Fecal transplantation of young mouse donors effectively improves enterotoxicity in elderly recipients exposed to triphenyltin.

Triphenyltin (TPT) is a widely used biocide known for its high toxicity to various organisms, including humans, and its potential contribution to environmental pollution. The aging process leads to progressive deterioration of physiological functions in the elderly, making them more susceptible to the toxic effects of environmental pollutants. This study aimed to investigate the mitigating effect of fecal transplantation in young mice on the toxicological impairment caused by TPT exposure. For the study, 18-month-old mice were divided into four groups with six replicates each. The control group was fed a basal diet, the TPT group was exposed to 3.75 mg/Kg TPT, the feces group received fecal transplantation from 8-week-old young mice, and the combined group was exposed to 3.75 mg/Kg TPT after receiving fecal transplantation. Compared with the elderly control group, TPT induced significant upregulation of mRNA expression of pro-inflammatory factors (IL-1ß, IL-6, TNF-α), while the anti-inflammatory factor gene IL-10 was significantly suppressed. The mRNA expression of intestinal barrier proteins (Claudin, Occludin, Muc2) was also significantly downregulated. However, fecal transplantation in young mice alleviated TPT-induced changes in inflammatory factors, ameliorated oxidative stress, and increased the activities of antioxidant enzymes (including SOD, CAT, GSH-Px). Further analysis using 16 s RNA showed that exposure to TPT led to changes in the composition of the intestinal flora. Untargeted metabolomics observations of feces from older mice revealed that exposure to TPT resulted in altered fecal metabolites. Fecal transplantation in young mice altered the microbiota of TPT-exposed older mice, especially by enhancing the levels of core probiotics. Similar beneficial effects were observed through untargeted metabolomics. Overall, this study highlights the potential benefits of young fecal transplantation in protecting the elderly from the toxicity of TPT, offering a promising approach to improve healthy aging.

Exploring the mechanism of enterotoxicity mediated by the microbiome-butyrate-PPAR axis in podophyllotoxin through the toxicological evidence chain (TEC) concept.

Podophyllotoxin (PPT) is a lignan derived from the roots and stems of the Podophyllum plant. However, its enterotoxicity restricts its clinical application. The underlying mechanisms by which PPT exerts its action remain largely elusive. This study aimed to evaluate the molecular mechanisms underlying PPT-induced enterotoxicity utilizing the concept of toxicological evidence chain. Changes in body weight, behavior, and histopathological and biochemical markers in rats were observed. Additionally, microbiome, metabolome, and transcriptome analyses were integrated to identify potential microorganisms, metabolic markers, and major pathways using a co-occurrence network. Our findings suggested that PPT induced pathological changes in rats, including weight loss, diarrhea, and inflammation accompanied by increased levels of IFN-γ, IL-5, IL-6, GRO/KC, and IL-12p70. The decrease in butyrate levels in the PPT group may be related to the enrichment of Firmicutes. The reduction of butyrate levels may impair the expression of PPARγ, subsequently promoting Escherichia-Shigella proliferation. Additionally, the suppression of PPARs pathway may result in the increased production of inflammatory factors, contributing to enterotoxicity. This study offers a novel understanding of the molecular mechanisms underlying PPT-induced enterotoxicity, making a significant contribution to developing strategies to mitigate PPT toxicity and prevent associated diseases.

Resveratrol alleviates fumonisin-induced intestinal cytotoxicity by modulating apoptosis, tight junction, and inflammation in IPEC-J2 porcine intestinal epithelial cells.

