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Atoui A.,Lebanese Atomic Energy Commission CNRS | El Khoury A.,Saint - Joseph University | Kallassy M.,Saint - Joseph University | Lebrihi A.,National Graduate School of Agronomy, Toulouse
International Journal of Food Microbiology | Year: 2012

Zearalenone (ZEA) is a mycotoxin produced by some species of Fusarium, especially by Fusarium graminearum and F. culmorum. ZEA induces hyperoestrogenic responses in mammals and can result in reproductive disorders in farm animals. In the present study, a real-time PCR (qPCR) assay has been successfully developed for the detection and quantification of Fusarium graminearum based on primers targeting the gene PKS13 involved in ZEA biosynthesis. A standard curve was developed by plotting the logarithm of known concentrations of F. graminearum DNA against the cycle threshold (Ct) value. The developed real time PCR system was also used to analyze the occurrence of zearalenone producing F. graminearum strains on maize. In this context, DNA extractions were performed from thirty-two maize samples, and subjected to real time PCR. Maize samples also were analyzed for zearalenone content by HPLC. F. graminearum DNA content (pg DNA/ mg of maize) was then plotted against ZEA content (ppb) in maize samples. The regression curve showed a positive and good correlation (R 2=0.760) allowing for the estimation of the potential risk from ZEA contamination. Consequently, this work offers a quick alternative to conventional methods of ZEA quantification and mycological detection and quantification of F. graminearum in maize. © 2011.


El Khoury A.,Saint - Joseph University | Atoui A.,Lebanese Atomic Energy Commission CNRS | Rizk T.,Saint - Joseph University | Lteif R.,Saint - Joseph University | And 2 more authors.
Journal of Food Science | Year: 2011

Aflatoxins (AFs) represent the most important single mycotoxin-related food safety problem in developed and developing countries as they have adverse effects on human and animal health. They are produced mainly byAspergillus flavusandA. parasiticus. Both species have different aflatoxinogenic profile. In order to distinguish betweenA. flavusandA. parasiticus, gene-specific primers were designed to target the intergenic spacer (IGS) for the AF biosynthesis genes,aflJandaflR. Polymerase chain reaction (PCR) products were subjected to restriction endonuclease analysis usingBglIIto look for restriction fragment length polymorphisms (RFLPs). Our result showed that both species displayed different PCR-based RFLP (PCR-RFLP) profile. PCR products fromA. flavuscleaved into 3 fragments of 362, 210, and 102 bp. However, there is only one restriction site for this enzyme in the sequence ofA. parasiticusthat produced only 2 fragments of 363 and 311 bp. The method was successfully applied to contaminated grapes samples. This approach of differentiating these 2 species would be simpler, less costly, and quicker than conventional sequencing of PCR products and/or morphological identification. © 2011 Institute of Food Technologists®.


el Khoury A.E.,Saint - Joseph University | Atoui A.,Lebanese Atomic Energy Commission CNRS
Toxins | Year: 2010

Ochratoxin A (OTA) is a mycotoxin produced by several species of Aspergillus and Penicillium fungi that structurally consists of a para-chlorophenolic group containing a dihydroisocoumarin moiety that is amide-linked to L-phenylalanine. OTA is detected worldwide in various food and feed sources. Studies show that this molecule can have several toxicological effects such as nephrotoxic, hepatotoxic, neurotoxic, teratogenic and immunotoxic. A role in the etiology of Balkan endemic nephropathy and its association to urinary tract tumors has been also proved. In this review, we will explore the general aspect of OTA: physico-chemical properties, toxicological profile, OTA producing fungi, contaminated food, regulation, legislation and analytical methods. Due to lack of sufficient information related to the molecular background, this paper will discuss in detail the recent advances in molecular biology of OTA biosynthesis, based on information and on new data about identification and characterization of ochratoxin biosynthetic genes in both Penicillium and Aspergillus species. This review will also cover the development of the molecular methods for the detection and quantification of OTA producing fungi in various foodstuffs. © 2010 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.


