Report of the 1st International Electronic Conference on Toxins (IECT2021), 16-31 January 2021.

The 1st International Electronic Conference on Toxins (IECT2021) was successfully held online by https://sciforum [...].

Hunted game birds - Carriers of foodborne pathogens.

Game birds may carry zoonotic bacteria in their intestines and transmit them to hunters through bird handling or through the handling and consumption of contaminated meat. In this study, the prevalence of foodborne bacteria was screened from game bird faeces and mallard breast meat using PCR. The sampling occurred in southern Finland from August to December during the hunting season. Isolates were characterized by multi-locus sequence typing. Mesophilic aerobic bacteria and Escherichia coli counts were used to assess the microbial contamination of mallard meat. In total, 100 woodpigeon (Columba palumbus), 101 pheasants (Phasianus colchicus), 110 mallards (Anas platyrhynchos), and 30 teals (Anas crecca) were screened during the hunting season. Additionally, 100 mallard breast meat samples were collected. Campylobacter and Listeria were commonly detected in the faeces and Listeria on mallard meat. L. monocytogenes of sequence types associated with human listeriosis were frequently found in game bird faeces and on mallard meat. Good hygiene during game bird handling, storing the game bird meat frozen, and proper heat treatment are important measures to minimize the health risk for hunters and consumers.

Trichothecenes in Food and Feed, Relevance to Human and Animal Health and Methods of Detection: A Systematic Review.

Trichothecene mycotoxins are sesquiterpenoid compounds primarily produced by fungi in taxonomical genera such as Fusarium, Myrothecium, Stachybotrys, Trichothecium, and others, under specific climatic conditions on a worldwide basis. Fusarium mold is a major plant pathogen and produces a number of trichothecene mycotoxins including deoxynivalenol (or vomitoxin), nivalenol, diacetoxyscirpenol, and T-2 toxin, HT-2 toxin. Monogastrics are sensitive to vomitoxin, while poultry and ruminants appear to be less sensitive to some trichothecenes through microbial metabolism of trichothecenes in the gastrointestinal tract. Trichothecene mycotoxins occur worldwide however both total concentrations and the particular mix of toxins present vary with environmental conditions. Proper agricultural practices such as avoiding late harvests, removing overwintered stubble from fields, and avoiding a corn/wheat rotation that favors Fusarium growth in residue can reduce trichothecene contamination of grains. Due to the vague nature of toxic effects attributed to low concentrations of trichothecenes, a solid link between low level exposure and a specific trichothecene is difficult to establish. Multiple factors, such as nutrition, management, and environmental conditions impact animal health and need to be evaluated with the knowledge of the mycotoxin and concentrations known to cause adverse health effects. Future research evaluating the impact of low-level exposure on livestock may clarify the potential impact on immunity. Trichothecenes are rapidly excreted from animals, and residues in edible tissues, milk, or eggs are likely negligible. In chronic exposures to trichothecenes, once the contaminated feed is removed and exposure stopped, animals generally have an excellent prognosis for recovery. This review shows the occurrence of trichothecenes in food and feed in 2011-2020 and their toxic effects and provides a summary of the discussions on the potential public health concerns specifically related to trichothecenes residues in foods associated with the exposure of farm animals to mycotoxin-contaminated feeds and impact to human health. Moreover, the article discusses the methods of their detection.

Biogenic amines: formation, action and toxicity - a review.

Biogenic amines (BA) are organic compounds commonly found in food, plants and animals, as well as microorganisms that are attributed with the production of BAs. They are formed as an effect of a chemical process: the decarboxylation of amino acids. Factors determining the formation of BAs include the availability of free amino acids and the presence of microorganisms that show activity with respect to carrying out the decarboxylation process. On the one hand, BAs are compounds that are crucial for maintaining cell viability, as well as the proper course of the organism's metabolic processes, such as protein synthesis, hormone synthesis and DNA replication. On the other hand, despite their positive effects on the functioning of the organism, an excessive content of BAs proves to be toxic (diarrhea, food poisoning, vomiting, sweating or tachycardia). Moreover, they can accelerate carcinogenesis. Amines are a natural component of plant and animal raw materials. As a result of the proven negative effects of amines on living organisms, the reduction of these compounds should be the subject of scientific research. The present review aims to synthesize and summarize the information currently available on BAs, as well as discuss the interpretation of the results. © 2020 Society of Chemical Industry.

