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B-cell lymphoblastic lymphoma (LBL) is a highly aggressive malignant proliferation of lymphoblasts of B-origin grouped with acute lymphoblastic leukemia. Multiple studies demonstrated the various sites of involvement in adult LBL. The... more
B-cell lymphoblastic lymphoma (LBL) is a highly aggressive malignant proliferation of lymphoblasts of B-origin grouped with acute lymphoblastic leukemia. Multiple studies demonstrated the various sites of involvement in adult LBL. The involvement of the uterus as a site of relapse for such disease is rare. We herein report the case of relapsed B-cell LBL mimicking endometrial sarcoma. The patient is a 56-year-old female patient known to have B-cell LBL on chemotherapy. She presented with abdominal pain and fever. Positron emission tomodensitometry-computed tomography showed the presence of a uterine mass with bilateral iliac lymph node involvement. She underwent surgery with mass removal and pathology showed relapsed B-cell LBL.
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The study of fungal species evolved radically with the development of molecular techniques and produced new evidence to understand specific fungal mechanisms such as the production of toxic secondary metabolites. Taking advantage of these... more
The study of fungal species evolved radically with the development of molecular techniques and produced new evidence to understand specific fungal mechanisms such as the production of toxic secondary metabolites. Taking advantage of these technologies to improve food safety, the molecular study of toxinogenic species can help elucidate the mechanisms underlying toxin production and enable the development of new effective strategies to control fungal toxicity. Numerous studies have been made on genes involved in aflatoxin B1 (AFB1) production, one of the most hazardous carcinogenic toxins for humans and animals. The current review presents the roles of these different genes and their possible impact on AFB1 production. We focus on the toxinogenic strains Aspergillus flavus and A. parasiticus, primary contaminants and major producers of AFB1 in crops. However, genetic reports on A. nidulans are also included because of the capacity of this fungus to produce sterigmatocystin, the penul...
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Aflatoxins (AF) are carcinogenic metabolites produced by different species of Aspergillus which readily colonize crops. AFM1 is secreted in the milk of lactating mammals through the ingestion of feedstuffs contaminated by aflatoxin B1... more
Aflatoxins (AF) are carcinogenic metabolites produced by different species of Aspergillus which readily colonize crops. AFM1 is secreted in the milk of lactating mammals through the ingestion of feedstuffs contaminated by aflatoxin B1 (AFB1). Therefore, its presence in milk, even in small amounts, presents a real concern for dairy industries and consumers of dairy products. Different strategies can lead to the reduction of AFM1 contamination levels in milk. They include adopting good agricultural practices, decreasing the AFB1 contamination of animal feeds, or using diverse types of adsorbent materials. One of the most effective types of adsorbents used for AFM1 decontamination are those of microbial origin. This review discusses current issues about AFM1 decontamination methods. These methods are based on the use of different bio-adsorbent agents such as bacteria and yeasts to complex AFM1 in milk. Moreover, this review answers some of the raised concerns about the binding stabilit...
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This study is intended to prevent ochratoxin A (OTA) production by Aspergillus carbonarius S402 using essential oils (EOs) and total phenolic compounds extracted from plants and herbs. The EOs used in this study are the following: bay... more
This study is intended to prevent ochratoxin A (OTA) production by Aspergillus carbonarius S402 using essential oils (EOs) and total phenolic compounds extracted from plants and herbs. The EOs used in this study are the following: bay leaves, cumin, fenugreek, melissa, mint, and sage. As for the phenolic compounds, they were extracted from bay leaves, cumin, fenugreek, melissa, mint, sage, anise, chamomile, fennel, rosemary, and thyme. The experiments were conducted on Synthetic Grape Medium (SGM) medium at 28 °C for 4 days. OTA was extracted from the medium with methanol and quantified using HPLC (High Performance Liquid Chromatography). Results showed that EOs had a greater impact than the total phenolic extracts on the OTA production. Reduction levels ranged between 25% (sage) and 80% (melissa) for the EOs at 5 µL mL(-1), and 13% (thyme) and 69% (mint) for the phenolic extracts. Although they did not affect the growth of A. carbonarius, total phenolic extracts and EOs were capabl...
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Ochratoxin A (OTA) is one of the most important mycotoxins, and contaminates several agricultural products, particularly cereals, grapes, maize, barley, spices and coffee. The aim of this project was to reduce the levels of OTA by... more
Ochratoxin A (OTA) is one of the most important mycotoxins, and contaminates several agricultural products, particularly cereals, grapes, maize, barley, spices and coffee. The aim of this project was to reduce the levels of OTA by supplementing the artificially contaminated solutions with seven strains of actinobacteria (AT10, AT8, SN7, MS1, ML5, G10 and PT1) in order to evaluate their capacity for binding and metabolizing the OTA, as well as their ability to reduce the expression of the genes responsible for its production in A. carbonarius. In the first part of this study, we evaluated the capacity of Streptomyces strains for binding OTA on their surfaces after 0, 30 and 60 min of incubation with PBS solution supplemented with OTA. In the second part, we tested the ability of these strains, as well as their supernatants, to detoxify the ISP2 medium. Finally, we studied the effect of the Streptomyces cocultured with Aspergillus carbonarius on the expression of OTA biosynthesis gene...
