Biodiversity of Aflatoxigenic Aspergillus section Flavi Species According to Food Matrices and Geographic Areas

International audienceAflatoxins (AFs) are polyketide-derived metabolites produced by fungi on a wide range of crops (cereals, oilseeds, tree nuts, spices, dried fruits, etc.), both in the field and the post-harvest. As chemical stable molecules, resistant to conventional thermal or technological processes, they will pass through the whole food or feed supply chain to the final processed products. There are more than 20 known AFs and derivatives, yet the most hazardous AFs include the four naturally-occurring AFB1, AFB2, AFG1 and AFG2, and the hydroxylated metabolites of AFB1 and AFB2, and AFM1 and AFM2, which are produced through biotransformation in the liver and excreted in the milk of humans and mammals. AFs are known for their high acute and chronic toxicity to both humans and animals, and are considered among the most dangerous mycotoxins with carcinogenic, hepatotoxic, immunotoxic, teratogenic and mutagenic effects. AFB1 is the most prevalent and toxic aflatoxin, and is classified as a Group 1 human carcinogens. The intake of high amounts of AFs can cause acute intoxication (aflatoxicosis) associated with jaundice, vomiting, hemorrhages, abdominal pain, acute liver failure, problems with absorption of nutrients, and can be lethal. Reported outbreaks in western India (1974) and in Kenya (2004) caused the death of 106 and 125 people, respectively. Chronic exposure to low levels of AFs is associated with high risk of hepatocellular carcinoma (HCC), immunosuppression, teratogenic and mutagenic effects, reduction of nutrient absorption, child stunting, detrimental effects in the endocrinal system, and liver failure. More than five billion people worldwide are at risk of chronic exposure to AFs through contaminated foods. Humans’ exposure to AFs mainly occurs by direct intake of contaminated foods of vegetal or animal origin. Hence, the presence of AFs in foodstuff and feedstuff is a public health issue associated with detrimental effects in economy. In addition, commodities are generally contaminated by several mycotoxins, and this co-occurrence may result in a greater toxicity to humans caused by the possible additive or synergistic effects of these compounds. The main aflatoxin-producing fungi belong to Aspergillus section Flavi of the Circumdati subgenus, and only five AF producers do not belong to this section, A. ochraceoroseus, A. rambellii (A. section Ochraceorosei), A. astellatus, A. olivicola, and A. venezuelensis (A. section Nidulantes). The aim of the present chapter is to describe the characteristics of the aflatoxigenic Aspergillus section Flavi species isolated from food or feed, and to address the biodiversity according to food matrices and geographic areas

Biodiversity of Aflatoxigenic Aspergillus section Flavi Species According to Food Matrices and Geographic Areas

International audienceAflatoxins (AFs) are polyketide-derived metabolites produced by fungi on a wide range of crops (cereals, oilseeds, tree nuts, spices, dried fruits, etc.), both in the field and the post-harvest. As chemical stable molecules, resistant to conventional thermal or technological processes, they will pass through the whole food or feed supply chain to the final processed products. There are more than 20 known AFs and derivatives, yet the most hazardous AFs include the four naturally-occurring AFB1, AFB2, AFG1 and AFG2, and the hydroxylated metabolites of AFB1 and AFB2, and AFM1 and AFM2, which are produced through biotransformation in the liver and excreted in the milk of humans and mammals. AFs are known for their high acute and chronic toxicity to both humans and animals, and are considered among the most dangerous mycotoxins with carcinogenic, hepatotoxic, immunotoxic, teratogenic and mutagenic effects. AFB1 is the most prevalent and toxic aflatoxin, and is classified as a Group 1 human carcinogens. The intake of high amounts of AFs can cause acute intoxication (aflatoxicosis) associated with jaundice, vomiting, hemorrhages, abdominal pain, acute liver failure, problems with absorption of nutrients, and can be lethal. Reported outbreaks in western India (1974) and in Kenya (2004) caused the death of 106 and 125 people, respectively. Chronic exposure to low levels of AFs is associated with high risk of hepatocellular carcinoma (HCC), immunosuppression, teratogenic and mutagenic effects, reduction of nutrient absorption, child stunting, detrimental effects in the endocrinal system, and liver failure. More than five billion people worldwide are at risk of chronic exposure to AFs through contaminated foods. Humans’ exposure to AFs mainly occurs by direct intake of contaminated foods of vegetal or animal origin. Hence, the presence of AFs in foodstuff and feedstuff is a public health issue associated with detrimental effects in economy. In addition, commodities are generally contaminated by several mycotoxins, and this co-occurrence may result in a greater toxicity to humans caused by the possible additive or synergistic effects of these compounds. The main aflatoxin-producing fungi belong to Aspergillus section Flavi of the Circumdati subgenus, and only five AF producers do not belong to this section, A. ochraceoroseus, A. rambellii (A. section Ochraceorosei), A. astellatus, A. olivicola, and A. venezuelensis (A. section Nidulantes). The aim of the present chapter is to describe the characteristics of the aflatoxigenic Aspergillus section Flavi species isolated from food or feed, and to address the biodiversity according to food matrices and geographic areas

Biodiversity of Aflatoxigenic Aspergillus section Flavi Species According to Food Matrices and Geographic Areas

