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Aims: Food safety has emerged as an important global issue with international trade and public health implications. Staphylococcus aureus is recognized as an important cause of food poisoning related to the consumption of raw, undercooked or mishandled foods worldwide. The aim of this study was to investigate the presence and the frequency of enterotoxin producing S. aureus and SE genes in meat samples collected from meat retail outlets and restaurants in Zanjan, Iran.
Materials and Methods: In this cross sectional study, from March to June 2015, a total of 90 individual meat samples were collected from meat retail outlets and restaurants in Zanjan, Iran and investigated the frequency of enterotoxin producing S. aureus and SE genes. The meat samples were immediately homogenized and cultured on Baird parker agar and subjected for confirmatory biochemical tests and molecular detection of femA, sea, seb, sec, sed and see genes.
Findings: A total of 31 (34.4%) meat samples were positive for the presence of S. aureus. The frequency of S. aureus in raw meat (23.3%) was higher than cooked meat samples (11.1%). Enterotoxin-producing capacity was determined in 18 (20.0%) out of 90 homogenized meat samples using ELISA technique. The most prevalent SE gene was sea (38.7%), followed by see (22.6%), sec (16.1%) and seb (12.9%). SE genes were not found in strains isolated from cooked meat samples.
Conclusion: Detection of enterotoxigenic S. aureus in raw meat samples shows a probable risk for public health.
 

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Wild grasses are the most important primary feedstuffs which are susceptible to contamination with toxigenic fungi belonging to Aspergillus spp. In order to explore diversity of Aspergillus species associated with the inflorescences of gramineous weeds, infected inflorescences were collected from wild grasses in western parts of Iran. Fifty-six Aspergillus isolates were obtained from all diseased spikes and based on morphological features identified as 4 species i.e. Aspergillus niger (26) followed by Aspergillus flavus (24), Aspergillus fumigatus (4), andAspergillusjaponicus (2). The identification of A. flavus was confirmed using species specific primers of AFLA-F/AFLA-R by producing amplicons about 413 bp. In this study, aflatoxins (AFs) contamination of wild grasses was evaluated by enzyme linked immunosorbent assay (ELISA). Natural occurrence of AFs could be detected in 24 samples ranging from 0.63-134.86 μg/kg. The highest AFT levels were detected in samples from Ravansar, Bisetoon, Mahidasht, and Sarpol Zehab (up to 50 μg/kg), which is more than the recommended limits by European :union: standard and National Standard of Iran (20 µg/kg for animal feed).

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Aim: Cereals and cereal-based products are prone to be infected by mycotoxin-producing fungi. The aim of this study was to investigate the level of contamination caused by 11 major mycotoxins in wheat samples collected from wheat silos in Tehran and Alborz provinces using UHPLC-MS/MS device.
Materials & Methods: Samples preparation was performed based on the extraction and purification procedures using acetonitrile/water/acetic acid solvents and Myco6in1 immunoaffinity columns, respectively. Selected mycotoxins were detected simultaneously using reversed phase ultra-high performance liquid chromatography coupled with tandem mass spectrometry (UHPLC-MS/MS) with electrospray ionization technique in positive-ion mode in a 15-minute run in the MRM program. Spiked samples calibration curve was used to overcome the matrix effects and to determine the residual mycotoxins.
Findings: Quantification and detection limits for AFB1 and OTA mycotoxins were 2 and 0.7 ppb; for DON, FB1, and FB2 were 100 and 33.3 ppb; for ZER were 50 and 16.6 ppb: for AFB2, AFG1, AFG2, and T-2 were 5 and 1.6 ppb; and for HT-2 were 20 and 6.6 ppb, respectively. Good precision and linearity was observed for mycotoxins. The average recovery rate of mycotoxins was in the range of 72-123 %, and the relative standard deviation (RSDr), indicating the method accuracy, was between 0.6-24.2 %. The validated method for analyzing the 30 wheat samples was used to evaluate the residual mycotoxins. OTA, T-2, and HT-2 mycotoxins were found in wheat samples. Only in one sample, the level of residual OTA exceeded the allowable limit set by the Iranian National Standards Organization.
Conclusion: The present study results highlighted the need for monitoring wheat and wheat-based products and the implementation of control and preventive measures in wheat fields, storage warehouses, and flour factories.

