Diametral influence of deoxynivalenol (DON) and deepoxy-deoxynivalenol (DOM-1) on the growth of Campylobacter jejuni with consequences on the bacterial transcriptome.

BACKGROUND: Deoxynivalenol (DON) is a type B trichothecene mycotoxin that is commonly found in cereals and grains worldwide. The presence of this fungal secondary-metabolite raises public-health concerns at both the agriculture and food industry level. Recently, we have shown that DON has a negative impact on gut integrity, a feature also noticed for Campylobacter (C.) jejuni. We further demonstrated that DON increased the load of C. jejuni in the gut and inner organs. In contrast, feeding the less toxic DON metabolite deepoxy-deoxynivalenol (DOM-1) to broilers reduced the Campylobacter load in vivo. Consequently, it can be hypothesized that DON and DOM-1 have a direct effect on the growth profile of C. jejuni. The aim of the present study was to further resolve the nature of this interaction in vitro by co-incubation and RNA-sequencing. RESULTS: The co-incubation of C. jejuni with DON resulted in significantly higher bacterial growth rates from 30 h of incubation onwards. On the contrary, the co-incubation of C. jejuni with DOM-1 reduced the CFU counts, indicating that this DON metabolite might contribute to reduce the burden of C. jejuni in birds, altogether confirming in vivo data. Furthermore, the transcriptomic profile of C. jejuni following incubation with either DON or DOM-1 differed. Co-incubation of C. jejuni with DON significantly increased the expression of multiple genes which are critical for Campylobacter growth, particularly members of the Flagella gene family, frr (ribosome-recycling factor), PBP2 futA-like (Fe3+ periplasmic binding family) and PotA (ATP-binding subunit). Flagella are responsible for motility, biofilm formation and host colonization, which may explain the high Campylobacter load in the gut of DON-fed broiler chickens. On the contrary, DOM-1 downregulated the Flagella gene family and upregulated ribosomal proteins. CONCLUSION: The results highlight the adaptive mechanisms involved in the transcriptional response of C. jejuni to DON and its metabolite DOM-1, based on the following effects: (a) ribosomal proteins; (b) flagellar proteins; (c) engagement of different metabolic pathways. The results provide insight into the response of an important intestinal microbial pathogen against DON and lead to a better understanding of the luminal or environmental acclimation mechanisms in chickens.

The circadian rhythm gene Bmal1 ameliorates acute deoxynivalenol-induced liver damage.

Deoxynivalenol (DON) is widely emerging in various grain crops, milk, and wine products, which can trigger different toxic effects on humans and animals by inhalation or ingestion. It also imposes a considerable financial loss on the agriculture and food industry each year. Previous studies have reported acute and chronic toxicity of DON in liver, and liver is not only the main detoxification organ for DON but also the circadian clock oscillator directly or indirectly regulates critical physiologically hepatic functions under different physiological and pathological conditions. However, researches on the association of circadian rhythm in DON-induced liver damage are limited. In the present study, mice were divided into four groups (CON, DON, Bmal1OE, and Bmal1OE + DON) and AAV8 was used to activate (Bmal1) expression in liver. Then mice were gavaged with 5 mg/kg bw/day DON or saline at different time points (ZT24 = 0, 4, 8, 12, 16, and 20 h) in 1 day and were sacrificed 30 min after oral gavage. The inflammatory cytokines, signal transducers, and activators of transcription Janus kinase/signal transducers and activator of transcription 3 (JAKs/STAT3) pathway and bile acids levels were detected by enzyme-linked immunosorbent assay (ELISA), western blotting, and target metabolomics, respectively. The DON group showed significantly elevated interleukin-1ß (IL-1ß), interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α) levels (P < 0.05 for both) and impaired liver function with rhythm disturbances compared to the CON and Bmal1OE groups. At the molecular level, expressions of some circadian clock proteins were significantly downregulated (P < 0.05 for both) and JAKs/STAT3 pathway was activated during DON exposure, accompanied by indicated circadian rhythm disturbance and inflammatory damage. Importantly, Bmal1 overexpression attenuated DON-induced liver damage, while related hepatic bile acids such as cholic acid (CA) showed a decreasing trend in the DON group compared with the CON group. Our study demonstrates a novel finding that Bmal1 plays a critical role in attenuating liver damage by inhibiting inflammatory levels and maintaining bile acids levels under the DON condition. Therefore, Bmal1 may also be a potential molecular target for reducing the hepatotoxic effects of DON in future studies.