Fumonisins are common contaminants in the global food and environment, pose a variety of health risks to humans and animals. However, the method of mitigating fumonisin toxicity is still unclear. Resveratrol is a natural compound with antioxidant and anti-inflammatory properties. In this study, the protective effect of resveratrol against fumonisin-induced intestinal toxicity was investigated by the porcine intestinal epithelial cell line (IPEC-J2). The cells were treated with 0-40 µM fumonisin for 24 or 48 h with or without the 24 h resveratrol (15 µM) pretreatment. The data showed that resveratrol could alleviate the fumonisin B1 (FB1)-induced decrease in cell viability and amplify in membrane permeability. At the same time, it could reduce the accumulation of intracellular reactive oxygen species and increase the expression ranges of Nrf2 and downstream genes (SOD1 and NQO-1), thereby counteracting FB1-induced apoptosis. Furthermore, resveratrol was able to reduce the expression levels of inflammatory factors (TNF-α, IL-1ß, and IL-6), increase the expression levels of tight junction proteins (Claudin-1, Occludin, and ZO-1), and the integrity of the IPEC-J2 monolayer. Our data also showed that resveratrol could attenuate the toxicity of the co-occurrence of three fumonisins. It is implied that resveratrol represents a promising protective approach for fumonisin, even other mycotoxins in the future. This provided a new strategy for further blocking and controlling the toxicity of fumonisin, subsequently avoiding adverse effects on the human and animal health.

Ginseng Stem-and-Leaf Saponins Mitigate Chlorpyrifos-Evoked Intestinal Toxicity In Vivo and In Vitro: Oxidative Stress, Inflammatory Response and Apoptosis.

In recent years, the phenomenon of acute poisoning and organ damage caused by organophosphorus pesticides (OPs) has been a frequent occurrence. Chlorpyrifos (CPF) is one of the most widely used organophosphorus pesticides. The main active components of ginseng stems and leaves are total ginseng stem-and-leaf saponins (GSLSs), which have various biological effects, including anti-inflammatory, antioxidant and anti-tumor activities. We speculate that these could have great potential in the treatment of severe diseases and the relief of organophosphorus-pesticide-induced side effects; however, their mechanism of action is still unknown. At present, our work aims to evaluate the effects of GSLSs on the antioxidation of CPF in vivo and in vitro and their potential pharmacological mechanisms. Mice treated with CPF (5 mg/kg) showed severe intestinal mucosal injury, an elevated diamine oxidase (DAO) index, the decreased expression of occlusive protein-1 (ZO-1) and occlusive protein, an impaired intestinal mucosal oxidation system and intestinal villi relaxation. In addition, chlorpyrifos exposure significantly increased the contents of the inflammatory factor TNF-α and the oxidative-stress-related indicators superoxide dismutase (SOD), catalase (CAT), glutathione SH (GSH), glutathione peroxidase (GSH-PX), reactive oxygen species (ROS) and total antioxidant capacity (T-AOC); elevated the level of lipid peroxide malondialdehyde (MDA); reversed the expression of Bax and caspase; and activated NF-κB-related proteins. Interestingly, GSLS supplementation at doses of 100 and 200 mg/kg significantly reversed these changes after treatment. Similar results were observed in cultured RAW264.7 cells. Using flow cytometry, Hoechst staining showed that GSLSs (30 µg/mL, 60 µg/mL) could improve the cell injury and apoptosis caused by CPF and reduce the accumulation of ROS in cells. In conclusion, GSLSs play a protective role against CPF-induced enterotoxicity by inhibiting NF-κB-mediated apoptosis and alleviating oxidative stress and inflammation.

Potential Enterotoxicity of Phylogenetically Diverse Bacillus cereus Sensu Lato Soil Isolates from Different Geographical Locations.

Bacillus cereus sensu lato comprises Gram-positive spore-forming bacteria producing toxins associated with foodborne diseases. Three pore-forming enterotoxins, nonhemolytic enterotoxin (Nhe), hemolysin BL (Hbl), and cytotoxin K (CytK), are considered the primary factors in B. cereus sensu lato diarrhea. The aim of this study was to determine the potential risk of enterotoxicity among soil B. cereus sensu lato isolates representing diverse phylogroups and originated from different geographic locations with various climates (Burkina Faso, Kenya, Argentina, Kazakhstan, and Poland). While nheA- and hblA-positive isolates were present among all B. cereus sensu lato populations and distributed across all phylogenetic groups, cytK-2-positive strains predominated in geographic regions with an arid hot climate (Africa) and clustered together on a phylogenetic tree mainly within mesophilic groups III and IV. The highest in vitro cytotoxicity to Caco-2 and HeLa cells was demonstrated by the strains clustered within phylogroups II and IV. Overall, our results suggest that B. cereus sensu lato pathogenicity is a comprehensive process conditioned by many intracellular factors and diverse environmental conditions.IMPORTANCE This research offers a new route for a wider understanding of the dependency between pathogenicity and phylogeny of a natural bacterial population, specifically within Bacillus cereus sensu lato, that is widely distributed around the world and easily transferred into food products. Our study indicates differences in the phylogenetic and geographical distributions of potential enterotoxigenic B. cereus sensu lato strains. Hence, these bacilli possess a risk for human health, and rapid testing methods for their identification are greatly needed. In particular, the detection of the CytK enterotoxin should be a supporting strategy for the identification of pathogenic B. cereus sensu lato.

