Oral exposure to culture material extract containing fumonisins predisposes swine to the development of pneumonitis caused by Pasteurella multocida

Evaluating the combined and individual cytotoxic effect of beauvericin, enniatin B and ochratoxin a on breast cancer cells, leukemia cells, and fresh peripheral blood mononuclear cells

Beauvericin (BEA), Enniatin B (ENN B), and Ochratoxin A (OTA) are mycotoxins produced by fungi species. Their main effect on several organs and systems is associated with chronic exposure going from immunotoxicity, estrogenic disorders, and renal failure to cancer (in animals and humans). OTA belongs to Group 1 according to the International Agency for Research in Cancer (IARC) and it has legislated limited values; not happening for BEA nor ENN B. Exposure to mixtures of mycotoxins occurs through food intake in daily consumption. The aim of this study was to evaluate the implication of BEA, ENN B, and OTA individually and combined in producing cytotoxicity in cells for immunological studies and cancer cell lines (human leukemia cells (HL-60), fresh human peripheral blood mononuclear cells (PBMCs), and human breast cancer (MDA-MB-231) cells). Cells were treated for 4 h and 24 h at different concentrations of BEA, ENN B, and OTA, respectively. Viability assays were carried out by flow cytometry using DAPI (4',6-diamindino-2-phenylindole, dihydrochloride) as a viability dye and the potential effects of synergism, addition, and antagonism were assessed through the Chou and Talalay method. Individual OTA treatment exerted the greatest cytotoxicity for PBMC cells (IC50 0.5 μM) while ENN B for HL-60 (IC50 0.25 μM) and MDA-MB-231 (IC50 0.15 μM). In binary combination [ENN B + OTA] resulted in exerting the greatest cytotoxicity for HL-60 and MDA-MB-231 cells; while [BEA + OTA] in PBMC cells. The triple combination resulted in being highly cytotoxic for PBMC cells compared to HL-60 and MDA-MB-231 cells. In summary, PBMC cells were the most sensible cells for all three mycotoxins and the presence of OTA in any of the combinations had the greatest toxicity causing synergism as the most common cytotoxic effect.

Foodborne Diseases Due to Underestimated Hazard of Joint Mycotoxin Exposure at Low Levels and Possible Risk Assessment

The subject of this review paper is to evaluate the underestimated hazard of multiple mycotoxin exposure of animals/humans for the appearance of foodborne ailments and diseases. The significance of joint mycotoxin interaction in the development of foodborne diseases is discussed, and appropriate conclusions are made. The importance of low feed/food levels of some target mycotoxins co-contaminations in food and feedstuffs for induction of target foodborne mycotoxicoses is also studied in the available literature. The appropriate hygiene control and the necessary risk assessment in regard to possible hazards for animals and humans are also discussed, and appropriate suggestions are made. Some internationally recognized prophylactic measures, management of the risk, and the necessity of elaboration of new international regulations in regard to the maximum permitted levels are also carefully discussed and analysed in the cases of multiple mycotoxin contaminations. The necessity of harmonization of mycotoxin regulations and control measures at international levels is also discussed in order to facilitate food trade between the countries and to ensure global food safety.

Systematic review of animal-based indicators to measure thermal, social, and immune-related stress in pigs

The intense nature of pig production has increased the animals’ exposure to stressful conditions, which may be detrimental to their welfare and productivity. Some of the most common sources of stress in pigs are extreme thermal conditions (thermal stress), density and mixing during housing (social stress), or exposure to pathogens and other microorganisms that may challenge their immune system (immune-related stress). The stress response can be monitored based on the animals’ coping mechanisms, as a result of specific environmental, social, and health conditions. These animal-based indicators may support decision making to maintain animal welfare and productivity. The present study aimed to systematically review animal-based indicators of social, thermal, and immune-related stresses in farmed pigs, and the methods used to monitor them. Peer-reviewed scientific literature related to pig production was collected using three online search engines: ScienceDirect, Scopus, and PubMed. The manuscripts selected were grouped based on the indicators measured during the study. According to our results, body temperature measured with a rectal thermometer was the most commonly utilized method for the evaluation of thermal stress in pigs (87.62%), as described in 144 studies. Of the 197 studies that evaluated social stress, aggressive behavior was the most frequently-used indicator (81.81%). Of the 535 publications examined regarding immune-related stress, cytokine concentration in blood samples was the most widely used indicator (80.1%). Information about the methods used to measure animal-based indicators is discussed in terms of validity, reliability, and feasibility. Additionally, the introduction and wide spreading of alternative, less invasive methods with which to measure animal-based indicators, such as cortisol in saliva, skin temperature and respiratory rate via infrared thermography, and various animal welfare threats via vocalization analysis are highlighted. The information reviewed was used to discuss the feasible and most reliable methods with which to monitor the impact of relevant stressors commonly presented by intense production systems on the welfare of farmed pigs.

Tissular Genomic Responses to Oral FB1 Exposure in Pigs

Fumonisin B1 (FB1) is a widespread mycotoxin produced by fungal Fusarium species—mainly in maize, one of the plants most commonly used for food and feed. Pigs and horses are the animal species most susceptible to this mycotoxin. FB1 exposure can cause highly diverse clinical symptoms, including hepatotoxicity, immunotoxicity, and intestinal barrier function disturbance. Inhibition of ceramide synthetase is a well-understood ubiquitous molecular mechanism of FB1 toxicity, but other more tissue-specific effects remain to be elucidated. To investigate the effects of FB1 in different exposed tissues, we cross-analyzed the transcriptomes of fours organs: liver, jejunum, jejunal Peyer’s patches, and spleen. During a four-week study period, pigs were fed a control diet or a FB1-contaminated diet (10 mg/kg feed). In response to oral FB1 exposure, we observed common biological processes in the four organs, including predominant and recurrent processes (extracellular matrix organization, integrin activation, granulocyte chemotaxis, neutrophil migration, and lipid and sterol homeostasis), as well as more tissue-specific processes that appeared to be related to lipid outcomes (cell cycle regulation in jejunum, and gluconeogenesis in liver).

