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Zhou S, Ismail MAI, Aimanianda V, de Hoog GS, Kang Y, Ahmed SA. Aflatoxin profiles of Aspergillus flavus isolates in Sudanese fungal rhinosinusitis. Med Mycol 2024; 62:myae034. [PMID: 38578660 PMCID: PMC11040519 DOI: 10.1093/mmy/myae034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2024] [Revised: 03/26/2024] [Accepted: 04/04/2024] [Indexed: 04/06/2024] Open
Abstract
Aspergillus flavus is a commonly encountered pathogen responsible for fungal rhinosinusitis (FRS) in arid regions. The species is known to produce aflatoxins, posing a significant risk to human health. This study aimed to investigate the aflatoxin profiles of A. flavus isolates causing FRS in Sudan. A total of 93 clinical and 34 environmental A. flavus isolates were studied. Aflatoxin profiles were evaluated by phenotypic (thin-layer and high-performance chromatography) and genotypic methods at various temperatures and substrates. Gene expression of aflD and aflR was also analyzed. A total of 42/93 (45%) isolates were positive for aflatoxin B1 and AFB2 by HPLC. When the incubation temperature changed from 28°C to 36°C, the number of positive isolates decreased to 41% (38/93). Genetic analysis revealed that 85% (79/93) of clinical isolates possessed all seven aflatoxin biosynthesis-associated genes, while 27% (14/51) of non-producing isolates lacked specific genes (aflD/aflR/aflS). Mutations were observed in aflS and aflR genes across both aflatoxin-producers and non-producers. Gene expression of aflD and aflR showed the highest expression between the 4th and 6th days of incubation on the Sabouraud medium and on the 9th day of incubation on the RPMI (Roswell Park Memorial Institute) medium. Aspergillus flavus clinical isolates demonstrated aflatoxigenic capabilities, influenced by incubation temperature and substrate. Dynamic aflD and aflR gene expression patterns over time enriched our understanding of aflatoxin production regulation. The overall findings underscored the health risks of Sudanese patients infected by this species, emphasizing the importance of monitoring aflatoxin exposure.
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Affiliation(s)
- Shaoqin Zhou
- School of Public Health, Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education of Guizhou, Key Laboratory of Microbiology and Parasitology of Education Department of Guizhou, School of Basic Medical Science, Guizhou Medical University, 561113, Guiyang, China
- Radboudumc-CWZ Centre of Expertise for Mycology, 6525 GA, Nijmegen, The Netherlands
| | - Mawahib A I Ismail
- Mycology Reference Laboratory, University of Khartoum, 11115, Khartoum, Sudan
| | - Vishukumar Aimanianda
- Immunobiology of Aspergillus, Institut Pasteur, Universite ´ Paris Cite ´ 75015, Paris, France
| | - G Sybren de Hoog
- Radboudumc-CWZ Centre of Expertise for Mycology, 6525 GA, Nijmegen, The Netherlands
- Foundation Atlas of Clinical Fungi, 1214 GP, Hilversum, The Netherlands
| | - Yingqian Kang
- School of Public Health, Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education of Guizhou, Key Laboratory of Microbiology and Parasitology of Education Department of Guizhou, School of Basic Medical Science, Guizhou Medical University, 561113, Guiyang, China
| | - Sarah A Ahmed
- Radboudumc-CWZ Centre of Expertise for Mycology, 6525 GA, Nijmegen, The Netherlands
- Foundation Atlas of Clinical Fungi, 1214 GP, Hilversum, The Netherlands
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Tan S, Ma F, Wu Y, Xu Y, Niu A, Chen Y, Wang G, Qiu W. The biodiversity of Aspergillus flavus in stored rice grain leads to a decrease in the overall aflatoxin B 1 production in these species. Int J Food Microbiol 2023; 406:110416. [PMID: 37769398 DOI: 10.1016/j.ijfoodmicro.2023.110416] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 09/11/2023] [Accepted: 09/22/2023] [Indexed: 09/30/2023]
Abstract
Aspergillus flavus is a significant fungus that poses a threat to food safety by producing mycotoxins in various crops. In this study, A. flavus isolates were obtained from storage rice collected from seven provinces in southern China, and their AFB1 production, biosynthesis genes presence, and diversity were detected. Results showed that 56 out of the 81 A. flavus isolates produced detectable levels of AFB1, and 71 isolates (87.6 %) possessed aflR gene in their AF synthesis gene cluster, while only 41 isolates (50.6 %) had the ver-1 gene present. Genetic diversity analysis using inter-simple sequence repeats (ISSR) markers revealed seven main clusters among the isolates and the genetic similarity coefficients of 81 A. flavus isolates ranged from 0.53 to 1.00. Additionally, coculture assays were conducted using two toxigenic and two atoxigenic isolates from the same grain depot to investigate the effect of intraspecific inhibition on AFB1 production and to assess the AFB1 contamination risk of storage rice. The in situ results demonstrated that the atoxigenic isolates effectively inhibited the AFB1 contamination of toxigenic isolates. These findings provide insight into the genetic diversity of A. flavus isolates populations and highlight the potential food safety hazards of them in stored rice grain in China.
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Affiliation(s)
- Song Tan
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, China; Collaborative Innovation Center for Modern Grain Circulation and Safety, Nanjing University of Finance and Economics, Nanjing 210023, China; Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Fang Ma
- Institute of Veterinary Immunology & Engineering, National Research Center of Engineering and Technology for Veterinary Biologicals, Jiangsu Key Laboratory for Food Quality and Safety-State Key Laboratory Cultivation Base, Ministry of Science and Technology, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
| | - Yajie Wu
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, China; Collaborative Innovation Center for Modern Grain Circulation and Safety, Nanjing University of Finance and Economics, Nanjing 210023, China; Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Yuancheng Xu
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, China; Collaborative Innovation Center for Modern Grain Circulation and Safety, Nanjing University of Finance and Economics, Nanjing 210023, China; Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Ajuan Niu
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, China; Collaborative Innovation Center for Modern Grain Circulation and Safety, Nanjing University of Finance and Economics, Nanjing 210023, China; Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Yuping Chen
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, China; Collaborative Innovation Center for Modern Grain Circulation and Safety, Nanjing University of Finance and Economics, Nanjing 210023, China; Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
| | - Guangyu Wang
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, China; Collaborative Innovation Center for Modern Grain Circulation and Safety, Nanjing University of Finance and Economics, Nanjing 210023, China; Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China.
