeks 2, 4, 8, and 16 of the experiment, and DON and its metabolite de-epoxy-DON were analyzed in freeze-dried yolk and albumen. In order to cover possible conjugates, all samples were incubated with beta-glucuronidase prior to extraction. Yolk and albumen were extracted with acetonitrile-water, and the extracts were purified with immunoaffinity columns (IACs) after a precleaning step. The toxins were determined by high-performance liquid chromatography (HPLC) with UV detection. The detection limits of both toxins were 5 and 8 microg x kg(-1) in freeze-dried yolk and albumen, respectively, corresponding to approximately 2.5 and 1 microg x kg(-1) in fresh samples. The recovery of DON and de-epoxy-DON in yolk was 80% and 78%, respectively, and in albumen 77 and 72%. Neither DON nor de-epoxy-DON or glucuronide conjugates of both substances could be detected in any of the samples. These results indicate that eggs do not contribute significantly to the dietary DON intake of humans.

On the effects of graded levels of Fusarium toxin contaminated wheat in diets for gilts on feed intake, growth performance and metabolism of deoxynivalenol and zearalenone.

A total of 36 gilts (103 +/- 6 kg) were divided into four groups and fed diets with increasing proportions of a Fusarium toxin contaminated wheat over a period of 35 days. The concentrations of the indicator toxins deoxynivalenol (DON) and zearalenone (ZON) which were analyzed by HPLC methods were 210 and 4, 3070 and 88, 6100 and 235 and 9570 and 358 mug.kg(-1) diet fed to groups 1-4 respectively. Feed was partially refused during the first 21 days of the experiment by groups 2, 3 and 4 where two, three and six out of nine gilts were affected. No signs of hyperestrogenism or uterotrophic effects were observed due to dietary treatments. Blood serum, urine, bile and liver were analyzed for residues of DON, ZON and their metabolites. DON and its de-epoxidized metabolite (de-epoxy-DON) were detected in all analyzed specimens and increased in a significantly linearly related fashion. Alpha-zearalenol (alpha-ZOL) and beta-ZOL could be detected besides the parent toxin ZON, but only in bile and urine. In conclusion, the impact of dietary treatments on the performance parameters was most pronounced in the highest exposed group. The maximum ratio between DON concentration in liver and diet was 0.0013, and suggests that a possible contamination of pig liver with DON is negligible and does not contribute significantly to human DON exposure.

Effects of Dietary Exposure to Zearalenone (ZEN) on Carp (Cyprinus carpio L.).

The mycotoxin zearalenone (ZEN) is frequently contaminating animal feeds including feed used in aquaculture. In the present study, the effects of dietary exposure to ZEN on carp (Cyprinus carpio L.) were investigated. ZEN at three different concentrations (low dose: 332 µg kg(-1), medium dose: 621 µg kg(-1) and high dose: 797 µg kg(-1) final feed, respectively) was administered to juvenile carp for four weeks. Additional groups received the mycotoxin for the same time period but were fed with the uncontaminated diet for two more weeks to examine the reversibility of the ZEN effects. No effects on growth were observed during the feeding trial, but effects on haematological parameters occurred. In addition, an influence on white blood cell counts was noted whereby granulocytes and monocytes were affected in fish treated with the medium and high dose ZEN diet. In muscle samples, marginal ZEN and α-zearalenol (α-ZEL) concentrations were detected. Furthermore, the genotoxic potential of ZEN was confirmed by analysing formation of micronuclei in erythrocytes. In contrast to previous reports on other fish species, estrogenic effects measured as vitellogenin concentrations in serum samples were not increased by dietary exposure to ZEN. This is probably due to the fact that ZEN is rapidly metabolized in carp.

Development of a multi-toxin method for investigating the carryover of zearalenone, deoxynivalenol and their metabolites into milk of dairy cows.

A dose-response study was carried out to examine the carryover of zearalenone (ZEN), deoxynivalenol (DON) and their metabolites into bovine milk. Therefore, a feeding trial with 30 dairy cows fed with three different levels of Fusarium (FUS) toxin-contaminated maize was performed. A control group (0.02 mg ZEN kg(-1) dry matter (DM) and 0.07 DON kg(-1) DM) was compared with two groups fed contaminated diets. The first diet contained 0.33 mg ZEN kg(-1) DM and 2.62 mg DON kg(-1) DM (group FUS-50) and the second diet contained 0.66 mg ZEN kg(-1) DM and 5.24 mg DON kg(-1) DM (group FUS-100). For milk sample analysis, a new cost-efficient sample preparation method was developed for the simultaneous determination of ZEN, DON and their metabolites. The method comprised the separation of the milk fat followed by an SPE clean-up on Oasis HLB and a LC-MS/MS measurement. The less toxic metabolite de-epoxy-DON had the highest detected concentration (5.6 ng ml(-1) milk) in the milk samples obtained from the feeding trial. Additionally, ZEN (up to 0.29 ng ml(-1)), α-zearalenol (up to 0.17 ng ml(-1)), ß-zearalenol (up to 0.95 ng ml(-1)) and DON (up to 2.5 ng ml(-1)) were detected in these samples. The milk toxin concentrations of cows fed the control diet were significantly lower compared with cows fed the contaminated diet. The calculated carryover rates ranged between 0 and 0.0075 for ZEN and metabolites and between 0 and 0.0017 for DON independent of exposure. It can be concluded that dietary toxin concentrations in the feed below or close to the current guidance values do not pose a risk for consumers due to negligible carryover rates.