Phytic acid modulates the morphology, immunological response of cytokines and β-defensins in porcine intestine exposed to deoxynivalenol and fumonisin B1

Occurrence of mycotoxins in agricultural products represents a risk for human and animal health. Therefore, there is a requirement of strategies to mitigate their harmful impacts. This study investigated the effects of phytic acid (IP6) on the immunological response of pro-(interleukin (IL)-1β, IL-6, IL-8, IL-10, interferon (IFN)-γ, tumour necrosis factor (TNF)-α) and anti-inflammatory (IL-10) cytokines and β-defensins 1 (pBD-1) and 2 (pBD-2) in porcine jejunal explants exposed to deoxynivalenol (DON) and fumonisin B1 (FB1). The explants were exposed to the following treatments: control, DON (10 μM), DON plus IP6 2.5 mM or 5 mM, FB1 (70 μM), FB1 IP6 plus 2.5 or 5 mM. The expression levels of the cytokines were measured by RT-qPCR. The exposure to FB1 and DON induced intestinal lesions. The presence of 2.5 and 5 mM IP6 inhibited the morphological changes induced by the mycotoxins. The explants exposed to DON showed an increase in the expression of IL-1β and IL-8 and a decrease in the levels of IL-6, IFN-γ, IL-10 and pBD-2. IP6 (5 mM) decreased the expression of IL-8 and increased the expression in pBD-1 and 2 compared to DON alone. FB1 induced a significant decrease in the levels of most of the pro-inflammatory cytokines, IL-10 and pBD-1, and an increase in IL-1β expression. The addition of IP6 5 mM induced significant increase in TNF-α expression compared to FB1. Taken together, the results suggest IP6 modulates immunological changes induced by DON and FB1 on intestinal mucosa resulting in beneficial effects that contribute to intestinal homeostasis and health.

Research Progress on Fumonisin B1 Contamination and Toxicity: A Review

Fumonisin B1 (FB1), belonging to the member of fumonisins, is one of the most toxic mycotoxins produced mainly by Fusarium proliferatum and Fusarium verticillioide. FB1 has caused extensive contamination worldwide, mainly in corn, rice, wheat, and their products, while it also poses a health risk and is toxic to animals and human. It has been shown to cause oxidative stress, endoplasmic reticulum stress, cellular autophagy, and apoptosis. This review focuses on the current stage of FB1 contamination, its toxic effects of acute toxicity, immunotoxicity, organ toxicity, and reproductive toxicity on animals and humans. The potential toxic mechanisms of FB1 are discussed. One of the main aims of the work is to provide a reliable reference strategy for understanding the occurrence and toxicity of FB1.

Fumonisins at Doses below EU Regulatory Limits Induce Histological Alterations in Piglets

Fumonisins (FBs) are mycotoxins produced by Fusarium species that can contaminate human food and animal feed. Due to the harmful effects of FBs on animals, the European Union (EU) defined a recommendation of a maximum of 5 mg FBs (B1 + B2)/kg for complete feed for swine and 1 µg FBs/kg body weight per day as the tolerable daily intake for humans. The aim of this study was to evaluate the toxicity of dietary exposure to low doses of FBs, including a dose below the EU regulatory limits. Four groups of 24 weaned castrated male piglets were exposed to feed containing 0, 3.7, 8.1, and 12.2 mg/kg of FBs for 28 days; the impact was measured by biochemical analysis and histopathological observations. Dietary exposure to FBs at a low dose (3.7 mg/kg of feed) significantly increased the plasma sphinganine-to-sphingosine ratio. FBs-contaminated diets led to histological modifications in the intestine, heart, lung, lymphoid organs, kidney, and liver. The histological alterations in the heart and the intestine appeared at the lowest dose of FBs-contaminated diet (3.7 mg/kg feed) and in the kidney at the intermediate dose (8.1 mg/kg feed). At the highest dose tested (12.2 mg/kg feed), all the organs displayed histological alterations. This dose also induced biochemical modifications indicative of kidney and liver alterations. In conclusion, our data indicate that FBs-contaminated diets at doses below the EU regulatory limit cause histological lesions in several organs. This study suggests that EU recommendations for the concentration of FBs in animal feed, especially for swine, are not sufficiently protective and that regulatory doses should be modified for better protection of animal health.

Enzymatic hydrolysis of fumonisins in the gastrointestinal tract of broiler chickens

Fumonisins (FB) are among the most frequently detected mycotoxins in feedstuffs and finished feed, and recent data suggest that the functions of the gastrointestinal tract (GIT) in poultry species might be compromised at doses ranging from 10 to 20 mg/kg, close to field incidences and below the US and EU guidelines. Strategies are therefore necessary to reduce the exposure of poultry to FB. In the present study, we assessed the efficacy of fumonisin esterase FumD (EC 3.1.1.87, commercial name FUMzyme®) to cleave the tricarballylic acid side chains of FB, leading to the formation of non-toxic hydrolyzed fumonisins in the GIT of broiler chickens. Broiler chickens were fed for 14 d (7 to 21 d of age) 3 different diets (6 birds/cage, 6 cages/diet), i) control feed (negative control group), ii) feed contaminated with 10 mg FB/kg (FB group), and iii) feed contaminated with 10 mg FB/kg and supplemented with 100 units of FUMzyme®/kg (FB+FUMzyme® group). To determine the degree of reduction of FB in the GIT, 2 characteristics were analyzed. First, the sphinganine-to-sphingosine ratio in the serum and liver was determined as a biomarker of effect for exposure to FB. Second, the concentration of fumonisin B1 and its hydrolyzed forms was evaluated in the gizzard, the proximal and distal parts of the small intestine, and the excreta. Significantly reduced sphinganine-to-sphingosine ratios in the serum and liver of the FB+FUMzyme® group (serum: 0.15 ± 0.01; liver: 0.17 ± 0.01) compared to the FB group (serum: 0.20 ± 0.01; liver: 0.29 ± 0.03) proved that supplementation of broiler feed with FUMzyme® was effective in partially counteracting the toxic effect of dietary FB. Likewise, FB concentrations in digesta and excreta were significantly reduced in the FB+FUMzyme® group compared to the FB group (P < 0.05; up to 75%). FUMzyme® furthermore partially counteracted FB-induced up-regulation of cytokine gene expression (IL-8 and IL-10) in the jejunum. The FB group showed significantly higher gene expression of IL-8 and IL-10 compared to the negative control group (IL-8: fold change = 2.9 ± 1.1, P < 0.05; IL-10: fold change = 3.6 ± 1.4, P < 0.05), whereas IL-8 and IL-10 mRNA levels were not significantly different in the FB+FUMzyme®® group compared to the other 2 groups. In conclusion, FUMzyme® is suitable to detoxify FB in chickens and maintain gut functions.