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Patulin is the main mycotoxin contaminating apples. During the brewing of alcoholic beverages, this mycotoxin is degraded to ascladiol, which is also the last precursor of patulin. The present study aims (1) to characterize the last step... more
Patulin is the main mycotoxin contaminating apples. During the brewing of alcoholic beverages, this mycotoxin is degraded to ascladiol, which is also the last precursor of patulin. The present study aims (1) to characterize the last step of the patulin biosynthetic pathway and (2) to describe the toxicity of ascladiol. A patE deletion mutant was generated in Penicillium expansum. In contrast to the wild strain, this mutant does not produce patulin but accumulates high levels of E-ascladiol with few traces of Z-ascladiol. This confirms that patE encodes the patulin synthase involved in the conversion of E-ascladiol to patulin. After purification, cytotoxicities of patulin and E- and Z-ascladiol were investigated on human cell lines from liver, kidney, intestine, and immune system. Patulin was cytotoxic for these four cell lines in a dose-dependent manner. By contrast, both E- and Z-ascladiol were devoid of cytotoxicity. Microarray analyses on human intestinal cells treated with patul...
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Produced by several species of Aspergillus, Aflatoxin B₁ (AFB₁) is a carcinogenic mycotoxin contaminating many crops worldwide. The utilization of fungicides is currently one of the most common methods; nevertheless, their use is not... more
Produced by several species of Aspergillus, Aflatoxin B₁ (AFB₁) is a carcinogenic mycotoxin contaminating many crops worldwide. The utilization of fungicides is currently one of the most common methods; nevertheless, their use is not environmentally or economically sound. Thus, the use of natural compounds able to block aflatoxinogenesis could represent an alternative strategy to limit food and feed contamination. For instance, eugenol, a 4-allyl-2-methoxyphenol present in many essential oils, has been identified as an anti-aflatoxin molecule. However, its precise mechanism of action has yet to be clarified. The production of AFB₁ is associated with the expression of a 70 kB cluster, and not less than 21 enzymatic reactions are necessary for its production. Based on former empirical data, a molecular tool composed of 60 genes targeting 27 genes of aflatoxin B₁ cluster and 33 genes encoding the main regulatory factors potentially involved in its production, was developed. We showed t...
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... Noureddine et André, Phong, Gamal, Abdelgani, Awanwee, Hend, Hanane, Muriel, Rafik, Michael, Nina, Caroline, Anne claire, Slim, Nafees, Echarki, Virginie, Mariana, Amar, Boubakeur, Atar, Hadjira, Noura, Farida, Sandra, Ikram, Emilie... more
... Noureddine et André, Phong, Gamal, Abdelgani, Awanwee, Hend, Hanane, Muriel, Rafik, Michael, Nina, Caroline, Anne claire, Slim, Nafees, Echarki, Virginie, Mariana, Amar, Boubakeur, Atar, Hadjira, Noura, Farida, Sandra, Ikram, Emilie et Irène. ...
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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... more
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 (Eagle's 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.
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Research Interests: Chemical Engineering, Food Science, Molecular Biology, Food, Transcription Factors, and 15 moreFood Microbiology, Aspergillus, PCR, Analysis, Polymerase Chain Reaction, Differentiation, Aflatoxin, Aspergillus flavus, Aflatoxins, Mycotoxin, Food Contamination, Food Sciences, Analisis, RFLP, and DNA binding proteins
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... Noureddine et André, Phong, Gamal, Abdelgani, Awanwee, Hend, Hanane, Muriel, Rafik, Michael, Nina, Caroline, Anne claire, Slim, Nafees, Echarki, Virginie, Mariana, Amar, Boubakeur, Atar, Hadjira, Noura, Farida, Sandra, Ikram, Emilie... more
... Noureddine et André, Phong, Gamal, Abdelgani, Awanwee, Hend, Hanane, Muriel, Rafik, Michael, Nina, Caroline, Anne claire, Slim, Nafees, Echarki, Virginie, Mariana, Amar, Boubakeur, Atar, Hadjira, Noura, Farida, Sandra, Ikram, Emilie et Irène. ...
Research Interests: Microbiology, Molecular Biology, Industrial Biotechnology, Food Microbiology, Quantitative analysis, and 15 moreAspergillus, real time PCR, Sequence alignment, Polymerase Chain Reaction, Gene, Real Time, DNA content, Gen, Mycotoxin, Food Contamination, Food Sciences, Quantitative Analysis, Ochratoxin A, Ochratoxins, and gene amplification
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Research Interests: Genetics, Microbiology, Kinetics, Plant Biology, Aspergillus, and 12 moreStreptomyces, Oxidoreductases, Secondary Metabolites, Molecular cloning, Fungal Genetics and Biology, Multienzyme complexes, Biological activity, Amino Acid Sequence, Fungal Genetics, Molecular Structure, Macrolides, and Molecular Sequence Data
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... Journal of Experimental Marine Biology and Ecology 2, 123. Chang, DHS Gauch, Jr., HG 1986 Multivariate analysis of plant communities and environmental factors in Ngari, Tibet. ... Davis, JC 1973 Statistics and Data Analysis in... more
... Journal of Experimental Marine Biology and Ecology 2, 123. Chang, DHS Gauch, Jr., HG 1986 Multivariate analysis of plant communities and environmental factors in Ngari, Tibet. ... Davis, JC 1973 Statistics and Data Analysis in Geology. John Wiley and Sons, New York, 550 pp. ...