Development of a liquid chromatography tandem mass spectrometry method for the simultaneous determination of zearalenone, deoxynivalenol and their metabolites in pig serum.

A sensitive and selective liquid chromatography tandem mass spectrometry method using negative electrospray ionisation (LC-ESI-MS/MS) was developed for the simultaneous determination of zearalenone (ZEN), deoxynivalenol (DON) and their metabolites α-zearalenol, ß-zearalenol, zearalanone, α-zearalanol, ß-zearalanol and de-epoxy-deoxynivalenol in pig serum. For method development, different sample preparation columns were tested for their suitability for extraction and clean up. Finally, preparation of serum samples was carried out using Oasis™ HLB solid-phase extraction (SPE) columns. The analyte concentrations were determined by the use of isotopically labelled internal standards (IS). The method was in-house validated for all analytes. Calibration graphs (0.3-480 ng/ml) were prepared and high degree of linearity was achieved (r ≥ 0.99). Results for method precision ranged between 2.7 and 21.5 % for inter-day and between 1.1 and 11.1 % for intra-day. The recoveries were in the range of 82-131 %. Limits of detection and quantification ranged 0.03-0.71 and 0.08-2.37 ng/ml, respectively. The method has been successfully used for quantitative determination of ZEN, DON and their metabolites in pig serum from a feeding trial with practically relevant ZEN and DON concentrations. This method is precise and reproducible and can be used as a multi-biomarker method to assess animal exposure to these mycotoxins and for diagnosis of intoxications.

Effects of feeding deoxynivalenol (DON)-contaminated wheat to laying hens and roosters of different genetic background on the reproductive performance and health of the newly hatched chicks.

A total of 216 23-week-old laying hens from two different genetic backgrounds (half of the birds were Lohmann brown [LB] and [LSL] hens, respectively) and 24 adult roosters were assigned to a feeding trial to study the effect of increasing concentrations of deoxynivalenol (DON) in the diet (0, 5, 10 mg/kg) on the reproductive performance of hens and roosters, and the health of the newly hatched chicks. Hatchability was adversely affected by the presence of DON in LB hens' diet, while the hatchability of the LSL chicks was significantly higher than LB chicks. An interaction effect between DON in the hens' diet and the breed was noticed on fertility, as the fertility was decreased in the eggs of LB hens receiving 10 mg/kg DON in their diet and increased in the eggs of LSL hens fed 10 mg/kg DON. Moreover, spleen relative weight was significantly decreased in the chicks hatched from eggs of hens fed contaminated diets, while gizzard relative weight was significantly decreased in LB chicks with 10 mg/kg DON in their diet compared with the control group. On the other hand, the chicks' haematology and organ histopathology were not affected by the dietary treatment. Additionally, the presence of DON in the roosters' diet had no effect on fertility (the percentage of fertile eggs of all laid eggs). Consequently, the current results indicate a negative impact of DON in LB hens' diet on fertility and hatchability, indicating that the breed of the hens seems to be an additional factor influencing the effect of DON on reproductive performance of the laying hens.

In vivo effects of deoxynivalenol (DON) on innate immune responses of carp (Cyprinus carpio L.).

Deoxynivalenol (DON) is one of the most important members of Fusarium toxins since it often can be found in relevant concentrations in animal feeds. The effects of this group of toxins on fish are mostly unknown. The present study shows results from a feeding trial with carp (Cyprinus carpio L.) using three different concentrations of DON (352µgkg(-1), 619µgkg(-1), and 953µgkg(-1) final feed, respectively) which are comparable to levels found in commercial fish feeds. Effects on growth and mass of fish were not observed during this 6weeks lasting experiment. Only marginal DON concentrations were found in muscle and plasma samples. Blood parameters were not influenced although smaller erythrocytes occurred in fish treated with 352µgkg(-1) DON. Analysis of antioxidative enzymes in erythrocytes showed increased superoxid dismutase and catalase activities in fish fed the low-dose feed. Immunosuppressive effects of DON were confirmed whereby cytotoxic effects on immune cells only partly explained the impairment of innate immune responses. Exact polarization of the immune system into pro-inflammatory or anti-inflammatory responses due to DON exposure should be clarified in further experiments, especially since the current results raise concern about impaired immune function in fish raised in aquaculture.