Inulin alleviates GenX-induced intestinal injury in mice by modulating the MAPK pathway, cell cycle, and cell adhesion proteins.

GenX, a substitute for perfluorooctanoic acid, has demonstrated potential enterotoxicity. The enterotoxic effects of GenX and effective interventions need further investigation. In the present study, the mice were administered GenX (2 mg/kg/day) with or without inulin supplementation (5 g/kg/day) for 12 weeks. Histopathological assessments revealed that GenX induced colonic gland atrophy, inflammatory cell infiltration, a reduction in goblet cell numbers, and decreased mucus secretion. Furthermore, a significant decrease in the protein levels of ZO-1, occludin, and claudin-5 indicated compromised barrier integrity. Transcriptomic analysis identified 2645 DEGs, which were mapped to 39 significant pathways. The TGF-ß, BMP6, and ß-catenin proteins were upregulated in the intestinal mucosa following GenX exposure, indicating activation of the TGF-ß pathway. Conversely, the protein expression of PAK3, CyclinD2, contactin1, and Jam2 decreased, indicating disruptions in cell cycle progression and cell adhesion. Inulin cotreatment ameliorated these GenX-induced alterations, partially through modulating the MAPK pathway, as evidenced by the upregulation of the cell cycle and cell adhesion proteins. Collectively, these findings suggested that GenX exposure triggered intestinal injury in mice by activating the TGF-ß pathway and disrupting proteins crucial for the cell cycle and cell adhesion, whereas inulin supplementation mitigated this injury by modulating the MAPK pathway.

Overview of T-2 Toxin Enterotoxicity: From Toxic Mechanisms and Detoxification to Future Perspectives.

Fusarium species produce a secondary metabolite known as T-2 toxin, which is the primary and most harmful toxin found in type A trichothecenes. T-2 toxin is widely found in food and grain-based animal feed and endangers the health of both humans and animals. T-2 toxin exposure in humans and animals occurs primarily through food administration; therefore, the first organ that T-2 toxin targets is the gut. In this overview, the research progress, toxicity mechanism, and detoxification of the toxin T-2 were reviewed, and future research directions were proposed. T-2 toxin damages the intestinal mucosa and destroys intestinal structure and intestinal barrier function; furthermore, T-2 toxin disrupts the intestinal microbiota, causes intestinal flora disorders, affects normal intestinal metabolic function, and kills intestinal epidermal cells by inducing oxidative stress, inflammatory responses, and apoptosis. The primary harmful mechanism of T-2 toxin in the intestine is oxidative stress. Currently, selenium and plant extracts are mainly used to exert antioxidant effects to alleviate the enterotoxicity of T-2 toxin. In future studies, the use of genomic techniques to find upstream signaling molecules associated with T-2 enterotoxin toxicity will provide new ideas for the prevention of this toxicity. The purpose of this paper is to review the progress of research on the intestinal toxicity of T-2 toxin and propose new research directions for the prevention and treatment of T-2 toxin toxicity.

Integrated Metabolomics and Lipidomics Analysis Reveals Lipid Metabolic Disorder in NCM460 Cells Caused by Aflatoxin B1 and Aflatoxin M1 Alone and in Combination.