Machine Learning Analysis of Hyperspectral Images of Damaged Wheat Kernels.

Fusarium head blight (FHB) is a disease of small grains caused by the fungus Fusarium graminearum. In this study, we explored the use of hyperspectral imaging (HSI) to evaluate the damage caused by FHB in wheat kernels. We evaluated the use of HSI for disease classification and correlated the damage with the mycotoxin deoxynivalenol (DON) content. Computational analyses were carried out to determine which machine learning methods had the best accuracy to classify different levels of damage in wheat kernel samples. The classes of samples were based on the DON content obtained from Gas Chromatography-Mass Spectrometry (GC-MS). We found that G-Boost, an ensemble method, showed the best performance with 97% accuracy in classifying wheat kernels into different severity levels. Mask R-CNN, an instance segmentation method, was used to segment the wheat kernels from HSI data. The regions of interest (ROIs) obtained from Mask R-CNN achieved a high mAP of 0.97. The results from Mask R-CNN, when combined with the classification method, were able to correlate HSI data with the DON concentration in small grains with an R2 of 0.75. Our results show the potential of HSI to quantify DON in wheat kernels in commercial settings such as elevators or mills.

3-keto-DON, but Not 3-epi-DON, Retains the in Planta Toxicological Potential after the Enzymatic Biotransformation of Deoxynivalenol.

Deoxynivalenol (DON) is a secondary fungal metabolite that is associated with many adverse toxicological effects in agriculture as well as human/animal nutrition. Bioremediation efforts in recent years have led to the discovery of numerous bacterial isolates that can transform DON to less toxic derivatives. Both 3-keto-DON and 3-epi-DON were recently shown to exhibit reduced toxicity, compared to DON, when tested using different cell lines and mammalian models. In the current study, the toxicological assessment of 3-keto-DON and 3-epi-DON using in planta models surprisingly revealed that 3-keto-DON, but not 3-epi-DON, retained its toxicity to a large extent in both duckweeds (Lemna minor L.) and common wheat (Triticum aestivum L.) model systems. RNA-Seq analysis revealed that the exposure of L. minor to 3-keto-DON and DON resulted in substantial transcriptomic changes and similar gene expression profiles, whereas 3-epi-DON did not. These novel findings are pivotal for understanding the environmental burden of the above metabolites as well as informing the development of future transgenic plant applications. Collectively, they emphasize the fundamental need to assess both plant and animal models when evaluating metabolites/host interactions.

Plant defense compound triggers mycotoxin synthesis by regulating H2B ub1 and H3K4 me2/3 deposition.

Fusarium graminearum produces the mycotoxin deoxynivalenol (DON) which promotes its expansion during infection on its plant host wheat. Conditional expression of DON production during infection is poorly characterized. Wheat produces the defense compound putrescine, which induces hypertranscription of DON biosynthetic genes (FgTRIs) and subsequently leads to DON accumulation during infection. Further, the regulatory mechanisms of FgTRIs hypertranscription upon putrescine treatment were investigated. The transcription factor FgAreA regulates putrescine-mediated transcription of FgTRIs by facilitating the enrichment of histone H2B monoubiquitination (H2B ub1) and histone 3 lysine 4 di- and trimethylations (H3K4 me2/3) on FgTRIs. Importantly, a DNA-binding domain (bZIP) specifically within the Fusarium H2B ub1 E3 ligase Bre1 othologs is identified, and the binding of this bZIP domain to FgTRIs depends on FgAreA-mediated chromatin rearrangement. Interestingly, H2B ub1 regulates H3K4 me2/3 via the methyltransferase complex COMPASS component FgBre2, which is different from Saccharomyces cerevisiae. Taken together, our findings reveal the molecular mechanisms by which host-generated putrescine induces DON production during F. graminearum infection. Our results also provide a novel insight into the role of putrescine during phytopathogen-host interactions and broaden our knowledge of H2B ub1 biogenesis and crosstalk between H2B ub1 and H3K4 me2/3 in eukaryotes.