| | - Weifen Qiu
- College of Food Science and Engineering, Nanjing University of Finance and Economics, Nanjing 210023, China; Collaborative Innovation Center for Modern Grain Circulation and Safety, Nanjing University of Finance and Economics, Nanjing 210023, China; Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China
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Krska R, Leslie JF, Haughey S, Dean M, Bless Y, McNerney O, Spence M, Elliott C. Effective approaches for early identification and proactive mitigation of aflatoxins in peanuts: An EU-China perspective. Compr Rev Food Sci Food Saf 2022; 21:3227-3243. [PMID: 35638328 DOI: 10.1111/1541-4337.12973] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 03/31/2022] [Accepted: 04/11/2022] [Indexed: 11/29/2022]
Abstract
Nearly 700,000 tonnes of peanuts are consumed annually in Europe. In the last 5 years, peanuts imported from China exceeded legal European Union (EU) aflatoxin limits more than 180 times. To prevent and mitigate aflatoxin contamination, the stages of the peanut chain most vulnerable to contamination must be assessed to determine how to interrupt the movement of contaminated produce. This paper discusses effective approaches for early identification and proactive mitigation of aflatoxins in peanuts to reduce a contaminant that is an impediment to trade. We consider (i) the results of the EU Commission's Directorate-General (DG) for Health and Food Safety review, (ii) the Code of Practice for the prevention and reduction of aflatoxins in peanuts issued by Food and Agriculture Organization/World Health Organization, (iii) the results from previous EU-China efforts, and (iv) the latest state-of-the-art technology in pre- and postharvest methods as essential elements of a sustainable program for integrated disease and aflatoxin management. These include preharvest use of biocontrol, biofertilizers, improved tillage, forecasting, and risk monitoring based on analysis of big data obtained by remote sensing. At the postharvest level, we consider rapid testing methods along the supply chain, Decision Support Systems for effective silo management, and effective risk monitoring during drying, storage, and transport. Available guidance and current recommendations are provided for successful practical implementation. Food safety standards also influence stakeholder and consumer trust and confidence, so we also consider the results of multiactor stakeholder group discussions.
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Affiliation(s)
- Rudolf Krska
- Vienna (BOKU), Institute of Bioanalytics and Agro-Metabolomics, Department of Agrobiotechnology IFA-Tulln, University of Natural Resources and Life Sciences, Tulln, Austria.,Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, UK
| | - John F Leslie
- Department of Plant Pathology, Throckmorton Plant Sciences Center, Kansas State University, Manhattan, Kansas, USA
| | - Simon Haughey
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, UK
| | - Moira Dean
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, UK
| | - Yoneal Bless
- Vienna (BOKU), Institute of Bioanalytics and Agro-Metabolomics, Department of Agrobiotechnology IFA-Tulln, University of Natural Resources and Life Sciences, Tulln, Austria
| | - Oonagh McNerney
- IRIS Technology Solutions S.L., Cornellà de Llobregat, Spain
| | - Michelle Spence
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, UK
| | - Chris Elliott
- Institute for Global Food Security, School of Biological Sciences, Queen's University Belfast, Belfast, UK
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Mamo FT, Shang B, Selvaraj JN, Zheng Y, Liu Y. Biocontrol efficacy of atoxigenic Aspergillus flavus strains against aflatoxin contamination in peanut field in Guangdong province, South China. Mycology 2022; 13:143-152. [PMID: 35711325 PMCID: PMC9196723 DOI: 10.1080/21501203.2021.1978573] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
Application of atoxigenic strains of Aspergillus flavusto soils is the most successful aflatoxin biological control approach. The objective of this study was to evaluate the efficacies of native non-aflatoxin producing (atoxigenic) strains as a biocontrol agent in peanut field in China. The competitive atoxigenic A. flavus strains (JS4, SI1and SXN) isolated from different crops, in China were used for field evaluation. The strains applied during the growing season (June – October, 2016) in the field at rate of 25 kg inoculum/hectare. The colonization of these biocontrol agents has been investigated and the population of A. flavus communities in soil were determined. The incidences of toxin producing (toxigenic) A. flavus strains and aflatoxin contamination in peanuts were also determined. Treated plots produced significant reductions in the incidence of toxigenic isolates of A. flavus in soil. However, the total fungal densities were not significantly different (p > 0.05) after treatments. Large percentage of aflatoxin reductions, ranging from 82.8% (SXN) up to 87.2% (JS4) were recorded in treated plots. Generally, the results suggest that the strategy can be used to control aflatoxin contamination and continuous evaluation should be done.
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Affiliation(s)
- Firew Tafesse Mamo
- School of Food Science and Engineering, Foshan University/South China Food Safety Research Center, Foshan, Guangdong, P R. China
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
- Ethiopian Biotechnology Institute, Addis Ababa, Ethiopia
| | - Bo Shang
- School of Food Science and Engineering, Foshan University/South China Food Safety Research Center, Foshan, Guangdong, P R. China
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| | | | - Yongquan Zheng
- State Key Laboratory for Biology Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
| | - Yang Liu
- School of Food Science and Engineering, Foshan University/South China Food Safety Research Center, Foshan, Guangdong, P R. China
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs, Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, P. R. China
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Mamo FT, Abate BA, Zheng Y, Nie C, He M, Liu Y. Distribution of Aspergillus Fungi and Recent Aflatoxin Reports, Health Risks, and Advances in Developments of Biological Mitigation Strategies in China. Toxins (Basel) 2021; 13:678. [PMID: 34678973 PMCID: PMC8541519 DOI: 10.3390/toxins13100678] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 09/15/2021] [Accepted: 09/20/2021] [Indexed: 12/24/2022] Open
Abstract
Aflatoxins (AFs) are secondary metabolites that represent serious threats to human and animal health. They are mainly produced by strains of the saprophytic fungus Aspergillus flavus, which are abundantly distributed across agricultural commodities. AF contamination is receiving increasing attention by researchers, food producers, and policy makers in China, and several interesting review papers have been published, that mainly focused on occurrences of AFs in agricultural commodities in China. The goal of this review is to provide a wider scale and up-to-date overview of AF occurrences in different agricultural products and of the distribution of A. flavus across different food and feed categories and in Chinese traditional herbal medicines in China, for the period 2000-2020. We also highlight the health impacts of chronic dietary AF exposure, the recent advances in biological AF mitigation strategies in China, and recent Chinese AF standards.