Clinical impact of deoxynivalenol, 3-acetyl-deoxynivalenol and 15-acetyl-deoxynivalenol on the severity of an experimental Mycoplasma hyopneumoniae infection in pigs

Background

The mycotoxin deoxynivalenol (DON) is highly prevalent in cereals in moderate climates and therefore pigs are often exposed to a DON-contaminated diet. Pigs are highly susceptible to DON and intake of DON-contaminated feed may lead to an altered immune response and may influence the pathogenesis of specific bacterial diseases. Therefore, the maximum guidance level in feed is lowest in this species and has been set at 900 μg/kg feed by the European Commission. This study aimed to determine the effect of in-feed administration of a moderately high DON concentration (1514 μg/kg) on the severity of an experimental Mycoplasma hyopneumoniae (M. hyopneumoniae) infection in weaned piglets. Fifty M. hyopneumoniae-free piglets were assigned at 30 days of age [study day (D)0] to four different groups: 1) negative control group (NCG; n = 5), 2) DON-contaminated group (DON; n = 15), 3) DON-contaminated and M. hyopneumoniae-inoculated group (DONMHYO; n = 15), 4) M. hyopneumoniae-inoculated group (MHYO; n = 15). The piglets were fed the experimental diets ad libitum for five weeks and were monitored during this period and euthanized at day 35 [27 days post infection (DPI)] or 36 (28 DPI). The main parameters under investigation were macroscopic lung lesions (MLL) at euthanasia, respiratory disease score (RDS) from day 8 until day 35, histopathologic lesions and log copies of M. hyopneumoniae DNA detected by qPCR, determined at the day of euthanasia.

Results

No significant difference was obtained for MLL at euthanasia, RDS (8–35), histopathologic lung lesions and log copies of M. hyopneumoniae DNA in the DONMHYO and MHYO group and consequently, no enhancement of the severity of the M. hyopneumoniae infection could be detected in the DONMHYO compared to the MHYO group.

Conclusions

Under present conditions, the findings imply that feed contaminated with DON (1514 μg/kg) provided to weaned pigs for five weeks did not increase the severity of an experimental M. hyopneumoniae infection. Further research is needed to investigate the impact of DON on M. hyopneumoniae infections in a multi-mycotoxin and multi-pathogen environment.

Risks for animal health related to the presence of fumonisins, their modified forms and hidden forms in feed

Fumonisins, mycotoxins primarily produced by Fusarium verticillioides and Fusarium proliferatum, occur predominantly in cereal grains, especially in maize. The European Commission asked EFSA for a scientific opinion on the risk to animal health related to fumonisins and their modified and hidden forms in feed. Fumonisin B1 (FB 1), FB 2 and FB 3 are the most common forms of fumonisins in feedstuffs and thus were included in the assessment. FB 1, FB 2 and FB 3 have the same mode of action and were considered as having similar toxicological profile and potencies. For fumonisins, the EFSA Panel on Contaminants in the Food Chain (CONTAM) identified no-observed-adverse-effect levels (NOAELs) for cattle, pig, poultry (chicken, ducks and turkeys), horse, and lowest-observed-adverse-effect levels (LOAELs) for fish (extrapolated from carp) and rabbits. No reference points could be identified for sheep, goats, dogs, cats and mink. The dietary exposure was estimated on 18,140 feed samples on FB 1-3 representing most of the feed commodities with potential presence of fumonisins. Samples were collected between 2003 and 2016 from 19 different European countries, but most of them from four Member States. To take into account the possible occurrence of hidden forms, an additional factor of 1.6, derived from the literature, was applied to the occurrence data. Modified forms of fumonisins, for which no data were identified concerning both the occurrence and the toxicity, were not included in the assessment. Based on mean exposure estimates, the risk of adverse health effects of feeds containing FB 1-3 was considered very low for ruminants, low for poultry, horse, rabbits, fish and of potential concern for pigs. The same conclusions apply to the sum of FB 1-3 and their hidden forms, except for pigs for which the risk of adverse health effect was considered of concern.

Identification of Signaling Pathways Targeted by the Food Contaminant FB1: Transcriptome and Kinome Analysis of Samples from Pig Liver and Intestine

SCOPE

Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium species. In mammals, this toxin causes widespread organ-specific damage; it promotes hepatotoxicity, is immunotoxic, alters intestinal functions etc. Despite its inhibitory effect on de novo ceramide synthesis, its molecular mechanism of action and toxicity is not totally elucidated.

METHODS AND RESULTS

To explore the mechanism of FB1 toxicity, we analyzed the transcriptome and the kinome of two organs targeted by FB1: the liver and the jejunum. Pigs were fed for 4 weeks a control diet or a FB1-contaminated diet (10 mg/kg). As expected, FB1-exposed pigs gained less weight and displayed a higher sphinganine/sphingosine ratio. Comparison of the transcriptomes and the kinomes of treated versus control pigs showed striking differences. Among the disrupted pathways in liver and jejunum, we highlight Protein Kinase B (AKT) / Phosphatase and tensin homolog (PTEN) at the intersection of the FB1-modulated pathways.

CONCLUSION

Most of the effects of FB1 are mediated by the regulation of ceramide level, which influences protein phosphatase 2 (PP2A) and the phosphoinositide 3-kinase (PI3K)/AKT signaling pathway. This pathway might be a new target to counteract toxic effect of Fumonisin B1, which is one of the most spread food contaminant in the world.

1H NMR and MVA metabolomic profiles of urines from piglets fed with boluses contaminated with a mixture of five mycotoxins

Metabolic profile of urine from piglets administered with single boluses contaminated with mycotoxin mixture (deoxynivalenol, aflatoxin B1, fumonisin B1, zearalenone, and ochratoxin A) were studied by 1H NMR spectroscopy and chemometrics (PCA, PLS-DA, and OPLS-DA). The mycotoxin levels were close to the established maximum and guidance levels for animal feed (2003/100/EC and 2006/576/EC). Urine samples were obtained from four groups of four piglets before (control, C) or within 24 h (treated, T) after receiving a contaminated boluses with increasing doses of mycotoxins (boluses 1-4). For the two highest dose groups, the urines were collected also after one week of wash out (W). For the two lowest doses groups no significant differences between the C and T samples were observed. By contrast, for the two highest doses groups the T urines separated from the controls for a higher relative content of creatinine, p-cresol glucuronide and phenyl acetyl glycine and lower concentration of betaine and TMAO. Interestingly, a similar profile was found for both W and T urines suggesting, at least for the highest doses used, serious alteration after a single bolus of mycotoxin mixture.