Expression of Fusarium pseudograminearum FpNPS9 in wheat plant and its function in pathogenicity.

Fusarium pseudograminearum-induced crown rot causes significant reduction to wheat production worldwide. To date, efforts to develop effective resistance to this disease have been hampered by the quantitative nature of resistance trait and a lack of understanding of the molecular pathogenesis. Non-ribosomal peptides have important roles in development, pathogenicity, and toxins in many plant pathogens, while less is known in F. pseudograminearum. In this work, we studied the expression and function of a nonribosomal peptide gene FpNPS9 in F. pseudograminearum. We determined the expression of FpNPS9 which was significantly up regulated during the infection of wheat. A deletion mutant Δfpnps9 produced in this study displayed a normal growth and conidiation phenotype, however, hyphae polar growth was obviously affected. Deoxynivalenol production in this mutant was significantly reduced and the infection of wheat coleoptiles and wheat spikelet was attenuated. The Δfpnps9 showed serious defects on the extension of infectious hyphae in plant and inhibition of roots elongation compared with the wild type. The complementation assay using a FpNPS9-GFP fusion construct fully restored the defects of the mutant. GFP signal was detected in the germinating conidia and infectious hyphae in coleoptiles of the infected plants. Interestingly, the signal was not observed when it was grown on culture medium, suggesting that the expression of FpNPS9 was regulated by an unknown host factor. This observation was supported by the result of qRT-PCR. In summary, we provided new knowledge on FpNPS9 expression in F. pseudograminearum and its function in F. pseudograminearum pathogenicity in wheat.

Food Poisoning Caused by Deoxynivalenol at a School in Zhuhai, Guangdong, China, in 2019.

Deoxynivalenol (DON) or "vomitoxin" is a mycotoxin produced by Fusarium species. Few food poisoning cases caused by DON have been reported since the 1990s in China. However, on May 16, 2019, the Zhuhai Center for Disease Control and Prevention received a case report from primary school "S" that many students began vomiting after eating breakfast. To discern the cause and control the outbreak effectively, an epidemiological investigation was carried out. This retrospective cohort study defined both suspected and probable cases of food poisoning using ultra-high-performance liquid chromatography coupled with triple quadrupole mass spectrometry to detect 16 mycotoxins simultaneously. A total of 101 cases (14 suspected and 87 probable) were identified, with an overall attack rate of 8.1%. All cases were in grades 1-3. The main symptoms of probable cases were vomiting (100%) and nausea (63%). The average incubation time was 25 min after eating. Comparison of students who ate breakfast provided by the school with those who did not revealed the relative risk was 6.0 (95% confidence intervals [CI] = 2.2-16) among students in grades 1-3. The concentration of DON in the leftover raw breakfast noodles ranged from 6856 to 11,982 µg/kg and 878.3 to 1074.2 µg/kg in leftover cooked noodles. DON exposure was 1.3-1.6 µg/kg body weight for grades 1-2 and 1.7-2.1 µg/kg body weight for grade 3. The attack rate of grade 3 was 4.3 times higher than that for grades 1-2 (95% CI = 3.0-6.3). The food poisoning outbreak on May 16, 2019 in primary school "S" in China, was determined to be caused by DON-contaminated commercial raw noodles.

Prediction of deoxynivalenol toxicokinetics in humans by in vitro-to-in vivo extrapolation and allometric scaling of in vivo animal data.

Deoxynivalenol (DON) is the most prevalent mycotoxin in cereals worldwide. It can cause adverse health effects in humans and animals, and maximum levels in food and feed have been implemented by food authorities based on risk assessments derived from estimated intake levels. The lack of human toxicokinetic data such as absorption, distribution, and elimination characteristics hinders the direct calculation of DON plasma levels and exposure. In the present study, we have, therefore, used in vitro-to-in vivo extrapolation of depletion constants in hepatic microsomes from different species and allometric scaling of reported in vivo animal parameters to predict the plasma clearance [0.24 L/(h × kg)] and volume of distribution (1.24 L/kg) for DON in humans. In addition, we have performed a toxicokinetic study with oral and intravenous administration of DON in pigs to establish benchmark parameters for the in vitro extrapolation approach. The determined human toxicokinetic parameters were then used to calculate the bioavailability (50-90%), maximum concentration, and total exposure in plasma, and urinary concentrations under consideration of typical DON levels in grain-based food products. The results were compared to data from biomonitoring studies in human populations.