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Light sensing is very important for organisms in all biological kingdoms to adapt to changing environmental conditions. It was discovered recently that plant-like phytochrome is involved in light sensing in the filamentous fungus... more
Light sensing is very important for organisms in all biological kingdoms to adapt to changing environmental conditions. It was discovered recently that plant-like phytochrome is involved in light sensing in the filamentous fungus Aspergillus nidulans [1]. Here, we show that ...
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Research Interests: Microbiology, Molecular Biology, Industrial Biotechnology, Food Microbiology, Quantitative analysis, and 15 moreAspergillus, real time PCR, Sequence alignment, Polymerase Chain Reaction, Gene, Real Time, DNA content, Gen, Mycotoxin, Food Contamination, Food Sciences, Quantitative Analysis, Ochratoxin A, Ochratoxins, and gene amplification
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The Aspergillus nidulans putative mitogen-activated protein kinase encoded by mpkB has a role in natural product biosynthesis. An mpkB mutant exhibited a decrease in sterigmatocystin gene expression and low mycotoxin levels. The mutation... more
The Aspergillus nidulans putative mitogen-activated protein kinase encoded by mpkB has a role in natural product biosynthesis. An mpkB mutant exhibited a decrease in sterigmatocystin gene expression and low mycotoxin levels. The mutation also affected the expression of genes involved in penicillin and terrequinone A synthesis. mpkB was necessary for normal expression of laeA, which has been found to regulate secondary metabolism gene clusters.
Research Interests: Pheromones, Regulation, Multidisciplinary, Applied, Applied Environmental Microbiology, and 8 moreNatural Product, Mitogen Activated Protein Kinase, Aspergillus Nidulans, Gene expression profiling, Sterigmatocystin, reverse transcriptase polymerase chain reaction, Mitogen- Activated Protein Kinases, and Penicillins
Aspergillus westerdijkiae is the main producer of several biologically active polyketide metabolites including isoasperlactone and asperlactone. A 5298 bp polyketide synthase gene “aomsas” has been cloned in Aspergillus westerdijkiae by... more
Aspergillus westerdijkiae is the main producer of several biologically active polyketide metabolites including isoasperlactone and asperlactone. A 5298 bp polyketide synthase gene “aomsas” has been cloned in Aspergillus westerdijkiae by using gene walking approach and RACE-PCR. The predicted amino acid sequence of aomsas shows an identity of 40–56% with different methylsalicylic acid synthase genes found in Byssochlamys nivea, P. patulum, A. terreus and Streptomyces viridochromogenes. Based on the reverse transcription PCR and kinetic secondary metabolites production studies, aomsas expression was found to be associated with the biosynthesis of isoasperlactone and asperlactone. Moreover an aomsas knockout mutant “aoΔmsas” of A. westerdijkiae, not only lost the capacity to produce isoasperlactone and asperlactone, but also 6-methylsalicylic acid. The genetically complemented mutant ao+msas restored the biosynthesis of all the missing metabolites. Chemical complementation through the ...
Research Interests: Genetics, Microbiology, Kinetics, Plant Biology, Aspergillus, and 12 moreStreptomyces, Oxidoreductases, Secondary Metabolites, Molecular cloning, Fungal Genetics and Biology, Multienzyme complexes, Biological activity, Amino Acid Sequence, Fungal Genetics, Molecular Structure, Macrolides, and Molecular Sequence Data
Ochratoxin A (OTA) is a potential nephrotoxic, teratogenic, immunogenic, hepatotoxic and carcinogenic mycotoxin, produced by Aspergillus westerdijkiae NRRL 3174. Herein we describe the characterization of a putative OTA-polyketide... more
Ochratoxin A (OTA) is a potential nephrotoxic, teratogenic, immunogenic, hepatotoxic and carcinogenic mycotoxin, produced by Aspergillus westerdijkiae NRRL 3174. Herein we describe the characterization of a putative OTA-polyketide synthase gene “aoks1”, cloned by using gene walking approach. The predicted amino acid sequence of the 2 kb clone display 34–60% similarities to different polyketide synthase genes including lovastatine biosynthesis gene “lovb” in A. terreus, compactin biosynthesis gene “mlcA” in Penicillium citrinum and OTA biosynthesis gene “otapksPN” in P. nordicum. Based on the reverse transcription PCR and kinetic secondary metabolites production studies, aoks1 expression was found to be associated with OTA biosynthesis. Further a mutant, in which the aoks1 gene was inactivated by Escherichia coli hygromycin B phosphotransferase gene, lost the capacity to produce OTA, but still producing mellein. To our knowledge this report describes for the first time characterizati...