Aflatoxin B1 (AFB1) and aflatoxin M1 (AFM1) are universally found as environmental pollutants. AFB1 and AFM1 are group 1 human carcinogens. Previous sufficient toxicological data show that they pose a health risk. The intestine is vital for resistance to foreign pollutants. The enterotoxic mechanisms of AFB1 and AFM1 have not been clarified at the metabolism levels. In the present study, cytotoxicity evaluations of AFB1 and AFM1 were conducted in NCM 460 cells by obtaining their half-maximal inhibitory concentration (IC50). The toxic effects of 2.5 µM AFB1 and AFM1 were determined by comprehensive metabolomics and lipidomics analyses on NCM460 cells. A combination of AFB1 and AFM1 induced more extensive metabolic disturbances in NCM460 cells than either aflatoxin alone. AFB1 exerted a greater effect in the combination group. Metabolomics pathway analysis showed that glycerophospholipid metabolism, fatty acid degradation, and propanoate metabolism were dominant pathways that were interfered with by AFB1, AFM1, and AFB1+AFM1. Those results suggest that attention should be paid to lipid metabolism after AFB1 and AFM1 exposure. Further, lipidomics was used to explore the fluctuation of AFB1 and AFM1 in lipid metabolism. The 34 specific lipids that were differentially induced by AFB1 were mainly attributed to 14 species, of which cardiolipin (CL) and triacylglycerol (TAG) accounted for 41%. AFM1 mainly affected CL and phosphatidylglycerol, approximately 70% based on 11 specific lipids, while 30 specific lipids were found in AFB1+AFM1, mainly reflected in TAG up to 77%. This research found for the first time that the lipid metabolism disorder caused by AFB1 and AFM1 was one of the main causes contributing to enterotoxicity, which could provide new insights into the toxic mechanisms of AFB1 and AFM1 in animals and humans.

Triclocarban exposure aggravates dextran sulfate sodium-induced colitis by deteriorating the gut barrier function and microbial community in mice.

Triclocarban (TCC) is an antibacterial component widely used in personal care products with potential toxicity possessing public health issues. Unfortunately, enterotoxicity mechanisms of TCC exposure remain largely unknown. Using a combination of 16S rRNA gene sequencing, metabolomics, histopathological and biological examinations, this study systematically explored the deteriorating effects of TCC exposure on a dextran sulfate sodium (DSS)-induced colitis mouse model. We found that TCC exposure at different doses significantly aggravated colitis phenotypes including shortened colon length and altered colonic histopathology. Mechanically, TCC exposure further disrupted intestinal barrier function, manifested by significant downregulation of the number of goblet cells, mucus layer thickness and expression of junction proteins (MUC-2, ZO-1, E-cadherin and Occludin). The gut microbiota composition and its metabolites such as short-chain fatty acids (SCFAs) and tryptophan metabolites were also markedly altered in DSS-induced colitis mice. Consequently, TCC exposure markedly exacerbated colonic inflammatory status of DSS-treated mice by activating NF-κB pathway. These findings provided new evidence that TCC could be an environmental hazards for development of IBD or even colon cancer.

Destruction of self-derived PAMP via T3SS2 effector VopY to subvert PAMP-triggered immunity mediates Vibrio parahaemolyticus pathogenicity.

Cyclic di-guanosine monophosphate (c-di-GMP) is a unique bacterial second messenger but is hijacked by host cells during bacterial infection as a pathogen-associated molecular pattern (PAMP) to trigger STING-dependent immune responses. Here, we show that upon infection, VopY, an effector of Vibrio parahaemolyticus, is injected into host cells by type III secretion system 2 (T3SS2), a secretion system unique to its pathogenic strains and indispensable for enterotoxicity. VopY is an EAL-domain-containing phosphodiesterase and is capable of hydrolyzing c-di-GMP. VopY expression in host cells prevents the activation of STING and STING-dependent downstream signaling triggered by c-di-GMP and, consequently, suppresses type I interferon immune responses. The presence of VopY in V. parahaemolyticus enables it to cause both T3SS2-dependent enterotoxicity and cytotoxicity. These findings uncover the destruction of self-derived PAMPs by injecting specific effectors to suppress PAMP-triggered immune responses as a unique strategy for bacterial pathogens to subvert immunity and cause disease.

Characterization of triclosan-induced hepatotoxicity and triclocarban-triggered enterotoxicity in mice by multiple omics screening.