Intestinal toxicity of the type B trichothecene mycotoxin fusarenon-X: whole transcriptome profiling reveals new signaling pathways

The few data available on fusarenon-X (FX) do not support the derivation of health-based guidance values, although preliminary results suggest higher toxicity than other regulated trichothecenes. Using histo-morphological analysis and whole transcriptome profiling, this study was designed to obtain a global view of the intestinal alterations induced by FX. Deoxynivalenol (DON) served as a benchmark. FX induced more severe histological alterations than DON. Inflammation was the hallmark of the molecular toxicity of both mycotoxins. The benchmark doses for the up-regulation of key inflammatory genes by FX were 4- to 45-fold higher than the previously reported values for DON. The transcriptome analysis revealed that both mycotoxins down-regulated the peroxisome proliferator-activated receptor (PPAR) and liver X receptor - retinoid X receptor (LXR-RXR) signaling pathways that control lipid metabolism. Interestingly, several pathways, including VDR/RXR activation, ephrin receptor signaling, and GNRH signaling, were specific to FX and thus discriminated the transcriptomic fingerprints of the two mycotoxins. These results demonstrate that FX induces more potent intestinal inflammation than DON. Moreover, although the mechanisms of toxicity of both mycotoxins are similar in many ways, this study emphasize specific pathways targeted by each mycotoxin, highlighting the need for specific mechanism-based risk assessments of Fusarium mycotoxins.

Grape Pomace, an Agricultural Byproduct Reducing Mycotoxin Absorption: In Vivo Assessment in Pig Using Urinary Biomarkers

The efficacy of four agricultural byproducts (ABPs) and two commercial binders (CBs) to reduce the gastrointestinal absorption of a mixture of mycotoxins was tested in piglets using urinary mycotoxin biomarkers as indicator of the absorbed mycotoxins. Twenty-eight piglets were administered a bolus contaminated with the mycotoxin mixture containing or not ABP or CB. Twenty-four hour urine was collected and analyzed for mycotoxin biomarkers by using a multiantibody immunoaffinity-based LC-MS/MS method. Each bolus contained 769 μg of fumonisin B1 (FB1), 275 μg of deoxynivalenol (DON), 29 μg of zearalenone (ZEN), 6.5 μg of aflatoxin B1 (AFB1) and 6.6 μg of ochratoxin A (OTA) corresponding to 2.2, 0.8, 0.08, 0.02, and 0.02 μg/g in the daily diet, respectively. The percentage of ABP in each bolus was 50%, whereas for the two CBs the percentages were 5.2 and 17%, corresponding to 2.8, 0.3, and 0.9% in the daily diet, respectively. The reduction of mycotoxin absorption was up to 69 and 54% for ABPs and CBs, respectively. White grape pomace of Malvasia was the most effective material as it reduced significantly (p < 0.05) urinary mycotoxin biomarker of AFB1 (67%) and ZEN (69%), whereas reductions statistically not significant were observed for FB1 (57%), DON (40%), and OTA (27%). This study demonstrates that grape pomace reduces the gastrointestinal absorption of mycotoxins. This agricultural byproduct can be considered an alternative to commercial products and used in the feed industries as an effective, cheap, and natural binder for multiple mycotoxins.

Feed exposure to FB1 can aggravate pneumonic damages in pigs provoked by P. multocida

The possible interaction between Pasteurella multocida and the mycotoxin fumonisin B1 (FB1), recognised as one of the most often food/feed contaminant, was studied with the aim to evaluate whether and how FB1 can influence and/or complicate the development and severity of various pathological damages provoked by Pasteurella multocida in some internal organs of pigs. Heavier lung pathology was seen in pigs experimentally infected with Pasteurella multocida, when the same were exposed to 20ppm dietary levels of fumonisin B1 (FB1) as was assessed by gross pathology, pathomorphological examinations, clinical biochemistry and some immunological investigations. The most typical damages in FB1 treated pigs were the strong oedema in the lung and the slight oedema in the other internal organs and mild degenerative changes in the kidneys, whereas the typical pathomorphological findings in pigs infected with Pasteurella multocida was broncho-interstitial pneumonia. FB1 was found to aggravate pneumonic changes provoked by P. multocida in the cranial lobes of the lung and to complicate pneumonic damages with interstitial oedema in the lung. No macroscopic damages were observed in the pigs infected only with Pasteurella multocida. It can be concluded that the feed intake of FB1 in pigs may complicate or exacerbate the course of P. multocida serotype A infection.

Microbial biotransformation of DON: molecular basis for reduced toxicity

Bacteria are able to de-epoxidize or epimerize deoxynivalenol (DON), a mycotoxin, to deepoxy-deoxynivalenol (deepoxy-DON or DOM-1) or 3-epi-deoxynivalenol (3-epi-DON), respectively. Using different approaches, the intestinal toxicity of 3 molecules was compared and the molecular basis for the reduced toxicity investigated. In human intestinal epithelial cells, deepoxy-DON and 3-epi-DON were not cytotoxic, did not change the oxygen consumption or impair the barrier function. In intestinal explants, exposure for 4 hours to 10 μM DON induced intestinal lesions not seen in explants treated with deepoxy-DON and 3-epi-DON. A pan-genomic transcriptomic analysis was performed on intestinal explants. 747 probes, representing 323 genes, were differentially expressed, between DON-treated and control explants. By contrast, no differentially expressed genes were observed between control, deepoxy-DON and 3-epi-DON treated explants. Both DON and its biotransformation products were able to fit into the pockets of the A-site of the ribosome peptidyl transferase center. DON forms three hydrogen bonds with the A site and activates MAPKinases (mitogen-activated protein kinases). By contrast deepoxy-DON and 3-epi-DON only form two hydrogen bonds and do not activate MAPKinases. Our data demonstrate that bacterial de-epoxidation or epimerization of DON altered their interaction with the ribosome, leading to an absence of MAPKinase activation and a reduced toxicity.

Impact of mycotoxin on immune response and consequences for pig health

Mycotoxins are fungal secondary metabolites detected in many agricultural commodities, especially cereals. Due to their high consumption of cereals, pigs are exposed to these toxins. In the European Union, regulations and/or recommendations exist in pig feed for aflatoxins, ochratoxin A, fumonisins, zearalenone, and trichothecenes, deoxynivalenol and T-2 toxin. These mycotoxins have different toxic effects, but they all target the immune system. They have immunostimulatory or immunosuppressive effects depending on the toxin, the concentration and the parameter investigated. The immune system is primarily responsible for defense against invading organisms. The consequences of the ingestion of mycotoxin-contaminated feed are an increased susceptibility to infectious diseases, a reactivation of chronic infection and a decreased vaccine efficacy. In this review we summarized the data available on the effect of mycotoxins on the immune system and the consequences for pig health.

Effects of Mycotoxins on mucosal microbial infection and related pathogenesis

Mycotoxins are fungal secondary metabolites detected in many agricultural commodities and water-damaged indoor environments. Susceptibility to mucosal infectious diseases is closely associated with immune dysfunction caused by mycotoxin exposure in humans and other animals. Many mycotoxins suppress immune function by decreasing the proliferation of activated lymphocytes, impairing phagocytic function of macrophages, and suppressing cytokine production, but some induce hypersensitive responses in different dose regimes. The present review describes various mycotoxin responses to infectious pathogens that trigger mucosa-associated diseases in the gastrointestinal and respiratory tracts of humans and other animals. In particular, it focuses on the effects of mycotoxin exposure on invasion, pathogen clearance, the production of cytokines and immunoglobulins, and the prognostic implications of interactions between infectious pathogens and mycotoxin exposure.