International audienceAflatoxins (AFs) are polyketide-derived metabolites produced by fungi on a wide range of crops (cereals, oilseeds, tree nuts, spices, dried fruits, etc.), both in the field and the post-harvest. As chemical stable molecules, resistant to conventional thermal or technological processes, they will pass through the whole food or feed supply chain to the final processed products. There are more than 20 known AFs and derivatives, yet the most hazardous AFs include the four naturally-occurring AFB1, AFB2, AFG1 and AFG2, and the hydroxylated metabolites of AFB1 and AFB2, and AFM1 and AFM2, which are produced through biotransformation in the liver and excreted in the milk of humans and mammals. AFs are known for their high acute and chronic toxicity to both humans and animals, and are considered among the most dangerous mycotoxins with carcinogenic, hepatotoxic, immunotoxic, teratogenic and mutagenic effects. AFB1 is the most prevalent and toxic aflatoxin, and is classified as a Group 1 human carcinogens. The intake of high amounts of AFs can cause acute intoxication (aflatoxicosis) associated with jaundice, vomiting, hemorrhages, abdominal pain, acute liver failure, problems with absorption of nutrients, and can be lethal. Reported outbreaks in western India (1974) and in Kenya (2004) caused the death of 106 and 125 people, respectively. Chronic exposure to low levels of AFs is associated with high risk of hepatocellular carcinoma (HCC), immunosuppression, teratogenic and mutagenic effects, reduction of nutrient absorption, child stunting, detrimental effects in the endocrinal system, and liver failure. More than five billion people worldwide are at risk of chronic exposure to AFs through contaminated foods. Humans’ exposure to AFs mainly occurs by direct intake of contaminated foods of vegetal or animal origin. Hence, the presence of AFs in foodstuff and feedstuff is a public health issue associated with detrimental effects in economy. In addition, commodities are generally contaminated by several mycotoxins, and this co-occurrence may result in a greater toxicity to humans caused by the possible additive or synergistic effects of these compounds. The main aflatoxin-producing fungi belong to Aspergillus section Flavi of the Circumdati subgenus, and only five AF producers do not belong to this section, A. ochraceoroseus, A. rambellii (A. section Ochraceorosei), A. astellatus, A. olivicola, and A. venezuelensis (A. section Nidulantes). The aim of the present chapter is to describe the characteristics of the aflatoxigenic Aspergillus section Flavi species isolated from food or feed, and to address the biodiversity according to food matrices and geographic areas

Multi-mycotoxin determination in rice, maize and peanut products most consumed in Côte d'Ivoire by UHPLC-MS/MS

The aim of this study was to determine the multi-mycotoxin occurrence in cereal and oilseed products most consumed in Côte d'Ivoire. A total of 238 samples of rice (88 produced locally or imported), maize (79, cracked or flour) and peanut paste (71) were collected in the main markets of Abidjan, Bouaké and Korhogo. An UHPLC-MS/MS method allowed the analysis of 77 mycotoxins. All the peanut paste samples were contaminated by aflatoxin B1 (AFB1) with 99% exceeding the EU limits of 2 μg kg−1 for AFB1 and 4 μg kg−1 for total aflatoxins (AFT: B1+B2+G1+G2), and concentrations reaching up to 4535 μg kg−1 (AFB1) and 8094 μg kg−1 (AFT). Maize (96%) and rice (57%) samples were also contaminated by AFB1 with 58% and 24% respectively above the EU limits and maximum levels of 80 μg kg−1 for maize and 14 μg kg−1 for rice. Only 6% of the cereal samples (3 rice and one maize samples) had ochratoxin A content above the EU limit (3 μg kg−1). Fumonisins and zearalenone were detected, respectively, in 91% and 8% of the maize samples, and in 18% and 5% of the rice samples but at levels below EU limits. Out of the 238 samples, 91% were contaminated with more than one mycotoxin including EU regulated mycotoxins and/or other mycotoxins mainly beauvericin (79% of the samples), equisetin (71%), aflatoxin M1 (45%), cyclopiazonic acid (32%), fumonisin B3 (29%), sterigmatocystin (24%), citrinin (18%), ochratoxin B (16%) and fusaric acid (15%). The peanut paste samples represented the highest risk to consumer health followed by maize and rice samples. (Résumé d'auteur

Aspergillus korhogoensis, a Novel Aflatoxin Producing Species from the Côte d’Ivoire

Several strains of a new aflatoxigenic species of Aspergillus, A. korhogoensis, were isolated in the course of a screening study involving species from section Flavi found contaminating peanuts (Arachis hypogaea) and peanut paste in the Côte d’Ivoire. Based on examination of four isolates, this new species is described using a polyphasic approach. A concatenated alignment comprised of nine genes (ITS, benA, cmdA, mcm7, amdS, rpb1, preB, ppgA, and preA) was subjected to phylogenetic analysis, and resulted in all four strains being inferred as a distinct clade. Characterization of mating type for each strain revealed A. korhogoensis as a heterothallic species, since three isolates exhibited a singular MAT1-1 locus and one isolate exhibited a singular MAT1-2 locus. Morphological and physiological characterizations were also performed based on their growth on various types of media. Their respective extrolite profiles were characterized using LC/HRMS, and showed that this new species is capable of producing B- and G-aflatoxins, aspergillic acid, cyclopiazonic acid, aflavarins, and asparasones, as well as other metabolites. Altogether, our results confirm the monophyly of A. korhogoensis, and strengthen its position in the A. flavus clade, as the sister taxon of A. parvisclerotigenus