 

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Bioassay results confirmed the role of low molecular weight phytotoxin in the patho-genesis of Verticillium albo-atrum. The metabolites separated from 21-day-old culture fil-trate by adsorption on the resin Amberlite XAD-4, and further chromatographed on Bio-Gel P2 polyacrylamide gel, induced chlorosis and necrosis on the leaflets of tomato and potato cultivars, similar to those caused by the fungus on diseased plants. Leaflets from tolerant cultivars were much less sensitive to the toxin (s) than those from the susceptible ones. In the presence of toxin(s) plant tissues and individual cells showed ion-leakage and cell death to an extent relating to the plants reaction to the fungus. The relative specificity observed during pathogenicity tests between potato and tomato and their related isolates was shown to be related to the action of toxin (s).

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 Aspergillus flavus is one of the important species of molds that can produce toxins during improper storage of wheat grains. In this study, different amounts of calcium oxide (0, 0.5, and 1%) were mixed with wheat samples containing mold spores. After 20 days, the samples were exposed to gamma radiation (0, 5, 10, 15, and 20 KGy). The presence of A. flavus, Aflatoxin B₁ (AFB₁), aflatoxin B₂ (AFB₂), aflatoxin G₁ (AFG₁), and aflatoxin G₂ (AFG₂) was assessed in samples. The results indicated that the effects of calcium oxide, gamma irradiation, and their interactions were significant on A. flavus, AFB₁, and AFB₂ contamination. Furthermore, other toxins like AFG₁ and AFG₂ were not found in the samples. An additional reduction in AFB₁ and AFB₂ was observed when irradiation was accompanied by Cao, and the maximum inhibition of aflatoxin production was achieved at 0.5% CaO. Consequently, based on the standard maximum limit of 10 KGy for cereals, the findings of this research suggest that 0.5% of calcium oxide and 10 KGy of irradiation could be applied in the storage of wheat grains to mitigate A. flavus, AFB₁, and AFB₂.

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Mycotoxins are the toxic metabolites produced by some species of mould genera such as Aspergillus, Penicillium and Fusarium. Mycotoxins are carcinogenic, mutagenic, teratogenic and immunosuppressive for the most animal species and humans. Humans are exposed by aflatoxins and ochratoxin A via foods such as milk, cereals and various spices. The objective of this study was to determine the aflatoxin and ochratoxin A (OTA) contents of Iranian (Sabzevar) red pepper using high performance liquid chromatography (HPLC) with fluorescence detector and Immunoaffinity column clean-up. An isocratic mobile phase of water–acetonitrile–methanol (60:25:15, v/v/v), and acetonitrile–water–acetic acid (51:47:2, v/v/v) with a flow rate of 1.0 ml/min was used for aflatoxins and ochratoxin A determination, respectively. Limit of detection (LOD) and limit of quantification (LOQ) were respectively, 0.1 and 0.3 μg/kg for AFB1 and AFB2, 0.14 and 0.45 μg/kg for AFG1 and AFG2, 0.15 and 0.5 μg/kg for OTA. The values of average recoveries of mycotoxins were 71.1–96.2%. When AFB1 and AFG1 were added to red pepper at the level of 10 μg/kg, AFB2 and AFG2 at the level of 2 μg /kg and OTA at the level of 5 μg/kg, the recovery ranges of 82.7–89.2% for AFB1, 79.3–114.2% for AFB2, 66.5–71.9% for AFG1, 66.3–92.5% for AFG2 and 61.1–80% for OTA were obtained. 36 samples of pepper were collected from the farm and were dried by sun up to standard moisture (Max 11%). Total aflatoxins (AFs) were detected in 25 out of 36 samples (69.4% of incidence) and the contamination levels were 0.4-15.6 μg/kg. The highest incidence of contamination was aflatoxin B1 and was found in 25 out of 36 samples. Seven (19.5%) and three (8.34%) out of 36 samples had levels above the regulatory limits according to the European :union: for AFB1 (5 μg/kg) and total aflatoxins (10 μg/kg), respectively.  OTA was detected in six samples (16.7%) at the ranging from 0.74-2.17 μg/kg. None of the samples had OTA levels higher than the legal acceptable limits.  