Evaluation of the cytotoxic properties, gene expression profiles and secondary signalling responses of cultured cells exposed to fumonisin B1, deoxynivalenol and zearalenone mycotoxins.

Mycotoxins are toxic secondary metabolites produced by a range of fungi and are common contaminants of agricultural crops. These toxins are chemically diverse and structurally stable, enabling them to enter the food chain which can lead to numerous adverse health effects in animals and humans. Although mycotoxin exposure is associated with the development of several cancers, it has proved challenging to show a direct connection between exposure and oncogenic change. This study investigates the in vitro cytotoxicity, molecular mechanisms and secondary signalling responses associated with the exposure to three major mycotoxins, fumonisin B1 (FB1), deoxynivalenol (Don) and zearalenone (Zea). The cytotoxicity of FB1, Don and Zea were investigated in cultured HepG2 and Caco-2 cells using cell viability assays as well as flow cytometry. FB1 proved to be less cytotoxic than its counterparts, while Don and Zea demonstrated high cytotoxicity through an apoptotic mechanism. Expression profiles of 84 genes involved in mediating communication between tumour cells and the cellular mediators of inflammation as well as the innate immune system were also studied. The expression profiles associated with the different mycotoxins were further explored for functional networks, biological functions, canonical pathways, toxicological association as well as to predict network associations between the differentially expressed genes. RT-qPCR revealed the significant differential expression of 46 genes, including the expression of several genes strongly associated with cancer and aberrant inflammatory signalling, after mycotoxin exposure. Aberrant inflammatory signalling seems to be a credible contributing factor that initiates the malignant change observed in cells exposed to mycotoxins.

In Vitro Evaluation of Sub-Lethal Concentrations of Plant-Derived Antifungal Compounds on FUSARIA Growth and Mycotoxin Production.

Phytopathogenic fungi can lead to significant cereal yield losses, also producing mycotoxins dangerous for human and animal health. The fungal control based on the use of synthetic fungicides can be complemented by "green" methods for crop protection, based on the use of natural products. In this frame, the antifungal activities of bergamot and lemon essential oils and of five natural compounds recurrent in essential oils (citronellal, citral, cinnamaldehyde, cuminaldehyde and limonene) have been evaluated against three species of mycotoxigenic fungi (Fusarium sporotrichioides, F. graminearum and F. langsethiae) responsible for Fusarium Head Blight in small-grain cereals. The natural products concentrations effective for reducing or inhibiting the in vitro fungal growth were determined for each fungal species and the following scale of potency was found: cinnamaldehyde > cuminaldehyde > citral > citronellal > bergamot oil > limonene > lemon oil. Moreover, the in vitro mycotoxin productions of the three Fusaria strains exposed to sub-lethal concentrations of the seven products was evaluated. The three fungal species showed variability in response to the treatments, both in terms of inhibition of mycelial growth and in terms of modulation of mycotoxin production that can be enhanced by sub-lethal concentrations of some natural products. This last finding must be taken into account in the frame of an open field application of some plant-derived fungicides.

A NADPH-Dependent Aldo/Keto Reductase Is Responsible for Detoxifying 3-Keto-Deoxynivalenol to 3-epi-Deoxynivalenol in Pelagibacterium halotolerans ANSP101.

Deoxynivalenol (DON), primarily generated by Fusarium species, often exists in agricultural products. It can be transformed to 3-epi-deoxynivalenol (3-epi-DON), with a relatively low toxicity, via two steps. DDH in Pelagibacterium halotolerans ANSP101 was proved to convert DON to 3-keto-deoxynivalenol (3-keto-DON). In the present research, AKR4, a NADPH-dependent aldo/keto reductase from P. halotolerans ANSP101, was identified to be capable of converting 3-keto-DON into 3-epi-DON. Our results demonstrated that AKR4 is clearly a NADPH-dependent enzyme, for its utilization of NADPH is higher than that of NADH. AKR4 functions at a range of pH 5-10 and temperatures of 20-60 °C. AKR4 is able to degrade 89% of 3-keto-DON in 90 min at pH 7 and 50 °C with NADPH as the cofactor. The discovery of AKR4, serving as an enzyme involved in the final step in DON degradation, might provide an option for the final detoxification of DON in food and feed.