Foodborne mycotoxicoses, risk assessment and underestimated hazard of masked mycotoxins and joint mycotoxin effects or interaction

The existing hazard of joint mycotoxin exposure of animals/humans and the significance of masked mycotoxins in foods or feeds and their respective contributions to the development of some food born mycotoxicoses is briefly reviewed. The importance of joint mycotoxin interaction in the complex etiology of some foodborn mycotoxicoses is covered in depth. The toxicity of low contamination levels of some combinations of mycotoxins ingested often by farm animals was carefully studied. The appropriate hygiene control and the necessary risk assessment in regard to mycotoxin contamination of foods and feeds are briefly analyzed and some useful prophylactic measures and management of the risk of mycotoxin contamination, in addition to tolerable daily intakes are also described. A reference is also made to the most suitable methods of veterinary hygiene control in some practical situations in order to prevent mycotoxins contaminating commercial food commodities and endangering public health.

New insights into the organ-specific adverse effects of fumonisin B1: comparison between lung and liver

Fumonisin B1 (FB1) is a well-known inhibitor of de novo sphingolipid biosynthesis, due to its ability to inhibit ceramide synthases (CerS) activity. In mammals, this toxin triggers broad clinical symptoms with multi-organ dysfunction such as hepatotoxicity or pulmonary edema. The molecular mechanism of CerS inhibition by FB1 remains unknown. Due to the existence of six mammalian CerS isoforms with a tissue-specific expression pattern, we postulated that the organ-specific adverse effects of FB1 might be due to different CerS isoforms. The sphingolipid contents of lung and liver were compared in normal and FB1-exposed piglets (gavage with 1.5 mg FB1/kg body weight daily for 9 days). The effect of the toxin on each CerS was deduced from the analysis of its effects on individual ceramide (Cer) and sphingomyelin (SM) species. As expected, the total Cer content decreased by half in the lungs of FB1-exposed piglets, while in contrast, total Cer increased 3.5-fold in the livers of FB1-exposed animals. Our data also indicated that FB1 is more prone to bind to CerS4 and CerS2 to deplete lung and to enrich liver in d18:1/C20:0 and d18:1/C22:0 ceramides. It also interact with CerS1 to enrich liver in d18:1/C18:0 ceramides. Cer levels were counterbalanced by those of SM. In conclusion, these results demonstrate that the specificity of the effects of FB1 on tissues and organs is due to the effects of the toxin on CerS4, CerS2, and CerS1.

A comparative pathological finding in pigs exposed to fumonisin B1 and/or Mycoplasma hyopneumoniae

A more complicated pathology was observed in female pigs infected with Mycoplasma hyopneumoniae, when the same were exposed to 20 ppm dietary levels of fumonisin B1 (FB1) starting 14 days before infection for a period of 42 days as was assessed by gross pathology and pathomorphological examinations or computed tomography, and also manifested by the strong deterioration of the pneumonic process in two pigs and the subsequent euthanizing of one pig. Typical damages in FB1-fed pigs were a strong oedema in the lung and slight oedema in the other internal organs and mild degenerative changes in the kidneys, whereas the typical pathomorphological changes in M. hyopneumoniae-infected pigs corresponded to the morphologic pattern of a catarrhal bronchointerstitial pneumonia more pronounced in the cranial and middle lobes or in the cranial third of the caudal lobe of the lung. The pigs treated by both pathogens (toxic and infectious) revealed strong oedematous changes in the interstitium of lung in addition to deteriorated and extended bronchointerstitial pneumonic process.

The impact of Fusarium mycotoxins on human and animal host susceptibility to infectious diseases

Contamination of food and feed with mycotoxins is a worldwide problem. At present, acute mycotoxicosis caused by high doses is rare in humans and animals. Ingestion of low to moderate amounts of Fusarium mycotoxins is common and generally does not result in obvious intoxication. However, these low amounts may impair intestinal health, immune function and/or pathogen fitness, resulting in altered host pathogen interactions and thus a different outcome of infection. This review summarizes the current state of knowledge about the impact of Fusarium mycotoxin exposure on human and animal host susceptibility to infectious diseases. On the one hand, exposure to deoxynivalenol and other Fusarium mycotoxins generally exacerbates infections with parasites, bacteria and viruses across a wide range of animal host species. Well-known examples include coccidiosis in poultry, salmonellosis in pigs and mice, colibacillosis in pigs, necrotic enteritis in poultry, enteric septicemia of catfish, swine respiratory disease, aspergillosis in poultry and rabbits, reovirus infection in mice and Porcine Reproductive and Respiratory Syndrome Virus infection in pigs. However, on the other hand, T-2 toxin has been shown to markedly decrease the colonization capacity of Salmonella in the pig intestine. Although the impact of the exposure of humans to Fusarium toxins on infectious diseases is less well known, extrapolation from animal models suggests possible exacerbation of, for instance, colibacillosis and salmonellosis in humans, as well.

Biotransformation approaches to alleviate the effects induced by fusarium mycotoxins in swine

Mycotoxin mitigation is of major interest as ingestion of mycotoxins results in poor animal health, decreased productivity, as well as substantial economic losses. A feed additive (FA) consisting of a combination of bacteria (Eubacterium BBSH797) and enzyme (fumonisin esterase FumD) was tested in pigs for its ability to neutralize the effects of mono- and co-contaminated diets with deoxynivalenol (DON) and fumonisins (FB) on hematology, biochemistry, tissue morphology, and immune response. Forty-eight animals, allocated into eight groups, received one of eight diets for 35 days: a control diet, a diet contaminated with either DON (3 mg/kg) or FB (6 mg/kg), or both toxins, and the same four diets with FA. Inclusion of FA restored the circulating number of neutrophils of piglets fed the FB and DON + FB diets. Similarly, FA counteracted the minor changes observed on plasma concentrations of albumin and creatinine. In lung, the lesions induced by the ingestion of FB in mono- and co-contaminated diets were no longer observed after addition of FA in these diets. Lesions recorded in the liver of pigs fed either of the contaminated diets with FA were partly reduced, and the increased hepatocyte proliferation was totally neutralized when FA was present in the co-contaminated diet. After 35 days of exposure, the development of the vaccinal response was significantly improved in animals fed diets supplemented with FA, as shown by results of lymphocyte proliferation, cytokine expression in spleen, and the production of specific Ig. Similarly, in jejunum of animals fed diets with FA, occurrence of lesions and upregulation of pro-inflammatory cytokines were much less obvious. The ameliorative effects provided by FA suggest that this approach would be suitable in the control of DON and FB that commonly co-occur in feed.