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Backgrounds: Bacterial toxins are virulence factors that manipulate the functions of host cells and take over the control of main processes of living organisms. Importantly, they are non-curable, non-contagious, and non-infectious by chemotherapeutic agents and/or antibiotics. The multifactorial nature of the toxicity of bacterial toxins has made their investigation more complicated.
Methods: In this review, we investigated some biological activities, structure, and action mechanism of several bacterial toxins using data from studies published in major international databases.
Conclusion: Bacterial protein toxins are very diverse based on size, structure and mode of action. Based on the structure and the type of cell surface receptors, the mentioned toxins have activity on the cell surface (signal transmission, pore formation) or have intracellular activity. Many bacterial protein toxins have the ability to enter the cell by the endocytosis mechanism, and according to their intracellular targets, they can induce different intracellular effects, which in many cases lead to the death of the target cell. A large and interesting group of bacterial toxins are enterotoxins. The majority of toxigenic bacteria are environmental, and the digestive system is one of the most common ways of entering or encountering environmental bacteria or their toxic products through eating food. Many enteropathogenic bacteria produce enterotoxins in food, in the intestinal lumen or on the surface of the intestinal mucosa. Also, some entero-invasive bacteria penetrate the cells by inoculating some toxins into the intestinal cells. The challenge of studying bacterial toxins and enterotoxins lies in their complex nature and the need for comprehensive characterization, but the future holds promise with advancements in technology and interdisciplinary approaches to further our understanding and develop effective strategies for prevention and treatment.

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Immunotoxins are an attractive way to treat cancer; in this method, high-cytotoxic protein toxins target cancer cells specifically. An immunotoxin consists of a targeting component (an antibody, cytokine, or other protein that binds to the cell), that is chemically conjugated or fused in DNA level to a cytotoxic cargo (a bacterium, plant or cytotoxic human protein). Immunotoxin, with the help of specific receptors, recognizes the target cell and enters the cell by endocytosis. After entering the cytocell, it kills the target cancer cell with the help of a toxic component. Although various immunotoxins with different structures have been studied and tested in recent decades, only three immunotoxins Denileukin Diftitox, Tagraxofusp and Moxestumomab Pasudotox - have been clinically approved for the treatment of leukemia. In this article, we review important research and two challenges in production and development of immunotoxins that have limited their clinical success. Further, we highlight methods to overcome these obstacles. These challenges include target and non-target cell toxicity and immunization.

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The objective of this study was to assess the microbial contamination of Razavi Khorasan (Iran) hot red pepper. The natural occurrence of aflatoxins and ochratoxin A in those samples was also investigated. For this purpose, 36 samples of this kind of pepper were collected from a farm and sun-dried. Standard and established methods were used for both microbiological analyses and mycotoxins identification. Total aerobic mesophilic counts of samples varied from 10² to 4×10⁶ cfu g^-1. Coliforms were present at high levels in all samples ranging from 1.9×10² to 3.52×10⁶ cfu g^-1that may indicate inappropriate hygienic quality of samples. 42% of the samples were of unsatisfactory quality due to the presence of E. coli. In all samples examined, sulphite-reducing clostridia (SRC) was below detection limit and Salmonella spp. was not detected. Fungi were found in all of the collected samples. Mold and yeast were generally high ranging from 2.4×10³ to 4.6×10⁶ cfu g^-1and the most predominant fungal genera were Aspergillus spp., Penicillium spp and Rhizopus spp. Considering the results obtained, the samples analyzed contain a high level of microorganisms and only two samples (6%) had acceptable levels for all microbial factors according to EU Commission Recommendation (directive2004/24/EC). 69% and 17% of samples were found contaminated with total aflatoxins and ochratoxin A, respectively, that might contribute to health hazards for humans. Overall, The Razavi Khorasan hot red pepper samples collected for this study were contaminated with microorganisms and mycotoxins, which suggests that hygiene practice pre- and post-harvesting must be improved if the region is to exploit fully the potential for this valuable product.