Triclosan (2,4,4'-trichloro-2'-hydroxydiphenyl ether, TCS) and triclocarban (3,4,4'-trichloro-carbanilide, TCC) are two antimicrobial agents commonly used for personal care products. Previous studies primarily focused on respective harmful effects of TCS and TCC. In terms of their structural similarities and differences, however, the structure-toxicity relationships on health effects of TCS and TCC exposure remain unclear. Herein, global 1H NMR-based metabolomics was employed to screen the changes of metabolic profiling in various biological matrices including liver, serum, urine, feces and intestine of mice exposed to TCS and TCC at chronic and acute dosages. Metagenomics was also applied to analyze the gut microbiota modulation by TCS and TCC exposure. Targeted MS-based metabolites quantification, histopathological examination and biological assays were subsequently conducted to supply confirmatory information on respective toxicity of TCS and TCC. We found that oral administration of TCS mainly induced significant liver injuries accompanied with inflammation and dysfunction, hepatic steatosis fatty acids and bile acids metabolism disorders; while TCC exposure caused marked intestine injuries leading to striking disruption of colonic morphology, inflammatory status and intestinal barrier integrity, intestinal bile acids metabolism and microbial community. These comparative results provide novel insights into structure-dependent mechanisms of TCS-induced hepatotoxicity and TCC-triggered enterotoxicity in mice.

Crucial Function of Caveolin-1 in Deoxynivalenol-Induced Enterotoxicity by Activating ROS-Dependent NLRP3 Inflammasome-Mediated Pyroptosis.

Deoxynivalenol (DON) is one of the most pervasive contaminating mycotoxins in grain, and exposure to DON is known to cause acute and chronic intestinal damage. As the gut is the most important target organ of DON, it is essential to identify the pivotal molecules involved in DON-induced enterotoxicity as well as the potential regulatory mechanisms. In the present study, we found that DON treatment dramatically decreased the jejunal villus height and increased the crypt depth in mice. DON exposure induced oxidative stress and NLRP3 inflammasome activation while increasing the levels of pyroptosis-related factors GSDMD, ASC, Caspase-1 P20, and IL-1ß and inflammatory cytokines IL-18, TNF-α, and IL-6. In vitro, 0.5-2 µM DON caused cytotoxicity and oxidative stress, as well as NLRP3-mediated pyroptosis in IPEC-J2 cells. Furthermore, DON treatment substantially improved the expression of Caveolin-1 (Cav-1) in vitro and in vivo. Interestingly, Cav-1 knockdown effectively attenuated DON-induced oxidative stress and NLRP3-mediated pyroptosis in IPEC-J2 cells. Meanwhile, treatment with the antioxidant NAC significantly alleviated DON-induced cytotoxicity and pyroptosis in IPEC-J2 cells. Likewise, after inhibiting NLRP3 inflammasome activation with the inhibitor MCC950, DON-induced cytotoxicity, pyroptosis, and inflammatory response were attenuated. However, NLRP3 inhibition did not affect Cav-1 expression. In conclusion, our study demonstrated that pyroptosis may be an underlying mechanism in DON-induced intestinal injury, and Cav-1 plays a pivotal role in DON-induced pyroptosis via regulating oxidative stress, which suggests a novel strategy to overcome DON-induced enterotoxicity.

The Enterotoxin Production and Antimicrobial Resistance of Campylobacter Strains Originating from Slaughter Animals.

The pathogenicity of animal-origin Campylobacter strains, including antimicrobial resistance and enterotoxigenicity, was determined in this study. Overall, 149 Campylobacter isolates originating from cattle, swine and poultry were tested. The antimicrobial resistance profiles were examined by the diffusion disk method. The dominant resistance pattern was CIP_TET. The resistance rates for ciprofloxacin among swine, cattle and poultry isolates were 84%, 51% and 66%, respectively; for tetracycline, they were 82%, 57.1% and 76%, respectively. None of the obtained isolates was resistant to all four antimicrobials tested. The ability to produce enterotoxins was assessed by the use of a suckling mouse bioassay, with intestinal fluid accumulation as a positive result, and by CHO assay, with the elongation of cells as a positive result. The ability to produce enterotoxins was significantly higher among cattle isolates (61.2% and 71.4% positive isolates, respectively, in the bioassay and the CHO assay) than among swine (16% and 32% positive isolates, respectively) or poultry isolates (14% and 22% positive isolates, respectively). A strong positive correlation between in vitro and in vivo enterotoxicity tests was demonstrated.