Effect of low dose of fumonisins on pig health: immune status, intestinal microbiota and sensitivity to Salmonella

The objective of this study was to measure the effects of chronic exposure to fumonisins via the ingestion of feed containing naturally contaminated corn in growing pigs infected or not with Salmonella spp. This exposure to a moderate dietary concentration of fumonisins (11.8 ppm) was sufficient to induce a biological effect in pigs (Sa/So ratio), but no mortality or pathology was observed over 63 days of exposure. No mortality or related clinical signs, even in cases of inoculation with Salmonella (5 × 10⁴ CFU), were observed either. Fumonisins, at these concentrations, did not affect the ability of lymphocytes to proliferate in the presence of mitogens, but after seven days post-inoculation they led to inhibition of the ability of specific Salmonella lymphocytes to proliferate following exposure to a specific Salmonella antigen. However, the ingestion of fumonisins had no impact on Salmonella translocation or seroconversion in inoculated pigs. The inoculation of Salmonella did not affect faecal microbiota profiles, but exposure to moderate concentrations of fumonisins transiently affected the digestive microbiota balance. In cases of co-infection with fumonisins and Salmonella, the microbiota profiles were rapidly and clearly modified as early as 48 h post-Salmonella inoculation. Therefore under these experimental conditions, exposure to an average concentration of fumonisins in naturally contaminated feed had no effect on pig health but did affect the digestive microbiota balance, with Salmonella exposure amplifying this phenomenon.

Use of computed tomography and histopathologic review for lung lesions produced by the interaction between Mycoplasma hyopneumoniae and fumonisin mycotoxins in pigs

Mycoplasma hyopneumoniae has a primary role in the porcine respiratory disease complex (PRDC). The objective of this study was to determine whether fumonisin mycotoxins influence the character and/or the severity of pathological processes induced in the lungs of pigs by Mycoplasma hyopneumoniae. Four groups of pigs (n = 7/group) were used, one fed 20 ppm fumonisin B1 (FB1) from 16 days of age (group F), one only infected with M. hyopneumoniae on study day 30 (group M), and a group fed FB1 and infected with M. hyopneumoniae (group MF), along with an untreated control group (group C). Computed tomography (CT) scans of infected pigs (M and MF) on study day 44 demonstrated lesions extending to the cranial and middle or in the cranial third of the caudal lobe of the lungs. The CT images obtained on study day 58 showed similar but milder lesions in 5 animals from group M, whereas lungs from 2 pigs in group MF appeared progressively worse. The evolution of average pulmonary density calculated from combined pixel frequency values, as measured by quantitative CT, was significantly influenced by the treatment and the age of the animals. The most characteristic histopathologic lesion in FB1-treated pigs was pulmonary edema, whereas the pathomorphological changes in Mycoplasma-infected pigs were consistent with catarrhal bronchointerstitial pneumonia. FB1 aggravated the progression of infection, as demonstrated by severe illness requiring euthanasia observed in 1 pig and evidence of progressive pathology in 2 pigs (group MF) between study days 44 and 58.

The low intestinal and hepatic toxicity of hydrolyzed fumonisin B₁ correlates with its inability to alter the metabolism of sphingolipids

Fumonisins are mycotoxins frequently found as natural contaminants in maize, where they are produced by the plant pathogen Fusarium verticillioides. They are toxic to animals and exert their effects through mechanisms involving disruption of sphingolipid metabolism. Fumonisin B₁ (FB₁) is the predominant fumonisin in this family. FB₁ is converted to its hydrolyzed analogs HFB₁, by alkaline cooking (nixtamalization) or through enzymatic degradation. The toxicity of HFB₁ is poorly documented especially at the intestinal level. The objectives of this study were to compare the toxicity of HFB₁ and FB₁ and to assess the ability of these toxins to disrupt sphingolipids biosynthesis. HFB₁ was obtained by a deesterification of FB₁ with a carboxylesterase. Piglets, animals highly sensitive to FB₁, were exposed by gavage for 2 weeks to 2.8 μmol FB₁ or HFB₁/kg body weight/day. FB₁ induced hepatotoxicity as indicated by the lesion score, the level of several biochemical analytes and the expression of inflammatory cytokines. Similarly, FB₁ impaired the morphology of the different segments of the small intestine, reduced villi height and modified intestinal cytokine expression. By contrast, HFB₁ did not trigger hepatotoxicity, did not impair intestinal morphology and slightly modified the intestinal immune response. This low toxicity of HFB₁ correlates with a weak alteration of the sphinganine/sphingosine ratio in the liver and in the plasma. Taken together, these data demonstrate that HFB₁ does not cause intestinal or hepatic toxicity in the sensitive pig model and only slightly disrupts sphingolipids metabolism. This finding suggests that conversion to HFB₁ could be a good strategy to reduce FB₁ exposure.

Association of TLR4 polymorphism with cytokine expression level and pulmonary lesion score in pigs

The toll-like receptor 4 (TLR4), recognizing lipopolysaccharide of gram-negative bacteria, plays an essential role in immune responses. Variation in TLR4 alters host immune responses to pathogen and is associated with resistance/susceptibility to infectious diseases, as suggested by studies in humans and agricultural species, including cattle and chicken. In this study, we analyzed association of single nucleotide polymorphisms (SNPs) of TLR4 with cytokine expression level and pulmonary lesion score in swine. The SNP c.611 T>A showed significant association with the transcription levels of IFNG, TNFA, and IL-6 (P < 0.05); the SNP c.962 G>A showed significant association with the transcription of IFNG, IL-2, and IL-4 (P < 0.05); the SNP c.1,027 C>A showed significant association with the transcription of IFNG and IL-6 (P < 0.05); the haplotypes showed significant association with the transcription of IFNG, IL-2, IL-4, IL-6, and TNFA (P < 0.05). Both SNPs c.611 T>A and c.962 G>A showed significant association with pulmonary lesion scores (P < 0.01); and the combination genotypes of 3 polymorphic sites were also significantly associated with pulmonary lesion scores (P < 0.01). The observed relationship between TLR4 polymorphism and the transcription levels of cytokines indicate that these SNPs are related to the modulation of the cytokine mediated immune response.