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Affiliation(s)
- Firew Tafesse Mamo
- School of Food Science and Engineering, Food Safety Research Centre, Foshan University, Foshan 528231, China; (C.N.); (M.H.)
- Ethiopian Biotechnology Institute, Addis Ababa 5954, Ethiopia;
| | | | - Yougquan Zheng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China;
| | - Chengrong Nie
- School of Food Science and Engineering, Food Safety Research Centre, Foshan University, Foshan 528231, China; (C.N.); (M.H.)
| | - Mingjun He
- School of Food Science and Engineering, Food Safety Research Centre, Foshan University, Foshan 528231, China; (C.N.); (M.H.)
| | - Yang Liu
- School of Food Science and Engineering, Food Safety Research Centre, Foshan University, Foshan 528231, China; (C.N.); (M.H.)
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Xu J, Wang P, Zhou Z, Cotty PJ, Kong Q. Selection of Atoxigenic Aspergillus flavus for Potential Use in Aflatoxin Prevention in Shandong Province, China. J Fungi (Basel) 2021; 7:jof7090773. [PMID: 34575811 PMCID: PMC8472152 DOI: 10.3390/jof7090773] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/13/2021] [Accepted: 09/13/2021] [Indexed: 11/17/2022] Open
Abstract
Aspergillus flavus is a common filamentous fungus widely present in the soil, air, and in crops. This facultative pathogen of both animals and plants produces aflatoxins, a group of mycotoxins with strong teratogenic and carcinogenic properties. Peanuts are highly susceptible to aflatoxin contamination and consumption of contaminated peanuts poses serious threats to the health of humans and domestic animals. Currently, the competitive displacement of aflatoxin-producers from agricultural environments by atoxigenic A. flavus is the most effective method of preventing crop aflatoxin contamination. In the current study, 47 isolates of A. flavus collected from peanut samples originating in Shandong Province were characterized with molecular methods and for aflatoxin-producing ability in laboratory studies. Isolates PA04 and PA10 were found to be atoxigenic members of the L strains morphotype. When co-inoculated with A. flavus NRRL3357 at ratios of 1:10, 1:1, and 10:1 (PA04/PA10: NRRL3357), both atoxigenic strains were able to reduce aflatoxin B1 (AFB1) levels, on both culture media and peanut kernels, by up to 90%. The extent to which atoxigenic strains reduced contamination was correlated with the inoculation ratio. Abilities to compete of PA04 and PA10 were also independently verified against local aflatoxin-producer PA37. The results suggest that the two identified atoxigenic strains are good candidates for active ingredients of biocontrol products for the prevention of aflatoxin contamination of peanuts in Shandong Province.
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Affiliation(s)
- Jia Xu
- School of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; (J.X.); (P.W.); (P.J.C.)
| | - Peng Wang
- School of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; (J.X.); (P.W.); (P.J.C.)
| | - Zehua Zhou
- Food Technology Department, Wageningen University & Research, 6700 AK Wageningen, The Netherlands;
| | - Peter John Cotty
- School of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; (J.X.); (P.W.); (P.J.C.)
| | - Qing Kong
- School of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; (J.X.); (P.W.); (P.J.C.)
- Correspondence: ; Tel.: +86-532-8203-2290; Fax: +86-532-8203-238
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Zhang Y, Zhou M, Cheng H, Luo S, Sun Q. Insight into the substrate-dependent anti-aflatoxigenic effects of nanosized ZnO film: Electron transfer directed oxidative stress mechanisms. Colloids Surf B Biointerfaces 2021; 207:111997. [PMID: 34311197 DOI: 10.1016/j.colsurfb.2021.111997] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 07/14/2021] [Accepted: 07/19/2021] [Indexed: 11/19/2022]
Abstract
Exploring new anti-aflatoxigenic materials and their mechanisms are critical to reduce the prevalence of drug-resistant fungi and the contamination of aflatoxins. Zinc oxide nanoparticles (ZnONPs) are promising antifungal candidates but supporting substrates generally affect their antifungal activities. In this study, ZnONPs with a three-dimensional flower-like hierarchical microstructure bound to different substrates as anti-aflatoxigenic composites were prepared using a facile deposition method. It was found that ZnO nanocomposites showed the substrate-dependent anti-aflatoxigenic activities. The antifungal activities of ZnO films toward A. flavus growth and aflatoxin B1 production decreased significantly in the order ZnO@Zn>ZnO@Sn>ZnO@Steel>ZnO@Glass. The electrical conductivity of the substrate should play an important role for antifungal response. When compared with ZnO@Sn and ZnO@Steel, the conductivity value of ZnO@Zn was 2.07-fold and 14.84-fold of them, respectively. The higher the electrical conductivity of the substrate, the better the anti-aflatoxigenic efficiency of the composite. Such anti-aflatoxigenic activity was also due to ROS generation through electron transfer between fungi and the ZnO-substrate system, which could provoke the strength of intracellular oxidative stress. This mechanism was further confirmed using several assays such as hyphal morphology analysis, Zn2+ release, ROS evaluation, lipid peroxidation and antioxidant response. Collectively, improvement in knowledge regarding anti-aflatoxigenic performance of ZnONPs can help develop novel and effective strategies to reduce fungi growth and aflatoxin contamination in the food field.
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Affiliation(s)
- Yichuan Zhang
- Department of Environmental Art and Design, Chongqing College of Electronic Engineering, Shapingba District, Chongqing, 401331, People's Republic of China
| | - Miya Zhou
- College of Life Sciences, Chongqing Normal University, No. 37 Chengzhong Road, Shapingba District, Chongqing, 401331, People's Republic of China
| | - Huanmei Cheng
- College of Life Sciences, Chongqing Normal University, No. 37 Chengzhong Road, Shapingba District, Chongqing, 401331, People's Republic of China
| | - Songyi Luo
- Department of Environmental Art and Design, Chongqing College of Electronic Engineering, Shapingba District, Chongqing, 401331, People's Republic of China
| | - Qi Sun
- College of Life Sciences, Chongqing Normal University, No. 37 Chengzhong Road, Shapingba District, Chongqing, 401331, People's Republic of China.