Interactions between Food Hazards and Intestinal Barrier: Impact on Foodborne Diseases.

The intestine is an important digestive organ of the human body, and its barrier is the guardian of the body from the external environment. The impairment of the intestinal barrier is believed to be an important determinant in various foodborne diseases. Food hazards can lead to the occurrence of many foodborne diseases represented by inflammation. Therefore, understanding the mechanisms of the impact of the food hazards on intestinal barriers is essential for promoting human health. This review examined the relationship between food hazards and the intestinal barrier in three aspects: apoptosis, imbalance of gut microbiota, and pro-inflammatory cytokines. The mechanism of dysfunctional gut microbiota caused by food hazards was also discussed. This review discusses the interaction among food hazards, intestinal barrier, and foodborne diseases and, thus, offers a new thought to deal with foodborne disease.

The Bacillus cereus Food Infection as Multifactorial Process.

The ubiquitous soil bacterium Bacillus cereus presents major challenges to food safety. It is responsible for two types of food poisoning, the emetic form due to food intoxication and the diarrheal form emerging from food infections with enteropathogenic strains, also known as toxico-infections, which are the subject of this review. The diarrheal type of food poisoning emerges after production of enterotoxins by viable bacteria in the human intestine. Basically, the manifestation of the disease is, however, the result of a multifactorial process, including B. cereus prevalence and survival in different foods, survival of the stomach passage, spore germination, motility, adhesion, and finally enterotoxin production in the intestine. Moreover, all of these processes are influenced by the consumed foodstuffs as well as the intestinal microbiota which have, therefore, to be considered for a reliable prediction of the hazardous potential of contaminated foods. Current knowledge regarding these single aspects is summarized in this review aiming for risk-oriented diagnostics for enteropathogenic B. cereus.

Gastric Ulceration and Immune Suppression in Weaned Piglets Associated with Feed-Borne Bacillus cereus and Aspergillus fumigatus.

As a multifactorial cause, gastric ulceration-mediated diarrhea is widely prevalent in the weaned piglets, impairing pig health and economic benefits. With full implementation of antibiotic stewardship programs in China, Bacillus cereus (B. cereus) and Aspergillus fumigatus (A. fumigatus) were identified frequently in porcine feedstuffs and feeds of the animal industry. Association between feed-borne B. cereus and frequent diarrhea remains unclear. In the present study, we conducted a survey of B. cereus and A. fumigatus from feeds and feedstuffs in pig farms during hot season. Interestingly, B. cereus, B. subtilis, B. licheniformis and B. thuringinesis were isolated and identified from piglets' starter meals to sow feeds, accounting for 56.1%, 23.7%, 13.7% and 6.5%, respectively. Obviously, both B. cereus and B. subtili were dominant contaminants in the survey. In an in vitro study, Deoxynivalenol (DON) contents were determined in a dose-dependent manner post fermentation with B. cereus (405 and DawuC). Subsequently, 36 weaned piglets were randomly assigned to four groups and the piglets simultaneously received the combination of virulent B. cereus (Dawu C) and A. fumigatus while animals were inoculated with B. cereus (Dawu C), A. fumigatus or PBS as the control group. Clinically, piglets developed yellow diarrhea on day 5 and significant reductions of relative body weight were observed in the B. cereus group, and co-infection group. More importantly, IgG titers against Classical swine fever virus (CSFV) and Porcine epidemic diarrhea (PED) were reduced dramatically during 14-day observation in co-infection group, the B. cereus (Dawu C) group or the A. fumigatus group. However, lower Foot and mouth disease (FMD) -specific antibodies were reduced on day 7 compared to those of the control group. Additionally, lower lymphocyte proliferations were found in the B. cereus group and the co-infection group compared to the control group. Postmortem, higher lesions of gastric ulceration were observed in the B. cereus group and the co-infection group from day 7 to day 14 compared with those of the A. fumigatus group and the control group. Compared to the A. fumigatus group, higher DON contents were detected in the stomach inoculated with B. cereus and the co-infection with A. fumigatus. In conclusion, our data support the hypothesis that B. cereus might be associated with severe diarrhea by inducing gastric ulcerations and A. fumigatus might aggravate immune suppression, threating a sustainable swine industry. It is urgently needed to control feed-borne B. cereus contamination.