Chronic ingestion of deoxynivalenol and fumonisin, alone or in interaction, induces morphological and immunological changes in the intestine of piglets

Deoxynivalenol (DON) and fumonisins (FB) are mycotoxins produced by Fusarium species, which naturally co-occur in animal diets. The gastrointestinal tract represents the first barrier met by exogenous food/feed compounds. The purpose of the present study was to investigate the effects of DON and FB, alone and in combination, on some intestinal parameters, including morphology, histology, expression of cytokines and junction proteins. A total of twenty-four 5-week-old piglets were randomly assigned to four different groups, receiving separate diets for 5 weeks: a control diet; a diet contaminated with either DON (3 mg/kg) or FB (6 mg/kg); or both toxins. Chronic ingestion of these contaminated diets induced morphological and histological changes, as shown by the atrophy and fusion of villi, the decreased villi height and cell proliferation in the jejunum, and by the reduced number of goblet cells and lymphocytes. At the end of the experiment, the expression levels of several cytokines were measured by RT-PCR and some of them (TNF-α, IL-1β, IFN-γ, IL-6 and IL-10) were significantly up-regulated in the ileum or the jejunum. In addition, the ingestion of contaminated diets reduced the expression of the adherent junction protein E-cadherin and the tight junction protein occludin in the intestine. When animals were fed with a co-contaminated diet (DON+FB), several types of interactions were observed depending on the parameters and segments assessed: synergistic (immune cells); additive (cytokines and junction protein expression); less than additive (histological lesions and cytokine expression); antagonistic (immune cells and cytokine expression). Taken together, the present data provide strong evidence that chronic ingestion of low doses of mycotoxins alters the intestine, and thus may predispose animals to infections by enteric pathogens.

Real and perceived risks for mycotoxin contamination in foods and feeds: challenges for food safety control

Mycotoxins are toxic compounds, produced by the secondary metabolism of toxigenic moulds in the Aspergillus, Alternaria, Claviceps, Fusarium, Penicillium and Stachybotrys genera occurring in food and feed commodities both pre- and post-harvest. Adverse human health effects from the consumption of mycotoxins have occurred for many centuries. When ingested, mycotoxins may cause a mycotoxicosis which can result in an acute or chronic disease episode. Chronic conditions have a much greater impact, numerically, on human health in general, and induce diverse and powerful toxic effects in test systems: some are carcinogenic, mutagenic, teratogenic, estrogenic, hemorrhagic, immunotoxic, nephrotoxic, hepatotoxic, dermotoxic and neurotoxic. Although mycotoxin contamination of agricultural products still occurs in the developed world, the application of modern agricultural practices and the presence of a legislatively regulated food processing and marketing system have greatly reduced mycotoxin exposure in these populations. However, in developing countries, where climatic and crop storage conditions are frequently conducive to fungal growth and mycotoxin production, much of the population relies on subsistence farming or on unregulated local markets. Therefore both producers and governmental control authorities are directing their efforts toward the implementation of a correct and reliable evaluation of the real status of contamination of a lot of food commodity and, consequently, of the impact of mycotoxins on human and animal health.

Exposure of infants to fumonisins in maize-based complementary foods in rural Tanzania

Feeding children with maize may expose them to fumonisins (FBs). This study assessed FB exposure for infants consuming maize in Tanzania by modeling maize consumption data (kg/kg body weight (bw)/day) with previously collected total FB contamination (microg/kg) patterns for sorted and unsorted maize harvested in 2005 and 2006. Consumption was estimated by twice conducting a 24 h dietary recall for 254 infants. The exposure assessment was performed with the @RISK analysis software. Of the infants, 89% consumed maize from 2.37 to 158 g/person/day (mean; 43 g/person/day +/- 28). Based on the contamination for sorted maize; in 2005, the percentage of infants with FB exposures above the provisional maximum tolerable daily intake (PMTDI) of 2 microg/kg (bw) (26% (95% confidence interval (CI); 23-30)) was significantly higher than the level of 3% (90% CI; 2-12) in 2006. Pooling the datasets for sorted maize from the two seasons resulted in a seemingly more representative risk (10% (95% CI; 6-17)) of exceeding the PMTDI. However, infants who might have consumed unsorted maize would still be at a significantly higher risk (24% (95% CI; 15-34)) of exceeding the PMTDI. Sorting and other good maize management practices should be advocated to farmers in order to minimize FB exposure in rural areas.

A review of the toxic effects and mechanisms of action of fumonisin B1

Fumonisin B(1) (FB(1)) is a mycotoxin produced by the fungus Fusarium verticillioides, which commonly infects corn and other agricultural products. Fusarium species can also be found in moisture-damaged buildings, and, therefore, exposure of humans to Fusarium mycotoxins including FB(1) may take place. FB(1) bears a clear structural similarity to the cellular sphingolipids, and this similarity has been shown to disturb the metabolism of sphingolipids by inhibiting the enzyme ceramide synthase leading to accumulation of sphinganine in cells and tissues. FB(1) is neurotoxic, hepatotoxic, and nephrotoxic in animals, and it has been classified as a possible carcinogen to humans. The cellular mechanisms behind FB(1)-induced toxicity include the induction of oxidative stress, apoptosis, and cytotoxicity, as well as alterations in cytokine expression. The effects of FB(1) on different parameters vary markedly depending on what types of cells are studied or what species they originate from. These aspects are important to consider when evaluating the toxic potential of FB(1).

Effect of Fusarium verticillioides extract on specific antibody production against Paracoccidioides brasiliensis

The aim of this study was to evaluate the effect of partially purified Fusarium verticillioides fumonisins (FB) on the specific humoral response in mice infected with Paracoccidioides brasiliensis (Pb), the agent of paracoccidioidomycosis (PCM). Four groups of male Swiss mice were used (total 44 mice): infected (Pb), treated (FB), infected and treated (Pb/FB) and uninfected and untreated (PBS). Groups Pb and Pb/FB were inoculated i.v. with 1x105 Pb yeast cells (strain Pb18) and, after 28 days, groups FB and Pb/FB were inoculated (s.c.) with partially purified FB from F. verticillioides (5x2.25 mg FB/kg body weight). After 7 days, the plasma levels of total IgG and anti-gp43 IgG (specific antibody) were analysed by immunoenzyme assay (ELISA). The total IgG level was higher in groups Pb, FB and Pb/FB than in PBS (P<0.05) and the anti-gp43 IgG level was raised in groups Pb and Pb/FB, but a significant result was obtained only in Pb/FB, relative to the other groups (P<0.05). In conclusion, FB or other components of F. verticillioides extracts significantly increase the specific antibody response in male Swiss mice infected with Pb.