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Chang PK, Chang TD, Katoh K. Deciphering the origin of Aspergillus flavus NRRL21882, the active biocontrol agent of Afla-Guard ®. Lett Appl Microbiol 2021; 72:509-516. [PMID: 33251654 DOI: 10.1111/lam.13433] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/19/2020] [Accepted: 11/19/2020] [Indexed: 11/28/2022]
Abstract
Single nucleotide polymorphisms (SNPs) of genome sequences of eight Aspergillus flavus and seven Aspergillus oryzae strains were extracted with Mauve, a multiple-genome alignment programme. A phylogenetic analysis with sequences comprised of concatenated total SNPs by the unweighted pair group method with arithmetic mean (UPGMA) of MAFFT adequately separated them into three groups, A. flavus S-morphotype, A. flavus L-morphotype and A. oryzae. Divergence time inferred for A. flavus NRRL21882, the active agent of the biocontrol product Afla-Guard® , and S-morphotype was about 5·1 mya. Another biocontrol strain, A. flavus AF36, diverged from aflatoxigenic L-morphotype about 2·6-3·0 mya. Despite the close relatedness of A. oryzae to A. flavus, A. oryzae strains likely evolved from aflatoxigenic Aspergillus aflatoxiformans (=A. parvisclerotigenus). A survey of A. flavus populations implies that prior Afla-Guard® applications are associated with prevalence of NRRL21882-type isolates in Mississippi fields. In addition, a few NRRL21882 relatives were identified. A. flavus Og0222, a biocontrol ingredient of Aflasafe™, was verified as a NRRL21882-type strain, having identical sequence breakpoints that led to deletion of aflatoxin and cyclopiazonic acid gene clusters. A similar UPGMA analysis suggests that the occurrence of NRRL21882-type strains is a more recent event.
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Affiliation(s)
- P-K Chang
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, LA, USA
| | - T D Chang
- 400 Poydras Street, New Orleans, LA, USA
| | - K Katoh
- Immunology Frontier Research Center, Osaka University, Suita, Japan
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Intanon W, Vichiansan N, Leksakul K, Boonyawan D, Kumla J, Suwannarach N, Lumyong S. Inhibition of the aflatoxin‐producing fungus
Aspergillus flavus
by a plasma jet system. J FOOD PROCESS PRES 2020. [DOI: 10.1111/jfpp.15045] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Winai Intanon
- Department of Industrial Engineering, Faculty of Engineering Chiang Mai University Chiang Mai Thailand
| | - Norrapon Vichiansan
- Department of Industrial Engineering, Faculty of Engineering Chiang Mai University Chiang Mai Thailand
| | - Komgrit Leksakul
- Department of Industrial Engineering, Faculty of Engineering Chiang Mai University Chiang Mai Thailand
| | - Dheerawan Boonyawan
- Department of Physics and Materials Science, Faculty of Science Chiang Mai University Chiang Mai Thailand
| | - Jaturong Kumla
- Department of Biology, Faculty of Science Chiang Mai University Chiang Mai Thailand
- Center of Excellence in Microbial Diversity and Sustainable Utilization Chiang Mai University Chiang Mai Thailand
| | - Nakarin Suwannarach
- Department of Biology, Faculty of Science Chiang Mai University Chiang Mai Thailand
- Center of Excellence in Microbial Diversity and Sustainable Utilization Chiang Mai University Chiang Mai Thailand
| | - Saisamorn Lumyong
- Department of Biology, Faculty of Science Chiang Mai University Chiang Mai Thailand
- Center of Excellence in Microbial Diversity and Sustainable Utilization Chiang Mai University Chiang Mai Thailand
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Agbetiameh D, Ortega-Beltran A, Awuah RT, Atehnkeng J, Elzein A, Cotty PJ, Bandyopadhyay R. Field efficacy of two atoxigenic biocontrol products for mitigation of aflatoxin contamination in maize and groundnut in Ghana. BIOLOGICAL CONTROL : THEORY AND APPLICATIONS IN PEST MANAGEMENT 2020; 150:104351. [PMID: 33144821 PMCID: PMC7457722 DOI: 10.1016/j.biocontrol.2020.104351] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/13/2020] [Accepted: 06/15/2020] [Indexed: 06/11/2023]
Abstract
Biological control is one of the recommended methods for aflatoxin mitigation. Biocontrol products must be developed, and their efficacy demonstrated before widespread use. Efficacy of two aflatoxin biocontrol products, Aflasafe GH01 and Aflasafe GH02, were evaluated in 800 maize and groundnut farmers' fields during 2015 and 2016 in the Ashanti, Brong Ahafo, Northern, Upper East, and Upper West regions of Ghana. Both products were developed after an extensive examination of fungi associated with maize and groundnut in Ghana. Each product contains as active ingredient fungi four Aspergillus flavus isolates belonging to atoxigenic African Aspergillus Vegetative Compatibility Groups (AAVs) widely distributed across Ghana. An untreated field was maintained for each treated field to determine product efficacy. Proportions of atoxigenic AAVs composing each product were assessed in soils before product application, and soils and grains at harvest. Significant (P < 0.05) displacement of toxigenic fungi occurred in both crops during both years, in all five regions. Biocontrol-treated crops consistently had significantly (P < 0.05) less aflatoxins (range = 76% to 100% less; average = 99% less) than untreated crops. Results indicate that both biocontrol products are highly efficient, cost-effective, environmentally safe tools for aflatoxin mitigation. Most crops from treated fields could have been sold in both local and international food and feed premium markets. Adoption and use of biocontrol products have the potential to improve the health of Ghanaians, and both income and trade opportunities of farmers, aggregators, distributors, and traders.