Fusarium pseudograminearum biomass and toxin accumulation in wheat tissues with and without Fusarium crown rot symptoms.

Fusarium crown rot (FCR) is an important and devastating disease of wheat (Triticum aestivum) caused by the fungus Fusarium pseudograminearum and related pathogens. Using two distinct susceptible cultivars, we investigated the isolation frequencies of F. pseudograminearum and quantified its biomass accumulation and the levels of the associated toxins deoxynivalenol (DON) and DON-3-glucoside (D3G) in inoculated field-grown wheat plants. We detected F. pseudograminearum in stem, peduncle, rachis, and husk tissues, but not in grains, whereas DON and D3G accumulated in stem, rachis, husk, and grain tissues. Disease severity was positively correlated with the frequency of pathogen isolation, F. pseudograminearum biomass, and mycotoxin levels. The amount of F. pseudograminearum biomass and mycotoxin contents in asymptomatic tissue of diseased plants were associated with the distance of the tissue from the diseased internode and the disease severity of the plant. Thus, apparently healthy tissue may harbor F. pseudograminearum and contain associated mycotoxins. This research helps clarify the relationship between F. pseudograminearum occurrence, F. pseudograminearum biomass, and mycotoxin accumulation in tissues of susceptible wheat cultivars with or without disease symptoms, providing information that can lead to more effective control measures.

The Possible Role of Mycotoxins in the Pathogenesis of Endometrial Cancer.

Endometrial cancer is one of the most common cancer types among women. Many factors can contribute to the development of this disease, including environmental factors and, thus, eating habits. Our study aims to determine the levels of various mycotoxins and their metabolites in the blood serum and endometrial tissue samples of participants with previously proven endometrial cancer and to find possible contributions to cancer development. In the cohort clinical trial, 52 participants aged between 44 and 86 were studied. The participants were divided into two groups: patients or matched controls. All patients had previously histologically diagnosed endometrial cancer. The cancer patients were divided into low-grade endometrioid and low- plus high-grade endometrioid groups. Controls had no history of endometrial malignancy or premalignancy. Blood serum and endometrial tissue samples were obtained from all study patients. We compared the concentrations of total Aflatoxins (Afs), Deoxynivalenol (DON), Ochratoxin-A (OTA), T2-toxin and HT2 toxin (T2/HT2 toxin), Zearalenone (ZEN), alpha-Zearalenol (α-ZOL), and Fumonisin B1 (FB1) in the serum and endometrium between the different study groups. As a result, we can see a significant correlation between the higher levels of Afs and zearalenone and the presence of endometrial cancer. In the case of Afs, DON, OTA, T2/HT2 toxins, ZEN, and alpha-ZOL, we measured higher endometrial concentrations than in serum. Considering the effect of mycotoxins and eating habits on cancer development, our results might lead to further research exploring the relationship between certain mycotoxins and endometrium cancer.

Corrigendum: A survey of Fusarium species and ADON genotype on Canadian wheat grain.

[This corrects the article DOI: 10.3389/ffunb.2022.1062444.].

Endogenic Phenolic Compounds of Barley as Potential Biomarkers Related to Grain Mycotoxin Production and Cultivar Selection.