Mucosal CD8 T Cell Responses Are Shaped by Batf3-DC After Foodborne Listeria monocytogenes Infection.

While immune responses have been rigorously examined after intravenous Listeria monocytogenes (Lm) infection, less is understood about its dissemination from the intestines or the induction of adaptive immunity after more physiologic models of foodborne infection. Consequently, this study focused on early events in the intestinal mucosa and draining mesenteric lymph nodes (MLN) using foodborne infection of mice with Lm modified to invade murine intestinal epithelium (InlAMLm). InlAMLm trafficked intracellularly from the intestines to the MLN and were associated with Batf3-independent dendritic cells (DC) in the lymphatics. Consistent with this, InlAMLm initially disseminated from the gut to the MLN normally in Batf3-/- mice. Activated migratory DC accumulated in the MLN by 3 days post-infection and surrounded foci of InlAMLm. At this time Batf3-/- mice displayed reduced InlAMLm burdens, implicating cDC1 in maximal bacterial accumulation in the MLN. Batf3-/- mice also exhibited profound defects in the induction and gut-homing of InlAMLm-specific effector CD8 T cells. Restoration of pathogen burden did not rescue antigen-specific CD8 T cell responses in Batf3-/- mice, indicating a critical role for Batf3 in generating anti-InlAMLm immunity following foodborne infection. Collectively, these data suggest that DC play diverse, dynamic roles in the early events following foodborne InlAMLm infection and in driving the establishment of intestinal Lm-specific effector T cells.

Glucose-regulated protein 75 in foodborne disease models induces renal tubular necrosis.

The incidence of kidney disease has increased rapidly in recent years. One major possible reason for this increase in nephrosis is from foodborne toxins. Since the mechanism of how foodborne toxins are involved in the process of nephrosis is largely unknown, the current study aims to establish a profile for how one of the major toxin threats, ochratoxin A (OTA), induce differential protein expression. In this proteomic study of rat kidneys, 75 kd glucose-regulated protein (Grp75) expression was found to be sensitized by a low concentration of OTA, but inhibited by high doses. In response to OTA, a decrease in Grp75 expression preceded the inhibition of mitochondrial Lon peptidase 1 (Lonp1). Using Grp75 knockdown cell line, it was shown that the inhibition of Grp75 promoted the secretion of kidney injury molecule 1 (Kim1), and suppressed Lonp1 expression in renal injury. Moreover, the acceleration of renal disease was associated with the consumption of Grp75. Our study suggests that the Grp75 protein may be valuable as both a treatment and biomarker for the foodborne diseases that induce renal tubular necrosis. The findings of this research are beneficial for the establishment of nutritional interventions, and the screening of therapeutic targets, in cases of nephrosis.

Oral administration of oxalate-enriched spinach extract as an improved methodology for the induction of dietary hyperoxaluric nephrocalcinosis in experimental rats.

Experimental induction of hyperoxaluria by ethylene glycol (EG) administration is disapproved as it causes metabolic acidosis while the oral administration of chemically synthesized potassium oxalate (KOx) diet does not mimic our natural system. Since existing models comprise limitations, this study is aimed to develop an improved model for the induction of dietary hyperoxaluria, and nephrocalcinosis in experimental rats by administration of naturally available oxalate rich diet. Male albino Wistar rats were divided into five groups. Group I, control; group II rats received 0.75% EG, group III rats fed with 5% KOx diet and group IV and V rats were administered with spinach extract of 250 and 500 mg soluble oxalate/day respectively, for 28 d. Urine and serum biochemistry were analyzed. After the experimental period, rats were sacrificed, liver and kidney tissue homogenates were used for antioxidant and lipid peroxidation assay. Relative change in expression of kidney injury molecule-1 (KIM-1) and crystal modulators genes in kidney tissues were evaluated. Tissue damage was assessed by histology studies of liver and kidney. Experimental group rats developed hyperoxaluria and crystalluria. Urine parameters, serum biochemistry, antioxidant profile, lipid peroxidation levels and gene expression analysis of experimental group II and III rats reflected acute kidney damage compared to group V rats. Histopathology results showed moderate hyperplasia in liver and severe interstitial inflammation in kidneys of group II and III than group V rats. Ingestion of naturally available oxalate enriched spinach extract successfully induced dietary hyperoxaluria and nephrocalcinosis in rats with minimal kidney damage.