Ingestion of deoxynivalenol (DON) contaminated feed alters the pig vaccinal immune responses

Deoxynivalenol (DON), a mycotoxin produced by some Fusarium species, is a frequent contaminant of cereals. This toxin is known to modulate the immune function but only few studies have investigated the effect of DON on the vaccinal immune response. In the present experiment, 24 pigs received for 9 weeks either control feed or feed naturally contaminated with 2.2-2.5 mgDON/kg feed. At days 4 and 15 of the experiment, the animals were subcutaneously immunized with ovalbumin. Consumption of DON-contaminated diet does not have a major effect on the hematological and biochemical blood parameters. By contrast, ingestion of DON significantly affects the global and the specific immune response of the pigs. In the serum, DON increases the concentration of total IgA and, in vaccinated animals, DON also increases the concentration of ovalbumin-specific IgA and IgG. DON does not modulate lymphocytes proliferation after mitogenic stimulation but the toxin had a biphasic effect on lymphocyte proliferation after antigenic stimulation (up-regulation at day 21 and down-regulation at day 35-49). Because cytokines play a key role in immunity, the expression levels of TGF-beta, IFN-gamma, IL-4 and IL-6 were measured, by RT-PCR in the spleen, the ileum and the mesenteric lymph node of the animals at the end of the experiment. In the mesenteric lymph node, a significantly lower expression of both TGF-beta and IFN-gamma mRNA expression levels is observed in animals feed with DON when compared with control piglets. Taken together, our data indicate that DON alters the vaccinal immune response. These results may have implications for humans and animals consuming DON-contaminated food or feed as breakdown in vaccinal immunity may lead to the occurrence of disease even in properly vaccinated populations.

The intestine as a possible target for fumonisin toxicity

Fumonisins constitute a family of toxic and carcinogenic mycotoxins produced by Fusarium verticillioides (formerly F. moniliforme), a common fungal contaminant of corn. Contamination with fumonisin B(1) (FB(1)) is of concern as this mycotoxin causes various animal diseases. The gastrointestinal tract represents the first barrier against ingested chemicals, food contaminants, and natural toxins. Following ingestion of fumonisin-contaminated food or feed, intestinal epithelial cells could be exposed to a high concentration of toxin. In this review, we have summarized the data dealing with the impact of FB(1) on the intestine. Although FB(1 )is poorly absorbed and metabolized in the intestine, it induces intestinal disturbances (abdominal pain or diarrhea) and causes extra-intestinal organ pathologies (pulmonary edema, leukoencephalomalacia, or neural tube defects). The main toxicological effect of FB(1) reported in vivo and in vitro is the accumulation of sphingoid bases associated with the depletion of complex sphingolipids. This disturbance of the sphingolipid biosynthesis pathway could explain the other observed toxicological effects such as an alteration in intestinal epithelial cell viability and proliferation, a modification of cytokine production, and a modulation of intestinal physical barrier function.

Mycotoxin fumonisin B1 selectively down-regulates the basal IL-8 expression in pig intestine: in vivo and in vitro studies

Fumonisin B(1) (FB(1)) is a mycotoxin produced by Fusarium verticillioides and F. proliferatum, common contaminants of maize. FB(1) causes toxicological effects in laboratory and domestic animals including pigs. The gastrointestinal tract represents a barrier encountered by exogenous food compounds. The purpose of our study was to determine FB(1) effects on intestinal immune response. Nine recently weaned piglets orally received 0.5 mg of purified toxin/kg of body weight/day for 7 days, while eight other animals were kept as controls. After necropsy, ileal samples were analyzed for five pro-inflammatory cytokines mRNA expression by RT-PCR. No difference was observed for IL-1beta, IL-6, IL-12 and TNF-beta mRNA levels between control and FB(1)-treated animals. In contrast, FB(1) treatment induced a significant down-regulation of the expression of IL-8 mRNA in the pig ilea. The effect of FB(1) on the IL-8 expression was also examined in the porcine intestinal epithelial cell line IPEC-1. FB(1) decreases the expression of IL-8, both at the mRNA and protein levels, in a dose-dependant manner. Taken together, our data demonstrate that FB(1) alters the intestinal immune response by decreasing the level of IL-8. This may contribute to the increased intestinal colonization by pathogenic Escherichia coli that was observed in FB(1)-treated pigs and may have implications for humans/animals consuming FB(1)-contaminated food/feed.

Sex-related differences in the immune response of weanling piglets exposed to low doses of fumonisin extract

Fumonisin B1 (FB1) is a mycotoxin produced by Fusarium verticillioides, a fungus that commonly contaminates maize. Sex-related effects of FB1 have been observed with respect to carcinogenicity in rodents, to performances in pigs and immunosuppression in mice. In the present study the sex-related effect of FB1 on the pig immune response was determined. Female and castrated male piglets received for 28 d either control feed or feed contaminated with 8 mg FB1/kg feed in the form of F. verticillioides culture material. At day 7 and day 21, animals were immunised subcutaneously with a Mycoplasma agalactiae vaccine. Ingestion of FB1-contaminated feed significantly decreased weight gain in males but had no effect in females. No sex-related difference was observed in biochemical parameters, but a higher level of creatinine was noted in toxin-treated animals. FB1 also altered the pig immune response in a sex-specific manner. In males, ingestion of FB1-contaminated feed significantly decreased specific antibody levels after vaccination as well as the mRNA expression level of IL-10. In females, the toxin has no effect on specific antibodies or on cytokine mRNA levels. The results of the present study indicate that FB1 is immunosuppressive in pigs. The magnitude of this FB1-induced immunosuppression is highly dependent on sex, with males being more susceptible than females.

Ingestion of low doses of deoxynivalenol does not affect hematological, biochemical, or immune responses of piglets1

Deoxynivalenol (DON), a mycotoxin produced by Fusarium spp., is a frequent contaminant of cereals. Because of their rich cereal diet, pigs could be exposed to this mycotoxin. Pigs are among the animal species showing the greatest sensitivity to DON. Effects of intermediate to high levels of DON on pigs are well known and include feed refusal, decreased feed intake, and alteration of the immune response. Effects of low levels of DON, which are commonly detected in contaminated feed, remain unknown. The aim of this study was to investigate the effect of a diet naturally contaminated with a low concentration of DON (0, 280, 560, or 840 microg/kg of feed) on performance of weanling piglets and on 34 hematological, biochemical, and immune variables. Low doses of DON did not alter the animal performances (feed intake and BW gain). Such low levels of DON did not modify the 9 hematological variables measured (including white blood cell, red blood cell, and platelet counts, relative numbers of neutrophils and lymphocytes, and hematocrit and hemoglobin concentrations) or the 18 biochemical variables tested (including cations, glucose, urea, creatinine, bilirubin, cholesterol and triglyceride concentrations, and plasma enzyme activity). Similarly, no effect of low doses of DON was observed on the immune responses of the animals (immunoglobulin subset concentration, lymphocyte proliferation, and cytokine production).