Barley (Hordeum vulgare L.) is the fourth largest cereal crop in the world. One of the most devastating diseases in barley worldwide is Fusarium head blight (FHB) caused by Fusarium graminearum Schwabe. Several mycotoxins are produced by FHB infection, and deoxynivalenol (DON) is one of them responsible for the deterioration of grain quality. The current limited number of reliable molecular markers makes the development of FHB-resistant cultivars rather difficult and laborious. Moreover, there is a limited number of designed specific biomarkers that could distinguish the FHB resistance and mycotoxin accumulation in barley cultivars. This study investigated the phenolic compounds of ten different Canadian barley cultivars, grown in artificially FHB-infected and non-infected field trials. The enzyme-linked immunosorbent assay (ELISA) was used to assess the presence of DON in the harvested infected grains of each tested variety. High-performance liquid chromatography (HPLC) analysis was performed using both infected and non-infected samples. We identified differences among cultivars tested in non-infected samples through quantitative analysis of free and bound phenolic compounds. The resistant cultivars showed higher amounts of major bound phenolic compounds compared to the susceptible check CDC Bold. Additionally, the FHB-infected cultivars produced significantly higher amounts of sinapic acid (SIN) () and catechin (CAT) in the soluble free form of phenolics in barley compared to the non-infected subjects. This study suggests that phenolic compounds in barley could allow barley breeders to precisely identify and develop FHB-resistant barley germplasm and cultivars.

Venturicidin A Is a Potential Fungicide for Controlling Fusarium Head Blight by Affecting Deoxynivalenol Biosynthesis, Toxisome Formation, and Mitochondrial Structure.

Fusarium graminearum, which causes Fusarium head blight (FHB) in cereals, is one of the most devastating fungal diseases by causing great yield losses and mycotoxin contamination. A major bioactive ingredient, venturicidin A (VentA), was isolated from Streptomyces pratensis S10 mycelial extract with an activity-guided approach. No report is available on antifungal activity of VentA against F. graminearum and effects on deoxynivalenol (DON) biosynthesis. Here, VentA showed a high antagonistic activity toward F. graminearum with an EC50 value of 3.69 µg/mL. As observed by scanning electron microscopy, after exposure to VentA, F. graminearum conidia and mycelia appeared abnormal. Different dyes staining revealed that VentA increased cell membrane permeability. In growth chamber and field trials, VentA effectively reduced disease severity of FHB. Moreover, VentA inhibited DON biosynthesis by reducing pyruvic acid, acetyl-CoA production, and accumulation of reactive oxygen species (ROS) and then inhibiting trichothecene (TRI) genes expression and toxisome formation. These results suggest that VentA is a potential fungicide for controlling FHB.

In-vitro assessment of a novel plant rhizobacterium, Citrobacter freundii, for degrading and biocontrol of food mycotoxin deoxynivalenol.

Deoxynivalenol (DON) is one of the most harmful and well-known toxins present in food and animal feed throughout the world. Citrobacter freundii (C. freundii-ON077584), a novel DON-degrading strain, was isolated from rice root-linked soil samples. The degrading properties, including DON concentrations, incubation pH, incubation temperatures, bacterial concentrations, and acid treatment effect on degradation, were evaluated. At pH 7 and an incubation temperature of 37 °C, C. freundii demonstrated the capability to degrade more than 90% of DON. The degraded products of DON were identified as 3-keto-DON and DOM-1, which were confirmed by High Performance Liquid Chromatography (HPLC) and Ultra-Performance Liquid Chromatography hyphenated with Tandem Mass Spectrometry (UPLC-MS/MS) analyses. The mechanism of DON degradation into 3-keto-DON and DOM-1 by this bacterial strain will be further explored to identify and purify novel degrading enzymes that can be cloned to the microorganism and added to the animal feed to degrade the DON in the digestion tract.

The COP9 signalosome complex regulates fungal development and virulence in the wheat scab fungus Fusarium graminearum.

The COP9 signalosome (Csn) complex is an evolutionarily conserved complex that regulates various important cellular processes. However, the function of the Csn complex in pathogenic fungi remains elusive. Here, the distribution of Csn subunits in the fungal kingdom was surveyed, and their biological functions were systematically characterized in the fungal pathogen Fusarium graminearum, which is among the top 10 plant fungal pathogens. The results obtained from bioinformatic analyses suggested that the F. graminearum Csn complex consisted of seven subunits (Csn1-Csn7) and that Csn5 was the most conserved subunit across the fungi kingdom. Yeast two-hybrid assays demonstrated that the seven Csn subunits formed a complex in F. graminearum. The Csn complex was localized to both the nucleus and cytoplasm and necessary for hyphal growth, asexual and sexual development and stress response. Transcriptome profiling revealed that the Csn complex regulated the transcription abundance of TRI genes necessary for mycotoxin deoxynivalenol (DON) biosynthesis, subsequently regulating DON production to control fungal virulence. Collectively, the roles of the Csn complex in F. graminearum were comprehensively analyzed, providing new insights into the functions of the Csn complex in fungal virulence and suggesting that the complex may be a potential target for combating fungal diseases.