Assessment of deoxynivalenol exposure among Bangladeshi and German adults by a biomarker-based approach.

Deoxynivalenol (DON) is a frequent mycotoxin contaminant in cereal crops worldwide and can cause adverse health effects in exposed animals and humans. Since DON contamination in Bangladeshi food is unexplored, we conducted a biomonitoring study to assess DON exposure in the Bangladeshi population and compare it with that of German adults. In total 214 urines were collected, n=164 in Bangladesh and n=50 in Germany. In Bangladesh rural and urban residents of Rajshahi district provided urines in two seasons (n=69 in summer, n=95 in winter, with 62 participants enrolled in both periods). Urinary DON and its de-epoxy metabolite DOM-1 were measured by a previously validated sensitive LC-MS/MS method. In Bangladeshi urines, DON was detectable in 27% (range 0.16-1.78ng/mL) in summer and 31% (range 0.16-1.21ng/mL) in winter season. There was no significant difference at the mean DON level between season (summer 0.17±0.25ng/mL and winter 0.16±0.18ng/mL) and region (rural or urban residents). The metabolite DOM-1 was not detected in any urine from Bangladesh. In contrast, DON and DOM-1 were detected in 100% (range 0.16-38.44ng/mL) and 40% (range 0.10-0.73ng/mL), respectively, of the German urines. The mean DON level in German urines (9.02±6.84ng/mL) was about 53-fold higher than that found in Bangladeshi samples. This indicates a low and high dietary DON exposure among the adult population in Bangladesh and Germany, respectively. The biomarker concentrations found and published urinary excretion rates for DON then served to calculate the daily mycotoxin intake in both cohorts: the mean DON intake in Bangladesh being 6ng/kg b.w., and in Germany a mean of 268 and maximum intake of 975ng/kg b.w., values lower than the provisional maximum tolerable daily intake of 1µg/kg b.w. set by the WHO/JECFA.

Scombroid Poisoning: A Practical Approach. / Escombroidosis: abordaje práctico.

Scombroid poisoning is a common cause of food poisoning worldwide. It is caused by ingestion of oily fish contaminated with bacteria that trigger the formation of high concentrations of histamine. Scombroid poisoning manifests mainly as a skin complaint (flushing that spreads downward and/or an erythematous urticarial rash affecting the face and upper trunk). Although the clinical course is usually self-limiting and benign, vascular compromise, bronchospasm, and arrhythmias have been described. It is important to establish a differential diagnosis that includes conditions such as fish allergy. Oral antihistamines are the mainstay of treatment. Scombroid poisoning is best prevented by refrigerating fish properly. The practical review of scombroid poisoning provided here is intended for dermatologists.

[The study of influence of stresses on virulence genes expression in foodborne pathogens Campylobacter jejuni].