Regulatory effects of flavonoids luteolin on BDE-209-induced intestinal epithelial barrier damage in Caco-2 cell monolayer model.

Polybrominated diphenyl ethers (PBDEs) are persistent organic pollutants (POPs). They are constantly detected in foods. PBDEs can disrupt the intestinal flora, but enterotoxicity is unknown. Luteolin, one kind of flavonoid, has drawn increasing interest as an agent that strengthens the intestinal barrier. This study aimed to evaluate the mitigating effect of luteolin on damage to the intestinal barrier induced by decabromodiphenyl ether (BDE-209) in a Caco-2 cell monolayer model. Results showed that luteolin mitigated BDE-209-induced damage to intestinal epithelial barrier by reducing the levels of reactive oxygen species (ROS), increasing the activity of superoxide dismutase (SOD) and glutathione (GSH), suppressed the secretion of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1ß), and increased the expression of tight junction (TJ) proteins (ZO-1, occludin, and claudin-1). Furthermore, the protective effects were related to the inhibition of extracellular regulated protein kinases (ERK) and nuclear factor kappa-B (NF-κB)/myosin light chain kinase (MLCK) signaling pathways, and the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathways. This study is the first to provide strong evidence that BDE-209 can damage the intestinal barrier, and we here investigated the important protective effect of luteolin, which may lay the foundation for the development of luteolin as a dietary supplement to strengthen the intestinal barrier.

The Possible Transmission and Potential Enterotoxicity of Bacillus cereus on Lettuce Farms in Five Chinese Provinces.

Bacillus cereus is a well-characterized human pathogen that produces toxins associated with diarrheal and emetic foodborne diseases. To investigate the possible transmission of B. cereus on lettuce farms in China and determine its enterotoxicity, (I) a total of 524 samples (lettuce: 332, soil: 69, water: 57, manure: 57, pesticide: 9) were collected from 46 lettuce farms in five Chinese provinces, (II) multilocus sequence typing (MLST) was used to classify B. cereus isolates and for trace analysis, and (III) the presence of toxin genes and enterotoxins (Hbl and Nhe) was detected in 68 strains. The results showed that one hundred and sixty-one lettuce samples (48.5%) tested positive for B. cereus at levels ranging from 10 to 5.3 × 104 CFU/g. Among the environmental sample categories surveyed, the highest positive rate was that of the pesticide samples at 55.6%, followed by soil samples at 52.2% and manure samples at 12.3%. Moreover, one hundred isolates of B. cereus yielded 68 different sequence types (STs) and were classified into five phylogenetic clades. Furthermore, Nhe toxin genes (nheA, nheB, nheC) were broadly distributed and identified in all 68 strains (100%), while Hbl toxin genes (hblA, hblC, hblD) were present in 61 strains (89.7%), entFM was detected in 62 strains (91.2%), and cytK was found in 29 strains (42.6%). All strains were negative for ces. As for the enterotoxin, Nhe was observed in all 68 isolates carrying nheB, while Hbl was present in 76.5% (52/68) of the strains harboring hblC. This study is the first report of possible B. cereus transmission and of its potential enterotoxicity on lettuce farms in China. The results showed that soil and pesticides are the main sources of B. cereus on lettuce farms in China, and the possible transmission routes are as follows: soil-lettuce, manure-lettuce, pesticide-lettuce, manure-soil-lettuce, and water-manure-soil-lettuce. Furthermore, the B. cereus isolates, whether from lettuce or the environment, pose a potential risk to health.

Next-Generation Intestinal Toxicity Model of Human Embryonic Stem Cell-Derived Enterocyte-Like Cells.