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Affiliation(s)
- Daniel Agbetiameh
- International Institute of Tropical Agriculture (IITA), Ibadan 200001, Nigeria
- Department of Crop and Soil Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Richard T. Awuah
- Department of Crop and Soil Sciences, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Joseph Atehnkeng
- International Institute of Tropical Agriculture (IITA), Ibadan 200001, Nigeria
| | - Abuelgasim Elzein
- International Institute of Tropical Agriculture (IITA), Ibadan 200001, Nigeria
| | - Peter J. Cotty
- United States Department of Agriculture – Agricultural Research Service, Tucson, AZ 85721, USA
- School of Food Science and Engineering, Ocean University of China, Qingdao, China
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Raksha Rao K, Vipin AV, Venkateswaran G. Mechanism of inhibition of aflatoxin synthesis by non-aflatoxigenic strains of Aspergillus flavus. Microb Pathog 2020; 147:104280. [PMID: 32505654 DOI: 10.1016/j.micpath.2020.104280] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 05/02/2020] [Accepted: 05/04/2020] [Indexed: 02/04/2023]
Abstract
Aflatoxins are toxic secondary metabolites primarily produced by Aspergillus flavus and A. paraciticus. Exposure to these mycotoxins through contaminated food and feed may cause oxidative stress and liver toxicity in animals. One of the promising strategies to mitigate aflatoxin accumulation is the biological management during pre-harvest using non-aflatoxigenic A. flavus. The mechanism offered by these strains in mitigating aflatoxin is still unclear. Thus, the aim of the present study is to delineate the mechanism of intraspecific inhibition of aflatoxin production. Among the 18 non-aflatoxigenic strains evaluated, six strains were able to reduce more than 50% of the aflatoxins produced by the native aflatoxigenic strains. The non-aflatoxigenic strains used in this study failed to degrade the aflatoxins. Eventhough, the non-aflatoxigenic strains were not able to inhibit the synthesis of aflatoxins completely. Four non-aflatoxigenic isolates could competitively excluded the aflatoxigenic strain. Furthermore, when non-aflatoxigenic and an aflatoxigenic isolate were separated by 0.4 and 3 μm filters, aflatoxin synthesis was not significantly reduced. However, when the pore size was 8 μm, there was a significant decrease in aflatoxin production. This results suggest the role of physical contact between the hyphae, thigmoregulation, in the inhibition of aflatoxin production. Additionally, to better understand the transcriptional level control of this phenomenon, we analyzed the gene expression profile of aflatoxin biosynthesis genes in the aflatoxigenic strain. The aflatoxin biosynthesis genes were down regulated in the aflatoxigenic strain in contact with non-aflatoxigenic strain group when compared to the control. This is the first evidence of the combined action of competitive exclusion and thigmodownregulation which led to the intraspecific inhibition of aflatoxin production.
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Affiliation(s)
- K Raksha Rao
- Microbiology and Fermentation Technology, CSIR-Central Food Technological Research Institute, Mysore, 570 020, Karnataka, India; Academy of Scientific & Innovative Research (AcSIR), CSIR-Central Food Technological Research Institute Campus, Mysore, 570 020, Karnataka, India
| | - A V Vipin
- Microbiology and Fermentation Technology, CSIR-Central Food Technological Research Institute, Mysore, 570 020, Karnataka, India; Academy of Scientific & Innovative Research (AcSIR), CSIR-Central Food Technological Research Institute Campus, Mysore, 570 020, Karnataka, India
| | - G Venkateswaran
- Microbiology and Fermentation Technology, CSIR-Central Food Technological Research Institute, Mysore, 570 020, Karnataka, India; Academy of Scientific & Innovative Research (AcSIR), CSIR-Central Food Technological Research Institute Campus, Mysore, 570 020, Karnataka, India.
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12
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Rao KR, Vipin AV, Venkateswaran G. Molecular profile of non-aflatoxigenic phenotype in native strains of Aspergillus flavus. Arch Microbiol 2020; 202:1143-1155. [PMID: 32062689 DOI: 10.1007/s00203-020-01822-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/13/2020] [Accepted: 01/28/2020] [Indexed: 11/26/2022]
Abstract
Aflatoxins are the most common mycotoxin contaminant reported in food and feed. Aflatoxin B1, the most toxic among different aflatoxins, is known to cause hepatocellular carcinoma in animals. Aspergillus flavus and A. parasiticus are the main producers of aflatoxins and are widely distributed in tropical countries. Even though several robust strategies have been in use to control aflatoxin contamination, the control at the pre-harvest level is primitive and incompetent. Therefore, the aim of the study was to isolate and identify the non-aflatoxigenic A. flavus and to delineate the molecular mechanism for the loss of aflatoxin production by the non-aflatoxigenic isolates. Eighteen non-aflatoxigenic strains were isolated from various biological sources using cultural and analytical methods. Among the 18 isolates, 8 isolates produced sclerotia and 17 isolates had type I deletion in norB-cypA region. The isolates were confirmed as A. flavus using gene-specific PCR and sequencing of the ITS region. Later, aflatoxin gene-specific PCR revealed that the defect in one or more genes has led to non-aflatoxigenic phenotype. The strain R9 had maximum defect, and genes avnA and verB had the highest frequency of defect among the non-aflatoxigenic strains. Further, qRT-PCR confirmed that the non-aflatoxigenic strains had high frequency of defect or downregulation in the late pathway genes compared to early pathway genes. Thus, these non-aflatoxigenic strains can be the potential candidates for an effective and proficient strategy for the control of pre-harvest aflatoxin contamination.
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Affiliation(s)
- K Raksha Rao
- Microbiology and Fermentation Technology, CSIR-Central Food Technological Research Institute, Mysuru, Karnataka, 570 020, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Central Food Technological Research Institute Campus, Mysuru, Karnataka, 570 020, India
| | - A V Vipin
- Microbiology and Fermentation Technology, CSIR-Central Food Technological Research Institute, Mysuru, Karnataka, 570 020, India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Central Food Technological Research Institute Campus, Mysuru, Karnataka, 570 020, India
| | - G Venkateswaran
- Microbiology and Fermentation Technology, CSIR-Central Food Technological Research Institute, Mysuru, Karnataka, 570 020, India.
- Academy of Scientific and Innovative Research (AcSIR), CSIR-Central Food Technological Research Institute Campus, Mysuru, Karnataka, 570 020, India.