The study of the responses to cold exposure in Campylobacterjejuni (C. jejuni)--one of the most common foodborne pathogens is important for elucidating the mechanisms of acquisition of products contaminated with campylobacter, hazardous properties. These data are also necessary to create effective systems of microbiological controls at all stages of production and storage of food. 5 pairs of oligonucleotide primers were selected for detecting of genes cadF, cdtB, ciaB, flaA, iamA, encoding the main factors of pathogenicity of foodborne pathogens Campylobacter jejuni--adhesion and invasion of epithelial cells, production of CDT-toxin and mobility. To quantify the expression levels of target genes of C. jejuni a comparative method of determining the amount of amplification products of genes encoding pathogenicity factors of Campylobacter spp. has been developed using real-time PCR with intercalating dyes. To calculate and quantify gene expression the mathematical models have been obtained that allow extrapolation of threshold cycles of amplification to the initial number of copies of RNA/DNA in the tested samples. It has been established that exposure of C. jejuni at low temperatures +4 degrees C did not lead to increased levels of expression of genes cdtB and ciaB. However, in the populations of C. jejuni subjected to freezing, followed by incubation at optimum for the pathogen temperature of +42 degrees C, the increase in expression of mRNA encoding protein subunit B of CDT-toxin and antigenic marker of invasion took place. The number of copies of RNA in C. jejuni after stress exposure increased by 1.14-2.6 lg in comparison with intact cultures. CdtB and ciaB gene expression in C. jejuni can serve as an indicator of cell response to stress and helps to restore the functions of the bacterial cells after the termination of cold exposure and return of the pathogen in conditions favourable to the realization of its pathogenic potential.

Histamine, histamine intoxication and intolerance.

Excessive accumulation of histamine in the body leads to miscellaneous symptoms mediated by its bond to corresponding receptors (H1-H4). Increased concentration of histamine in blood can occur in healthy individuals after ingestion of foods with high contents of histamine, leading to histamine intoxication. In individuals with histamine intolerance (HIT) ingestion of food with normal contents of histamine causes histamine-mediated symptoms. HIT is a pathological process, in which the enzymatic activity of histamine-degrading enzymes is decreased or inhibited and they are insufficient to inactivate histamine from food and to prevent its passage to blood-stream. Diagnosis of HIT is difficult. Multi-faced, non-specific clinical symptoms provoked by certain kinds of foods, beverages and drugs are often attributed to different diseases, such as allergy and food intolerance, mastocytosis, psychosomatic diseases, anorexia nervosa or adverse drug reactions. Correct diagnosis of HIT followed by therapy based on histamine-free diet and supplementation of diamine oxidase can improve patient's quality of life.

Invited review: Diagnosis of zearalenone (ZEN) exposure of farm animals and transfer of its residues into edible tissues (carry over).

The aim of the review was to evaluate the opportunities for diagnosing the zearalenone (ZEN) exposure and intoxication of farm animals by analyzing biological specimens for ZEN residue levels. Metabolism is discussed to be important when evaluating species-specific consequences for the overall toxicity of ZEN. Besides these toxicological facts, analytics of ZEN residues in various animal-derived matrices requires sensitive, matrix-adapted multi-methods with low limits of quantification, which is more challenging than the ZEN analysis in feed. Based on dose-response experiments with farm animals, the principle usability of various specimens as bio-indicators for ZEN exposure is discussed with regard to individual variation and practicability for the veterinary practitioner. ZEN residue analysis in biological samples does not only enable evaluation of ZEN exposure but also allows the risk for the consumer arising from contaminated foodstuffs of animal origin to be assessed. It was compiled from literature that the tolerable daily intake of 0.25 µg ZEN/kg body weight and day is exploited to approximately 8%, when a daily basket of animal foodstuffs and associated carry over factors are assumed at reported ZEN contamination levels of complete feed.

Decrease in pyridoxal-5'-phosphate concentration and increase in pyridoxal concentration in rat plasma by 4'-O-methylpyridoxine administration.

Food poisoning from Ginkgo biloba seeds can cause epilepsy because of a decrease in γ-aminobutyric acid (GABA) concentrations in the brain. We previously demonstrated that 4'-O-methylpyridoxine (MPN) is responsible for this observed toxicity of G biloba seeds; however, the mechanism for the decrease in GABA and plasma concentration profile of MPN has not been clarified. Our hypothesis is that MPN induces a decrease in vitamin B6 concentrations, resulting in a decrease in GABA concentration. This study aimed to characterize the plasma concentration profile of MPN and intrinsic vitamin B6 concentrations (pyridoxal [PL], PL-5'-phosphate [PLP], and 4-pyridoxic acid) using a rat model. Plasma concentrations of B6 vitamers after intravenous MPN administration (5 mg/kg) were determined using high-performance liquid chromatography with a fluorescence detector. The half-life of MPN (0.91 ± 0.05 hours) was shorter in rats than the previously reported value in humans. We found a significant decrease in the plasma concentration of PLP, an active form of vitamin B6, after MPN administration. We also observed an increase in plasma PL and 4-pyridoxic acid concentrations; the increase in PL concentration may be caused by either metabolism of MPN to PL or by MPN-mediated inhibition of PL kinase. The present study is the first in vivo study showing relatively rapid elimination of MPN in rats and a decrease in plasma PLP concentration caused by MPN.