Subclinical doses of dietary fumonisins and deoxynivalenol cause cecal microbiota dysbiosis in broiler chickens challenged with Clostridium perfringens.

Fusarium toxins are one of the most common contaminants in poultry diets. The co-occurrence of fumonisins (FUM) and deoxynivalenol (DON), even at a subclinical dose, negatively affects the growth performance, intestinal integrity and induce subclinical necrotic enteritis in broiler chickens. Loss of gut integrity can be expected to alter the intestinal microbiota's composition. The objective of this study was to identify the effects of combined FUM and DON on the cecal microbiome profile and predicted metabolic functions and a short chain fatty acid profile in broilers challenged with Clostridium perfringens. A total of 240 1 day-old chicks were randomly assigned to two treatments: a control diet and the control diet with 3 mg/kg FUM + 4 mg/kg DON each with eight replications. All the birds were received cocci vaccine at d0. All birds in both treatment groups were challenged with C. perfringens 1 × 108 CFU via feed on d 19 and 20 to achieve 5% mortality. On d 35, the FUM and DON contaminated diet numerically (P = 0.06) decreased the body weight gain (BWG) by 84 g compared to the control group. The bacterial compositions of the cecal contents were analyzed by sequencing the V3-V4 region of the 16S rRNA gene. Overall, microbial richness and diversity increased (P < 0.02) during the studied period (d 21-35). Cecal contents of birds in the FUM + DON group had greater (P < 0.05) microbial evenness and diversity (Shannon index) compared to the control group. FUM + DON exposure decreased (P = 0.001) the relative abundance of Proteobacteria in the cecal content, compared to the control group. The combined FUM + DON significantly increased the relative abundance of the Defluviitaleaceae and Lachnospiraceae families (P < 0.05) but decreased the abundances of the Moraxellaceae and Streptococcaceae (P < 0.05) compared to the control group birds. At the genus level, FUM + DON exposure decreased (P < 0.05) Acinetobacter and Pseudomonas abundance and had a tendency (P = 0.08) to decrease Thermincola abundance compared to the control group. In the ileum, no NE-specific microscopic abnormalities were found; however, the tip of the ileal villi were compromised. The present findings showed that dietary FUM and DON contamination, even at subclinical levels, altered cecal microbial composition, dysregulated intestinal functions, and impaired the gut immune response, potentially predisposing the birds to necrotic enteritis.

A survey of Fusarium species and ADON genotype on Canadian wheat grain.

Introduction: Wheat is a staple food that is important to global food security, but in epidemic years, fungal pathogens can threaten production, quality, and safety of wheat grain. Globally, one of the most important fungal diseases of wheat is Fusarium head blight (FHB). This disease can be caused by several different Fusarium species with known differences in aggressiveness and mycotoxin-production potential, with the trichothecene toxin deoxynivalenol (DON) and its derivatives being of particular concern. In North America, the most predominant species causing FHB is F. graminearum, which has two distinct sub-populations that are commonly classified into two main chemotypes/genotypes based on their propensity to form trichothecene derivatives, namely 15-acetyldeoxynivalenol (15-ADON) and 3-acetyldeoxynivalenol (3-ADON). Materials and methods: We used a panel of 13 DNA markers to perform species and ADON genotype identification for 55, 444 wheat kernels from 7, 783 samples originating from across Canada from 2014 to 2020. Results and discussion: Based on single-seed analyses, we demonstrate the relationships between Fusarium species and trichothecene chemotype with sample year, sample location, wheat species (hexaploid and durum wheat), severity of Fusarium damaged kernels (FDK), and accumulation of DON. Results indicate that various Fusarium species are present across wheat growing regions in Canada; however, F. graminearum is the most common species and 3-ADON the most common genotype. We observed an increase in the occurrence of the 3-ADON genotype, particularly in the western Prairie regions. Our data provides important information on special-temporal trends in Fusarium species and chemotypes that can aid with the implementation of integrated disease management strategies to control the detrimental effects of this devastating disease.