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13
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Ren Y, Jin J, Zheng M, Yang Q, Xing F. Ethanol Inhibits Aflatoxin B 1 Biosynthesis in Aspergillus flavus by Up-Regulating Oxidative Stress-Related Genes. Front Microbiol 2020; 10:2946. [PMID: 32010073 PMCID: PMC6978751 DOI: 10.3389/fmicb.2019.02946] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 12/06/2019] [Indexed: 01/04/2023] Open
Abstract
As the most carcinogenic, toxic, and economically costly mycotoxins, aflatoxin B1 (AFB1) is primarily biosynthesized by Aspergillus flavus and Aspergillus parasiticus. Aflatoxin biosynthesis is related to oxidative stress and functions as a second line of defense from excessive reactive oxygen species. Here, we find that ethanol can inhibit fungal growth and AFB1 production by A. flavus in a dose-dependent manner. Then, the ethanol’s molecular mechanism of action on AFB1 biosynthesis was revealed using a comparative transcriptomic analysis. RNA-Seq data indicated that all the genes except for aflC in the aflatoxin gene cluster were down-regulated by 3.5% ethanol. The drastic repression of aflatoxin structural genes including the complete inhibition of aflK and aflLa may be correlated with the down-regulation of the transcription regulator genes aflR and aflS in the cluster. This may be due to the repression of several global regulator genes and the subsequent overexpression of some oxidative stress-related genes. The suppression of several key aflatoxin genes including aflR, aflD, aflM, and aflP may also be associated with the decreased expression of the global regulator gene veA. In particular, ethanol exposure caused the decreased expression of stress response transcription factor srrA and the overexpression of bZIP transcription factor ap-1, C2H2 transcription factors msnA and mtfA, together with the enhanced levels of anti-oxidant enzymatic genes including Cat, Cat1, Cat2, CatA, and Cu, Zn superoxide dismutase gene sod1. Taken together, these RNA-Seq data strongly suggest that ethanol inhibits AFB1 biosynthesis by A. flavus via enhancing fungal oxidative stress response. In conclusion, this study served to reveal the anti-aflatoxigenic mechanisms of ethanol in A. flavus and to provide solid evidence for its use in controlling AFB1 contamination.
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Affiliation(s)
- Yaoyao Ren
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Jing Jin
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs/Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Mumin Zheng
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Qingli Yang
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Fuguo Xing
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, China.,Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs/Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
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14
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Guan X, Zhao Y, Liu X, Shang B, Xing F, Zhou L, Wang Y, Zhang C, Bhatnagar D, Liu Y. The bZIP transcription factor Afap1 mediates the oxidative stress response and aflatoxin biosynthesis in Aspergillus flavus. Rev Argent Microbiol 2019; 51:292-301. [DOI: 10.1016/j.ram.2018.07.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 06/26/2018] [Accepted: 07/15/2018] [Indexed: 11/28/2022] Open
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15
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Mitema A, Okoth S, Rafudeen SM. The Development of a qPCR Assay to Measure Aspergillus flavus Biomass in Maize and the Use of a Biocontrol Strategy to Limit Aflatoxin Production. Toxins (Basel) 2019; 11:toxins11030179. [PMID: 30934573 PMCID: PMC6468655 DOI: 10.3390/toxins11030179] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2019] [Revised: 03/14/2019] [Accepted: 03/18/2019] [Indexed: 01/10/2023] Open
Abstract
Aspergillus flavus colonisation of maize can produce mycotoxins that are detrimental to both human and animal health. Screening of maize lines, resistant to A. flavus infection, together with a biocontrol strategy, could help minimize subsequent aflatoxin contamination. We developed a qPCR assay to measure A. flavus biomass and showed that two African maize lines, GAF4 and KDV1, had different fungal loads for the aflatoxigenic isolate (KSM014), fourteen days after infection. The qPCR assay revealed no significant variation in A. flavus biomass between diseased and non-diseased maize tissues for GAF4, while KDV1 had a significantly higher A. flavus biomass (p < 0.05) in infected shoots and roots compared to the control. The biocontrol strategy using an atoxigenic isolate (KSM012) against the toxigenic isolate (KSM014), showed aflatoxin production inhibition at the co-infection ratio, 50:50 for both maize lines (KDV1 > 99.7% and GAF ≥ 69.4%), as confirmed by bioanalytical techniques. As far as we are aware, this is the first report in Kenya where the biomass of A. flavus from maize tissue was detected and quantified using a qPCR assay. Our results suggest that maize lines, which have adequate resistance to A. flavus, together with the appropriate biocontrol strategy, could limit outbreaks of aflatoxicoses.
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Affiliation(s)
- Alfred Mitema
- Plant Stress Laboratory 204/207, Department of Molecular and Cell Biology, MCB Building, Upper Campus, University of Cape Town, Private bag X3, Rondebosch, Cape Town 7701, South Africa.
- Department of Botany, School of Biological Sciences, University of Nairobi, P.O. Box 30197, Nairobi 00100, Kenya.
| | - Sheila Okoth
- Department of Botany, School of Biological Sciences, University of Nairobi, P.O. Box 30197, Nairobi 00100, Kenya.
| | - Suhail M Rafudeen
- Plant Stress Laboratory 204/207, Department of Molecular and Cell Biology, MCB Building, Upper Campus, University of Cape Town, Private bag X3, Rondebosch, Cape Town 7701, South Africa.
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16
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Ren Y, Jin J, Zheng M, Yang Q, Xing F. Ethanol Inhibits Aflatoxin B 1 Biosynthesis in Aspergillus flavus by Up-Regulating Oxidative Stress-Related Genes. Front Microbiol 2019. [PMID: 32010073 DOI: 10.3389/fmicb.2019.02946/bibtex] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/31/2023] Open
Abstract
As the most carcinogenic, toxic, and economically costly mycotoxins, aflatoxin B1 (AFB1) is primarily biosynthesized by Aspergillus flavus and Aspergillus parasiticus. Aflatoxin biosynthesis is related to oxidative stress and functions as a second line of defense from excessive reactive oxygen species. Here, we find that ethanol can inhibit fungal growth and AFB1 production by A. flavus in a dose-dependent manner. Then, the ethanol's molecular mechanism of action on AFB1 biosynthesis was revealed using a comparative transcriptomic analysis. RNA-Seq data indicated that all the genes except for aflC in the aflatoxin gene cluster were down-regulated by 3.5% ethanol. The drastic repression of aflatoxin structural genes including the complete inhibition of aflK and aflLa may be correlated with the down-regulation of the transcription regulator genes aflR and aflS in the cluster. This may be due to the repression of several global regulator genes and the subsequent overexpression of some oxidative stress-related genes. The suppression of several key aflatoxin genes including aflR, aflD, aflM, and aflP may also be associated with the decreased expression of the global regulator gene veA. In particular, ethanol exposure caused the decreased expression of stress response transcription factor srrA and the overexpression of bZIP transcription factor ap-1, C2H2 transcription factors msnA and mtfA, together with the enhanced levels of anti-oxidant enzymatic genes including Cat, Cat1, Cat2, CatA, and Cu, Zn superoxide dismutase gene sod1. Taken together, these RNA-Seq data strongly suggest that ethanol inhibits AFB1 biosynthesis by A. flavus via enhancing fungal oxidative stress response. In conclusion, this study served to reveal the anti-aflatoxigenic mechanisms of ethanol in A. flavus and to provide solid evidence for its use in controlling AFB1 contamination.