Selenium and Iodine in Autoimmune Thyroiditis.

Selenium and iodine are essential for thyroid hormone synthesis and function. Selenium, in form of selenocysteine, is found either in the catalytic center of enzymes involved in the protection of the thyroid gland from free radicals originating during thyroid hormone synthesis, and in three different iodothyronine deiodinases catalyzing the activation and the inactivation of thyroid hormones. Iodine is an essential constituent of thyroid hormones and its deficiency causes different disorders that include goiter, hypothyroidism, reduced fertility and alteration in growth, physical and neurological development. These two micronutrients could be involved in the pathogenesis of autoimmune thyroid diseases, a spectrum of pathological conditions including Hashimoto's thryoiditis, post-partum thyroiditis, the so-called painless thyroiditis, Graves' disease and Graves' ophtalmopathy. Aim of this paper is to review the role played by selenium and iodine in autoimmune thyroiditis.

Heliotropium europaeum poisoning in cattle and analysis of its pyrrolizidine alkaloid profile.

Pyrrolizidine alkaloids (PAs) are carcinogenic and genotoxic phytochemicals found exclusively in angiosperms. The ingestion of PA-containing plants often results in acute and chronic toxicities in man and livestock, targeting mainly the liver. During February 2014, a herd of 15-18-month-old mixed-breed beef cattle (n = 73) from the Galilee region in Israel was accidently fed hay contaminated with 12% Heliotropium europaeum (average total PA intake was 33 mg PA/kg body weight/d). After 42 d of feed ingestion, sudden death occurred over a time period of 63 d with a mortality rate of 33%. Necropsy and histopathological examination revealed fibrotic livers and moderate ascites, as well as various degrees of hyperplasia and fibrosis of bile duct epithelial cells. Elevated γ-glutamyl-transferase and alkaline phosphatase levels were indicative of severe liver damage. Comprehensive PA profile determination of the contaminated hay and of native H. europaeum by LC-MS/MS revealed the presence of 30 PAs and PA-N-oxides, including several newly reported PAs and PA-N-oxides of the rinderine and heliosupine class. Heliotrine- and lasiocarpine-type PAs constituted 80% and 18% of the total PAs, respectively, with the N-oxides being the most abundant form (92%). The PA profile of the contaminated hay showed very strong resemblance to that of H. europaeum.

Impacts of the feed contaminant deoxynivalenol on the intestine of monogastric animals: poultry and swine.

Deoxynivalenol (DON) is one of the most prevalent cereal contaminants with major public health concerns owing to its high toxigenic potentials. Once ingested, DON first and foremost targets epithelial cells of the gastrointestinal tract, whose proper functioning, as the first line of defence, is of paramount importance for the host's health. Emerging evidences, summarized in this article, suggest that DON produces its toxicity primarily via activation of the mitogen-activated protein kinases (MAPKs) signalling pathway and alteration in the expression of genes responsible for key physiological and immunological functions of the intestinal tissue of chickens and pigs. The activation of MAPKs signalling cascade results in disruption of the gut barrier function and an increase in the permeability by reducing expression of the tight junction proteins. Exposure to DON also down-regulates the expression of multiple transporter systems in the enterocytes with subsequent impairment of the absorption of key nutrients. Other major intestinal cytotoxic effects of DON described herein are modulation of mucosal immune responses, leading to immunosupression or stimulation of local immune cells and cytokine release, and also facilitation of the persistence of intestinal pathogens in the gut. Both of the last events potentiate enteric infections and local inflammation in pigs and poultry, rendering enterocytes and the host more vulnerable to luminal toxic compounds. This review highlights the cytotoxic risks associated with the intake of even low levels of DON and also identifies gaps of knowledge that need to be addressed by future research.