Slim K.,Lebanese Atomic Energy Commission CNRS | Fadel A.,Lebanese Atomic Energy Commission CNRS | Fadel A.,ParisTech National School of Bridges and Roads | Atoui A.,Lebanese Atomic Energy Commission CNRS | And 4 more authors.
Desalination and Water Treatment | Year: 2014

The Middle East region suffers already from the gradual effects of climate change and will be among the most vulnerable regions in the future. As a result, productivity should undergo losses due to high temperatures, drought, floods, and soil degradation which threaten food security of Levantine countries. Since water is the critical factor in the region, even slight changes in air temperature and rainfall patterns will have considerable impact. It has been proven that potential climate change may disrupt, on one hand, most ecosystems through changes in their physicochemical conditions, and on the other hand the species which are living in these ecosystems. Then, the biodiversity can be found challenging. In this study, the effects of climate change on population and phytoplankton communities of Lake Karaoun were investigated since 1992. The climate regime shifts have been shown to alter the lake ecosystem. In the past, Lake Karaoun was characterized by a highly diversified microflora dominated by diatoms and green algae. Recent climatic fluctuations, with culmination in 2008-2011 and temperatures exceeding 40°C have upset this biodiversity. Blooms of cyanobacteria, specifically Microcystis aeruginosa and Aphanizomenon ovalisporum, have occurred and disturbed both the ecosystem and the functioning of the lake. © 2013 Balaban Desalination Publications.


Fadel A.,Lebanese Atomic Energy Commission CNRS | Fadel A.,ParisTech National School of Bridges and Roads | Atoui A.,Lebanese Atomic Energy Commission CNRS | Lemaire B.J.,ParisTech National School of Bridges and Roads | And 3 more authors.
Toxins | Year: 2014

Chrysosporum ovalisporum is a cylindrospermopsin toxin producing cyanobacterium that was reported in several lakes and reservoirs. Its growth dynamics and toxin distribution in field remain largely undocumented. Chrysosporum ovalisporum was reported in 2009 in Karaoun Reservoir, Lebanon. We investigated the factors controlling the occurrence of this cyanobacterium and vertical distribution of cylindrospermopsin in Karaoun Reservoir. We conducted bi-weekly sampling campaigns between May 2012 and August 2013. Results showed that Chrysosporum ovalisporum is an ecologically plastic species that was observed in all seasons. Unlike the high temperatures, above 26 °C, which is associated with blooms of Chrysosporum ovalisporum in Lakes Kinneret (Israel), Lisimachia and Trichonis (Greece) and Arcos Reservoir (Spain), Chrysosporum ovalisporum in Karaoun Reservoir bloomed in October 2012 at a water temperature of 22 °C during weak stratification. Cylindrospermopsin was detected in almost all water samples even when Chrysosporum ovalisporum was not detected. Chrysosporum ovalisporum biovolumes and cylindrospermopsin concentrations were not correlated (n = 31, r2= −0.05). Cylindrospermopsin reached a maximum concentration of 1.7 μg L−1. The vertical profiles of toxin concentrations suggested its possible degradation or sedimentation resulting in its disappearance from the water column. The field growth conditions of Chrysosporum ovalisporum in this study revealed that it can bloom at the subsurface water temperature of 22 °C increasing the risk of its development and expansion in lakes located in temperate climate regions. © 2014 by the authors; licensee MDPI, Basel, Switzerland.


Rioult D.,University of Le Havre | Pasquier J.,University of Le Havre | Boulange-Lecomte C.,University of Le Havre | Poret A.,University of Le Havre | And 4 more authors.
Aquatic Toxicology | Year: 2014

