Background
Aflatoxins (AFTs) produced by Aspergillus flavus and A. parasiticus recognized as the most critical dietary risk factors. AFTs can be present in the environment, soil and food crops and can cause serious effects in both animals and humans, and aflatoxin B1 (AFB1) has been recognized by the World Health Organization as one of the most potent naturally occurring group 1A carcinogens. AFT consists of a difuran ring and a coumarin ring, structurally stable, heat-resistant, and can only be degraded above 280°C. Based on fluorescence, AFTs are broadly categorized into AFB1 and AFB2 (blue) types, and AFG1 and AFG2 (green) types. AFB1 is a derivative of aflatoxin and is considered the most toxic AFT.
Aflatoxins contaminate agricultural products during growth, harvest, transportation and storage, and current food processing methods and traditional storage conditions cannot completely eliminate AFT contamination from the food supply chain. People can be exposed to AFB1 through dietary intake, skin contact, and inhalation of contaminated dust. Most AFB1 is absorbed by passive transport in the duodenum and jejunum and then accumulates in the liver, kidney and spleen, of which the liver is the primary target organ for AFB1. AFB1 is metabolized in the liver by the enzyme P450 to the carcinogen AFB1-8,9-epoxide (AFBO), which consists of the endo-8,9-epoxide (endo-AFBO) and exo-8,9-epoxide (exoAFBO) isomers. CYP1A2 oxidizes AFB1 to endo- and exo-AFBO and AFM1, whereas CYP3A4 catalyzes the oxidation of AFB1 to exo-AFBO and AFQ1. The different AFB1 metabolites are mainly excreted in the feces and urine.
The susceptibility of livestock to AFB1 varies by species. Monogastric animals are more susceptible to AFB1 than ruminants because the gut microbes of the latter can metabolize mycotoxins. Chronic exposure of livestock to low concentrations of AFB1 is more common than acute poisoning. Prolonged exposure of pigs to feed containing low levels of AFB1 inhibits growth, impairs digestive function, and disrupts the intestinal barrier by decreasing SOD activity and increasing the production of pro-inflammatory cytokines such as TNFα, IL1, and TGFβ. Cattle ingesting feed supplemented with AFB1 exhibited behavioral changes such as depression and anorexia, and necropsy reports in poisoned cattle showed hepatomegaly, enlarged gallbladder, and intestinal and renal congestion. AFB1 contamination of poultry feed reduces fertility, hatchability, chick weight, growth rate, productivity, and meat and egg quality, and increases susceptibility to disease and mortality.
Figure 1. Harmful effects of AFB1 on livestock and poultry
(Source: Li C, et al. 2022)
Alternative Names
AFB1 ELISA Kit
References
- 1. Li C, et al. Research progress in toxicological effects and mechanism of aflatoxin B1 toxin. PeerJ. 2022 Aug 4;10:e13850.
- 2. Gao X, et al. Aflatoxin B1-activated heterophil extracellular traps result in the immunotoxicity to liver and kidney in chickens. Dev Comp Immunol. 2022 Mar;128:104325.
References
Development of a risk-ranking framework to evaluate simultaneously biological and chemical hazards related to food safety: Application to emerging dietary practices in France
FOOD CONTROL
Authors: Eygue, Mounia; Richard-Forget, Florence; Cappelier, Jean-Michel; Pinson-Gadais, Laetitia; Membre, Jeanne-Marie
Abstract
The objective of this study was to develop a structured and transparent framework to rank emerging dietary practices. The first challenge was to rank simultaneously biological and chemical hazards using the same criteria whatever the nature of the hazard. For a list of dietary practices selected based on the results of a survey, hazard identification and health effect characterization was carried out. Taking only the top five practices led to the identification of 41 triplets "emerging dietary practice - hazard - health effect", which highlights the complexity of scoring risk in food safety. A wide variety of hazards, including microbes, parasites, mycotoxins, allergens and other chemical compounds were considered together with a range of health effects such as foodborne pathogen disease, anaphylaxis, cancer, immunosuppression, endocrine disturbance, etc. The second challenge was to develop a framework easy to populate and run. The risk-ranking framework included eight criteria: five to describe the severity, three to describe the likelihood. All of them were informed by literature data and food safety agencies' reports, plus experts' opinion. The PROMETHEE outranking MCDA technique, available in a R package, was implemented. This risk-ranking framework applied to the results of our small-scale survey revealed that consuming nuts on a regular basis could be the emerging dietary habit presenting the highest-risk score, due to the aflatoxin B1 hazard and its associated health effect (liver cancer). This risk-ranking framework requires however to be applied furthermore in other contexts to evaluate its robustness and identify opportunities for improvement. Once consolidated, this framework will be highly relevant for food safety authorities and policy makers to move forward transparent and evidence-informed decisions.
Synthesized Geopolymers Adsorb Bacterial Proteins, Toxins, and Cells
FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY
Authors: Popovich, John; Chen, Shaojiang; Iannuzo, Natalie; Ganser, Collin; Seo, Dong-Kyun; Haydel, Shelley E.
Abstract
Pore-forming and hemolytic toxins are bacterial cytotoxic proteins required for virulence in many pathogens, including staphylococci and streptococci, and are notably associated with clinical manifestations of disease. Inspired by adsorption properties of naturally occurring aluminosilicates, we engineered inexpensive, laboratory-synthesized, aluminosilicate geopolymers with controllable pore and surface characteristics to remove pathogenic or cytotoxic material from the surrounding environment. In this study, macroporous and mesoporous geopolymers were produced with and without stearic acid surface modifications. Geopolymer binding efficacies were assessed by measuring adsorption of methicillin-resistantStaphylococcus aureus(MRSA) culture filtrate proteins, alpha-hemolysin and streptolysin-O toxins, MRSA whole cells, and antibiotics. Macroporous and mesoporous geopolymers were strong non-selective adsorbents for bacterial protein, protein toxins, and bacteria. Although some geopolymers adsorbed antibiotics, these synthesized geopolymers could potentially be used in non-selective adsorptive applications and optimized for adsorption of specific biomolecules.
COA
Publication 
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