The gastrointestinal tract is the most common exposure route of xenobiotics, and intestinal toxicity can result in systemic toxicity in most cases. It is important to develop intestinal toxicity assays mimicking the human system; thus, stem cells are rapidly being developed as new paradigms of toxicity assessment. In this study, we established human embryonic stem cell (hESC)-derived enterocyte-like cells (ELCs) and compared them to existing in vivo and in vitro models. We found that hESC-ELCs and the in vivo model showed transcriptomically similar expression patterns of a total of 10,020 genes than the commercialized cell lines. Besides, we treated the hESC-ELCs, in vivo rats, Caco-2 cells, and Hutu-80 cells with quarter log units of lethal dose 50 or lethal concentration 50 of eight drugs-chloramphenicol, cycloheximide, cytarabine, diclofenac, fluorouracil, indomethacin, methotrexate, and oxytetracycline-and then subsequently analyzed the biomolecular markers and morphological changes. While the four models showed similar tendencies in general toxicological reaction, hESC-ELCs showed a stronger correlation with the in vivo model than the immortalized cell lines. These results indicate that hESC-ELCs can serve as a next-generation intestinal toxicity model.

In Vivo Study of Entero- and Hepatotoxicity of Silver Nanoparticles Stabilized with Benzyldimethyl-[3-myristoylamine)-propyl]ammonium Chloride (Miramistin) to CBF1 Mice upon Enteral Administration.

Silver nanoparticles (AgNPs) are the most widely studied antimicrobial nanomaterials. However, their use in biomedicine is currently limited due to the availability of data that prove the nanosilver toxicity associated primarily with oxidative stress development in mammalian cells. The surface modification of AgNPs is a potent technique of improvement of their biocompatibility. The synthetic or natural compounds that combine zero or low toxicity towards human and animal organisms with inherent antimicrobial properties are the most promising stabilizing agents, their use would also minimize the risks of microorganisms developing resistance to silver-based materials. We used a simple technique to obtain 30-60 nm AgNPs stabilized with benzyldimethyl[3-myristoylamine)-propyl]ammonium chloride monohydrate (BAC)-a well-known active ingredient of many antibacterial drugs. The objective of the study was to assess the AgNPs-BAC entero- and hepatotoxicity to CBF1 mice upon enteral administration. The animals were exposed to 0.8-7.5 mg/kg doses of AgNPs-BAC in the acute and to 0.05-2.25 mg/kg doses of AgNPs-BAC in the subacute experiments. No significant entero- and hepatotoxic effects following a single exposure to doses smaller than 4 mg/kg were detected. Repeated exposure to the doses of AgNPs-BAC below 0.45 mg/kg and to the doses of BAC below 0.5 mg/kg upon enteral administration also led to no adverse effects. During the acute experiment, the higher AgNPs-BAC dose resulted in increased quantities of aminotransferases and urea, as well as the albumin-globulin ratio shift, which are indicative of inflammatory processes. Besides, the relative mass of the liver of mice was smaller compared to the control. During the subacute experiment, the groups treated with the 0.25-2.25 mg/kg dose of AgNPs-BAC had a lower weight gain rate compared to the control, while the groups treated with the 2.25 mg/kg dose of AgNPs-BAC showed statistically significant variations in the blood serum transaminases activity, which indicated hepatosis. It should be noted that the spleen and liver of the animals from the groups treated with the 0.45 and 2.25 mg/kg dose of AgNPs-BAC were more than two times smaller compared to the control. In the intestines of some animals from the group treated with the 2.25 mg/kg dose of AgNPs-BAC small areas of hyperemia and enlarged Peyer's patches were observed. Histological examination confirmed the initial stages of the liver and intestinal wall inflammation.

Effects of curcumin on performance, antioxidation, intestinal barrier and mitochondrial function in ducks fed corn contaminated with ochratoxin A.