In marine and estuarine species, immunotoxic and/or immunomodulatory mechanisms are the crossroad of interactions between xenobiotics, microorganisms and physicochemical variations of the environment. In mussels, immunity relies exclusively on innate responses carried out by cells collectively called hemocytes and found in the open hemolymphatic circulatory system of these organisms. However, hemocytes do not form a homogenous population of immune cells since distinct subtypes of mussel blood cells can be distinguished by cytochemistry, flow cytometry or cell motility analysis. Previous studies have also shown that these cells are able to efflux xenobiotics by means of ATP binding cassette (ABC) transporter activities conferring a multixenobiotic resistance (MXR) phenotype. ABC transporters corresponding to vertebrate class B/P-glycoprotein (P-gp) and to class C/multidrug resistance related protein (MRP) are characterized in Mytilidae. Herein, we have investigated the relative contributions of ABCB- and ABCC-mediated efflux within the different hemocyte subpopulations of Mytilus edulis mussels, collected from areas differentially impacted by chemical contaminants in Normandy (France). RT-PCR analyses provide evidence for the presence of ABCB and ABCC transporters transcripts in hemocytes. Immunodetection of ABCB/P-gp with the monoclonal antibody UIC2 in living hemocytes revealed that expression was restricted to granular structures of spread cells. Efflux transporter activities, with calcein-AM as fluorescent probe, were measured by combining flow cytometry to accurate Coulter cell size measurements in order to get a cell-volume normalized fluorescence concentration. In these conditions, basal fluorescence levels were higher in hemocytes originating from Yport (control site) than in cells collected from the harbor of Le Havre, where mussels are more exposed to with persistent pollutants. By using specific ABCB/P-gp (verapamil, PSC833, zosuquidar) and ABCC/MRP (MK571) blockers, we show that MXR activity is only carried out by MRP-type transporters in M. edulis hemocytes. In addition, cell-type-gated flow cytometry and calculation of the MXR activity factor indicate that ABCC-efflux activity is higher and more inducible in eosinophilic granulocytes than in other hemocyte subtypes. We conclude that, in the hemocytes of M. edulis, MXR phenotype is mediated by an ABCC/MRP-type transporter activity principally supported by eosinophilic granulocytes. A role for ABC transporters in hemocyte migration is discussed. © 2013 Elsevier B.V.


PubMed | University Paul Sabatier, Saint - Joseph University and Lebanese Atomic Energy Commission CNRS
Type: | Journal: International journal of food microbiology | Year: 2014

Patulin is a polyketide-derived mycotoxin produced by numerous filamentous fungi. Among them, Penicillium expansum is by far the most problematic species. This fungus is a destructive phytopathogen capable of growing on fruit, provoking the blue mold decay of apples and producing significant amounts of patulin. The biosynthetic pathway of this mycotoxin is chemically well-characterized, but its genetic bases remain largely unknown with only few characterized genes in less economic relevant species. The present study consisted of the identification and positional organization of the patulin gene cluster in P. expansum strain NRRL 35695. Several amplification reactions were performed with degenerative primers that were designed based on sequences from the orthologous genes available in other species. An improved genome Walking approach was used in order to sequence the remaining adjacent genes of the cluster. RACE-PCR was also carried out from mRNAs to determine the start and stop codons of the coding sequences. The patulin gene cluster in P. expansum consists of 15 genes in the following order: patH, patG, patF, patE, patD, patC, patB, patA, patM, patN, patO, patL, patI, patJ, and patK. These genes share 60-70% of identity with orthologous genes grouped differently, within a putative patulin cluster described in a non-producing strain of Aspergillus clavatus. The kinetics of patulin cluster genes expression was studied under patulin-permissive conditions (natural apple-based medium) and patulin-restrictive conditions (Eagles minimal essential medium), and demonstrated a significant association between gene expression and patulin production. In conclusion, the sequence of the patulin cluster in P. expansum constitutes a key step for a better understanding of the mechanisms leading to patulin production in this fungus. It will allow the role of each gene to be elucidated, and help to define strategies to reduce patulin production in apple-based products.


PubMed | American University of Beirut and Lebanese Atomic Energy Commission CNRS
Type: Journal Article | Journal: Environmental monitoring and assessment | Year: 2016

This study assesses the dietary exposure of Lebanese adults to 47 pesticide residues from both foods of plant origin and drinks. The study was conducted using the Total Diet Study protocol in two different areas of Lebanon: Greater Beirut (urban) and Keserwan (semi-rural). A total of 1860 individual foods were collected, prepared, and cooked prior to analysis. Composite samples of similar foods were analyzed, following the QuEChERS Multiresidue method. Eighteen residues were detected/quantified on at least one composite sample, with 66.7% of the results being quantifiable and 33.3% detectable. Quantifiable levels ranged between 10.3 and 208g/kg. For the composite samples where residues were detected, 55% had one residue, while 45% had 2-4 residues. The most frequently detected/quantified pesticide residues included Chlorpyrifos, Procymidone, Primiphos methyl, Dimethoate, and Dieldrin. The dietary exposure assessment was conducted using the deterministic approach with two scenarios: (1) the lower bound (LB) approach and (2) the upper bound (UB) approach. Using the LB approach, mean estimated daily exposures were far below the acceptable daily intakes (ADIs) for all investigated residues. Using the UB approach, which tends to overestimate exposure, mean estimated daily exposures were below the ADIs for all residues except for Dieldrin (semi-rural: 128.7% ADI; urban: 100.7% ADI). Estimates of mean exposure to Diazinon reached 50.3% of ADI in the urban diet and 61.9% in the semi-rural diet. Findings of this study identify specific pesticide residues as monitoring priorities for which more comprehensive and sensitive analyses are needed in order to refine exposure assessment.