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 To evaluate the effect of roasting and Dutching processes on the stability of B-aflatoxins (AFB1+AFB2), experimental units of cocoa beans contaminated with aflatoxin at a concentration of 220.7 ng g^-1 were roasted at 250ºC for 15 minutes. Roasting conditions caused a notable reduction in the aflatoxin content (up to 71%). The resulting cocoa liquors contaminated with 63.9 ng g^-1 were thermal-alkaline treated with sodium, potassium, and calcium hydroxide at three different concentrations (10, 20, and 30 g kg^-1). The effects of the two variables (alkali type and concentration) were analyzed as a completely randomized factorial 3´3 design. At a concentration of 10 g kg^-1, the aflatoxin reduction was more effective when using NaOH and Ca(OH)₂ (up to 94%) than when using KOH (up to 88%); however, at concentrations of 20 and 30 g kg^-1, all of the three chemicals were almost equally effective for aflatoxin degradation (up to 98%). According to these results, higher reductions in aflatoxin levels were achieved during the roasting and an effective extra-reduction occurred during the Dutching process. Treatment of cocoa liquors with these alkalizing agents not only improved their physicochemical properties, but also enhanced their sanitary quality through the reduction in the aflatoxin content.

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Aflatoxins are acute toxigenic and stable in heating process. Therefore determination of its concentration in milk is critical. The aim of this study was to evaluate aflatoxin M1 concentration in packaged milk produced in Mashhad and Gonabad. Aflatoxin concentration in milk samples was detected by ELISA (Enzyme Linked Immunosorbent Assay) technique and compared by limit of EU regulation and ISIRI. Totally 80 samples were analyzed for AFM1. The lower layer after separation fat by centrifuge was tested by ELIZA at 450 nm. The average concentration and standard deviation of aflatoxin M1 in the packaged milks produced in Mashhad were 0.040±0.015, 0.021±0.007, 0.022±0.003, 0.05±0.008 and in the packaged milks produced in Gonabad were 0.024±0.019, 0.027±0.021 & 0.031±0.029 ppb respectively. In overall, 13% of the milk samples had the aflatoxin M1 concentration higher than the 0.05 ppb (Iranian standard) and only one sample had aflatoxin M1 greater than 0.08 ppb. According to the results in this study, the average aflatoxin M1 levels of all factories was below European community and Codex Alimentary and ISIRI. The data showed that the differences of between two cities were not statistically significant.

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Assessing factor affecting Iranian Pistachio export due to comparative advantage and share of Iran in international market of this crop is very important. In recent years, pistachio exports has faced many challenges including limitation of aflatoxin maximum of importing countries. In the present study, factors affecting on Pistachio export with emphasis on the role of aflatoxins were evaluated by gravity model. For obtained this goal, the major importing countries pistachio were determined and panel data from the years 1990-2017 were used. The results of gravity model estimation showed that the limitation of aflatoxin, GDP, population and border for selected importing countries has significant positive effect on the export of Iran Pistachio. The result suggested that Iran to maintain it is share in the Pistachio global market, pistachio with high quality and lesser aflatoxin have to be product, as well as, sanitation laws are approved based on international laws could be very useful.