Curcumin has been attributed with antioxidant, anti-inflammatory, antibacterial activities, and has shown highly protective effects against enteropathogenic bacteria and mycotoxins. Ochratoxin A (OTA) is one of the major intestinal pathogenic mycotoxins. The possible effect of curcumin on the alleviation of enterotoxicity induced by OTA is unknown. The effects of dietary curcumin supplementation on OTA-induced oxidative stress, intestinal barrier and mitochondrial dysfunctions were examined in young ducks. A total of 540 mixed-sex 1-day-old White Pekin ducklings with initial BW (43.4±0.1 g) were randomly assigned into controls (fed only the basal diet), a group fed an OTA-contaminated diet (2 mg/kg feed), and a group fed the same OTA-contaminated feed plus 400 mg/kg of curcumin. Each treatment consisted of six replicates, each containing 30 ducklings and treatment lasted for 21 days. There was a significant decrease in average daily gain (ADG) and increased feed : gain caused by OTA (P<0.05); curcumin co-treatment prevented the decrease in BW and ADG compared with the OTA group (P<0.05). Histopathological and ultrastructural examination showed clear signs of enterotoxicity caused by OTA, but these changes were largely prevented by curcumin supplementation. Curcumin decreased the concentrations of interleukin-1ß, tumor necrosis factor-α and malondialdehyde, and increased the activity of glutathione peroxidase induced by OTA in the jejunal mucosa of ducks (P<0.05). Additionally, curcumin increased jejunal mucosa occludin and tight junction protein 1 mRNA and protein levels, and decreased those of ρ-associated protein kinase 1 (P<0.05). Notably, curcumin inhibited the increased expression of apoptosis-related genes, and downregulated mitochondrial transcription factors A, B1 and B2 caused by OTA without any effects on RNA polymerase mitochondrial (P<0.05). These results indicated that curcumin could protect ducks from OTA-induced impairment of intestinal barrier function and mitochondrial integrity.

Molecular identification of diarrheal Aeromonas using immuno magnetic polymerase chain reaction (IM-PCR) technique: a comparative study with conventional culture method.

BACKGROUND: Aeromonas are ubiquitous bacteria causing many clinical conditions including acute diarrhea. Diarrheagenic Aeromonas harbors aerolysin gene secreting virulent enterotoxin, aerolysin. OBJECTIVES: To develop a molecular and immunological based method for detection of Aeromonas. METHODS: Diarrheal Aeromonas strains were identified from stool samples using culture, enterotoxicity testing using mice model. During immune magnetic polymerase chain reaction IM-PCR protocol, aerolysin specific antibodies were bound with immuno magnetic binding. Sensitivity and specificity tests for IM-PCR were conducted. RESULTS: There was high detection of Aeromonas using IM-PCR (12.4 %) technique when compared to low isolation with culture (5.1%). Our study confirmed that some strains of enterotoxic Aeromonas strains were uncultivable. Enterotoxicity tests on culture isolates revealed many strains were negative. IM-PCR detected high, (62/500) rate of identification of Aeromonas with aerolysin toxin gene. Aeromonas species identified after IM-PCR were A. hydrophila (40.3% ), A. veronii (17.7 %), A. caviae (14.5 %), A. trota (11.2 %), A. jandei (9.6 %) and A. schuberti (6.4%). All A. trota strains were undetected by cultivation. CONCLUSION: High sensitivity and specificity of IM-PCR are due to preparation of aerolysin antibodies and immuno magnetic binding, prior to PCR. Since diseases due to Aeromonas are increasingly reported, IM-PCR is recommended for detection from clinical specimens.

Review of Newly Identified Functions Associated With the Heat-Labile Toxin of Enterotoxigenic Escherichia coli.

Heat-labile toxin (LT) is a well-characterized powerful enterotoxin produced by enterotoxigenic Escherichia coli (ETEC). This toxin is known to contribute to diarrhea in young children in developing countries, international travelers, as well as many different species of young animals. Interestingly, it has also been revealed that LT is involved in other activities in addition to its role in enterotoxicity. Recent studies have indicated that LT toxin enhances enteric pathogen adherence and subsequent intestinal colonization. LT has also been shown to act as a powerful adjuvant capable of upregulating vaccine antigenicity; it also serves as a protein or antigenic peptide display platform for new vaccine development, and can be used as a naturally derived cell targeting and protein delivery tool. This review summarizes the epidemiology, secretion, delivery, and mechanisms of action of LT, while also highlighting new functions revealed by recent studies.