PubMed | Lille University of Science and Technology, University of Le Havre and Lebanese Atomic Energy Commission CNRS
Type: | Journal: Aquatic toxicology (Amsterdam, Netherlands) | Year: 2014

In marine and estuarine species, immunotoxic and/or immunomodulatory mechanisms are the crossroad of interactions between xenobiotics, microorganisms and physicochemical variations of the environment. In mussels, immunity relies exclusively on innate responses carried out by cells collectively called hemocytes and found in the open hemolymphatic circulatory system of these organisms. However, hemocytes do not form a homogenous population of immune cells since distinct subtypes of mussel blood cells can be distinguished by cytochemistry, flow cytometry or cell motility analysis. Previous studies have also shown that these cells are able to efflux xenobiotics by means of ATP binding cassette (ABC) transporter activities conferring a multixenobiotic resistance (MXR) phenotype. ABC transporters corresponding to vertebrate class B/P-glycoprotein (P-gp) and to class C/multidrug resistance related protein (MRP) are characterized in Mytilidae. Herein, we have investigated the relative contributions of ABCB- and ABCC-mediated efflux within the different hemocyte subpopulations of Mytilus edulis mussels, collected from areas differentially impacted by chemical contaminants in Normandy (France). RT-PCR analyses provide evidence for the presence of ABCB and ABCC transporters transcripts in hemocytes. Immunodetection of ABCB/P-gp with the monoclonal antibody UIC2 in living hemocytes revealed that expression was restricted to granular structures of spread cells. Efflux transporter activities, with calcein-AM as fluorescent probe, were measured by combining flow cytometry to accurate Coulter cell size measurements in order to get a cell-volume normalized fluorescence concentration. In these conditions, basal fluorescence levels were higher in hemocytes originating from Yport (control site) than in cells collected from the harbor of Le Havre, where mussels are more exposed to with persistent pollutants. By using specific ABCB/P-gp (verapamil, PSC833, zosuquidar) and ABCC/MRP (MK571) blockers, we show that MXR activity is only carried out by MRP-type transporters in M. edulis hemocytes. In addition, cell-type-gated flow cytometry and calculation of the MXR activity factor indicate that ABCC-efflux activity is higher and more inducible in eosinophilic granulocytes than in other hemocyte subtypes. We conclude that, in the hemocytes of M. edulis, MXR phenotype is mediated by an ABCC/MRP-type transporter activity principally supported by eosinophilic granulocytes. A role for ABC transporters in hemocyte migration is discussed.


PubMed | Lebanese Atomic Energy Commission CNRS and University Paris Est Creteil
Type: Journal Article | Journal: Environmental monitoring and assessment | Year: 2015

Eutrophication and harmful algal blooms have become a worldwide environmental problem. Understanding the mechanisms and processes that control algal blooms is of great concern. The phytoplankton community of Karaoun Reservoir, the largest water body in Lebanon, is poorly studied, as in many freshwater bodies around the Mediterranean Sea. Sampling campaigns were conducted semi-monthly between May 2012 and August 2013 to assess the dynamics of its phytoplankton community in response to changes in physical-chemical and hydrological conditions. Karaoun Reservoir is a monomictic waterbody and strongly stratifies between May and August. Changes in its phytoplankton community were found to be a result of the interplay between water temperature, stratification, irradiance, nutrient availability and water level. Thermal stratification established in spring reduced the growth of diatoms and resulted in their replacement by green algae species when nutrient availability was high and water temperatures lower than 22C. At water temperature higher than 25C and low nutrient concentrations in summer, blooms of the cyanobacterium Microcystis aeruginosa occurred. Despite different growth conditions in other lakes and reservoir, cyanobacterium Aphanizomenon ovalisporum dominated at temperatures lower than 23C in weakly stratified conditions in early autumn and dinoflagellate Ceratium hirundinella dominated in mixed conditions, at low light intensity and a water temperature of 19C in late autumn. We believe that the information presented in this paper will increase the knowledge about phytoplankton dynamics in the Mediterranean region and contribute to a safer usage of reservoir waters.

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