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Affiliation(s)
- Yaoyao Ren
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Jing Jin
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs/Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Mumin Zheng
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Qingli Yang
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, China
| | - Fuguo Xing
- College of Food Science and Engineering, Qingdao Agricultural University, Qingdao, China
- Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture and Rural Affairs/Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, China
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17
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Lv C, Wang P, Ma L, Zheng M, Liu Y, Xing F. Large-Scale Comparative Analysis of Eugenol-Induced/Repressed Genes Expression in Aspergillus flavus Using RNA-seq. Front Microbiol 2018; 9:1116. [PMID: 29899734 PMCID: PMC5988903 DOI: 10.3389/fmicb.2018.01116] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 05/11/2018] [Indexed: 11/24/2022] Open
Abstract
Aflatoxin B1 (AFB1), which is mainly produced by Aspergillus flavus and Aspergillus parasiticus, is the most toxic and hepatocarcinogenic polyketide known. Chemical fungicides are currently utilized to reduce this fungal contaminant, but they are potentially harmful to human health and the environment. Therefore, natural anti-aflatoxigenic products are used as sustainable alternatives to control food and feed contamination. For example, eugenol, presents in many essential oils, has been identified as an aflatoxin inhibitor. However, its exact mechanism of inhibition is yet to be clarified. In this study, the anti-aflatoxigenic mechanism of eugenol in A. flavus was determined using a comparative transcriptomic approach. Twenty of twenty-nine genes in the aflatoxin biosynthetic pathway were down-regulated by eugenol. The most strongly down-regulated gene was aflMa, followed by aflI, aflJ, aflCa, aflH, aflNa, aflE, aflG, aflM, aflD, and aflP. However, the expression of the regulator gene aflR did not change significantly and the expression of aflS was slightly up-regulated. The down-regulation of the global regulator gene veA resulted in the up-regulation of srrA, and the down-regulation of ap-1 and mtfA. The early developmental regulator brlA was profoundly up-regulated in A. flavus after eugenol treatment. These results suggested a model in which eugenol improves fungal development by up-regulating the expression of brlA by the suppression of veA expression and inhibits aflatoxin production through the suppression of veA expression. Exposure to eugenol also caused dysregulated transcript levels of the G protein-coupled receptors (GPCRs) and oxylipins genes. A Gene Ontology analysis indicated that the genes that were highly responsive to eugenol were mainly enriched in RNA-binding functions, suggesting that post-transcriptional modification plays a pivotal role in aflatoxin biosynthesis. KEGG analysis showed that ribosome biogenesis was the most dysregulated pathway, suggesting that eugenol dysregulates ribosome biogenesis, which then interrupts the biosynthesis of Nor-1, Ver-1, and OmtA, and prevents aflatoxisomes performing their normal function in aflatoxin production. In conclusion, our results indicated that eugenol inhibited AFB1 production by modulating the expression of structural genes in aflatoxin pathway, fungal antioxidant status, post-transcriptional modifications and biosynthesis of backbone enzymes in A. flavus.
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Affiliation(s)
- Cong Lv
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture, Beijing, China
| | - Ping Wang
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture, Beijing, China
| | - Longxue Ma
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture, Beijing, China
| | - Mumin Zheng
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture, Beijing, China
| | - Yang Liu
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture, Beijing, China
| | - Fuguo Xing
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences/Key Laboratory of Agro-products Quality and Safety Control in Storage and Transport Process, Ministry of Agriculture, Beijing, China
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18
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Agbetiameh D, Ortega-Beltran A, Awuah RT, Atehnkeng J, Cotty PJ, Bandyopadhyay R. Prevalence of Aflatoxin Contamination in Maize and Groundnut in Ghana: Population Structure, Distribution, and Toxigenicity of the Causal Agents. PLANT DISEASE 2018; 102:764-772. [PMID: 30673407 PMCID: PMC7779968 DOI: 10.1094/pdis-05-17-0749-re] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Aflatoxin contamination in maize and groundnut is perennial in Ghana with substantial health and economic burden on the population. The present study examined for the first time the prevalence of aflatoxin contamination in maize and groundnut in major producing regions across three agroecological zones (AEZs) in Ghana. Furthermore, the distribution and aflatoxin-producing potential of Aspergillus species associated with both crops were studied. Out of 509 samples (326 of maize and 183 of groundnut), 35% had detectable levels of aflatoxins. Over 15% of maize and 11% of groundnut samples exceeded the aflatoxin threshold limits set by the Ghana Standards Authority of 15 and 20 ppb, respectively. Mycoflora analyses revealed various species and morphotypes within the Aspergillus section Flavi. A total of 5,083 isolates were recovered from both crops. The L morphotype of Aspergillus flavus dominated communities with 93.3% of the population, followed by Aspergillus spp. with S morphotype (6%), A. tamarii (0.4%), and A. parasiticus (0.3%). Within the L morphotype, the proportion of toxigenic members was significantly (P < 0.05) higher than that of atoxigenic members across AEZs. Observed and potential aflatoxin concentrations indicate that on-field aflatoxin management strategies need to be implemented throughout Ghana. The recovered atoxigenic L morphotype fungi are genetic resources that can be employed as biocontrol agents to limit aflatoxin contamination of maize and groundnut in Ghana. Copyright © 2018 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .
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Affiliation(s)
- D Agbetiameh
- International Institute of Tropical Agriculture (IITA), PMB 5320, Ibadan, Nigeria, and Department of Crop and Soil Sciences, Kwame Nkrumah University of Science and Technology (KNUST), Kumasi, Ghana
| | | | - R T Awuah
- Department of Crop and Soil Sciences, KNUST, Kumasi, Ghana
| | - J Atehnkeng
- IITA, Chitedze Research Station, P.O. Box 30258, Lilongwe 3, Malawi
| | - P J Cotty
- United States Department of Agriculture, Agricultural Research Service, School of Plant Sciences, University of Arizona, Tucson, AZ 85721
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Extrinsic harmful residues in Chinese herbal medicines: types, detection, and safety evaluation. CHINESE HERBAL MEDICINES 2018. [DOI: 10.1016/j.chmed.2018.02.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
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20
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Zhang SY, Wang H, Yang M, Yao DS, Xie CF, Liu DL. Versicolorin A is a potential indicator of aflatoxin contamination in the granary-stored corn. Food Addit Contam Part A Chem Anal Control Expo Risk Assess 2018; 35:972-984. [PMID: 29337658 DOI: 10.1080/19440049.2017.1419579] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The objective of this study was to evaluate the feasibility of the predictive monitoring of aflatoxin B1 (AFB1) under granary conditions, since mycotoxin contamination of the stored grain represents an important issue. Using the storage test, we investigated the relationship between versicolorin A (Ver A, an intermediate in AFB1 biosynthesis) levels and the levels of aflatoxigenic fungi, and their relationship with aflatoxin production. All samples, except for one, were found to be contaminated with aflatoxigenic fungi using PCR analyses, while their AFB1 levels were not detectable before the storage test using an enzyme-linked immunosorbent assay (ELISA) method with an LOD of 2 μg/kg. Aflatoxigenic fungi levels were analysed, as well as Ver A levels prior to the accumulation of AFB1 (Levels were ≥5 μg/kg; the permissible levels of AFB1 in corn intended for direct consumption are <5 μg/kg (EC)). Statistical analyses demonstrated that aflatoxin levels after both actual storage and safe storage (AFB1˂5μg/kg) times are significantly correlated with the Ver A levels and the changes in Ver A levels (ΔVer A). Both high and variable Ver A levels were indicative of the vigorous metabolic activity of aflatoxigenic fungi. In contrast, steady Ver A levels showed that aflatoxin production by the fungi was not active. Monitoring Ver A levels and their changes may allow an earlier detection of harmful aflatoxin contamination in the stored grain. Additionally, the toxicity of Ver A should be further examined. The results of our study indicate that the monitoring of Ver A levels, even when the AFB1 levels are very low, may increase the safety of grain consumption, especially considering Ver A toxicity.
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Affiliation(s)
- Shu-Yao Zhang
- a Department of Biotechnology, College of Life Science and Technology , Jinan University , Guangzhou , China.,b State Key Laboratory of Applied Microbiology Southern China, Guangdong Provincial Key Laboratory of Microbial Culture Collection and Application , Guangdong Institute of Microbiology , Guangzhou , China.,c Institute of Microbial Biotechnology , Jinan University , Guangzhou , China
| | - Hao Wang
- a Department of Biotechnology, College of Life Science and Technology , Jinan University , Guangzhou , China.,c Institute of Microbial Biotechnology , Jinan University , Guangzhou , China
| | - Min Yang
- a Department of Biotechnology, College of Life Science and Technology , Jinan University , Guangzhou , China.,c Institute of Microbial Biotechnology , Jinan University , Guangzhou , China
| | - Dong-Sheng Yao
- a Department of Biotechnology, College of Life Science and Technology , Jinan University , Guangzhou , China.,c Institute of Microbial Biotechnology , Jinan University , Guangzhou , China.,d National Engineering Research Centre of Genetic Medicine , Guangzhou , China
| | - Chun-Fang Xie
- a Department of Biotechnology, College of Life Science and Technology , Jinan University , Guangzhou , China.,c Institute of Microbial Biotechnology , Jinan University , Guangzhou , China.,d National Engineering Research Centre of Genetic Medicine , Guangzhou , China
| | - Da-Ling Liu
- a Department of Biotechnology, College of Life Science and Technology , Jinan University , Guangzhou , China.,c Institute of Microbial Biotechnology , Jinan University , Guangzhou , China
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21
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Mamo FT, Shang B, Selvaraj JN, Wang Y, Liu Y. Isolation and characterization of Aspergillus flavus strains in China. J Microbiol 2018; 56:119-127. [PMID: 29392555 DOI: 10.1007/s12275-018-7144-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 11/07/2017] [Accepted: 11/10/2017] [Indexed: 11/25/2022]
Abstract
Important staple foods (peanuts, maize and rice) are susceptible to contamination by aflatoxin (AF)-producing fungi such as Aspergillus flavus. The objective of this study was to explore non-aflatoxin-producing (atoxigenic) A. flavus strains as biocontrol agents for the control of AFs. In the current study, a total of 724 A. flavus strains were isolated from different regions of China. Polyphasic approaches were utilized for species identification. Non-aflatoxin and non-cyclopiazonic acid (CPA)-producing strains were further screened for aflatoxin B1 (AFB1) biosynthesis pathway gene clusters using a PCR assay. Strains lacking an amplicon for the regulatory gene aflR were then analyzed for the presence of the other 28 biosynthetic genes. Only 229 (32%) of the A. flavus strains were found to be atoxigenic. Smaller (S) sclerotial phenotypes were dominant (51%) compared to large (L, 34%) and non-sclerotial (NS, 15%) phenotypes. Among the atoxigenic strains, 24 strains were PCR-negative for the fas-1 and aflJ genes. Sixteen (67%) atoxigenic A. flavus strains were PCRnegative for 10 or more of the biosynthetic genes. Altogether, 18 new PCR product patterns were observed, indicating great diversity in the AFB1 biosynthesis pathway. The current study demonstrates that many atoxigenic A. flavus strains can be isolated from different regions of China. In the future laboratory as well as field based studies are recommended to test these atoxigenic strains as biocontrol agents for aflatoxin contamination.
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Affiliation(s)
- Firew Tafesse Mamo
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, P. R. China
- Key Laboratory of Agro-products Processing, Ministry of Agriculture, Beijing, 100193, P. R. China
| | - Bo Shang
- Academy of State Administration of Grain, Beijing, 100037, P. R. China
| | | | - Yan Wang
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, P. R. China
- Key Laboratory of Agro-products Processing, Ministry of Agriculture, Beijing, 100193, P. R. China
| | - Yang Liu
- Institute of Food Science and Technology, Chinese Academy of Agricultural Sciences, Beijing, 100193, P. R. China.
- Key Laboratory of Agro-products Processing, Ministry of Agriculture, Beijing, 100193, P. R. China.
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22
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Sun Q, Shang B, Wang L, Lu Z, Liu Y. Cinnamaldehyde inhibits fungal growth and aflatoxin B1 biosynthesis by modulating the oxidative stress response of Aspergillus flavus. Appl Microbiol Biotechnol 2015; 100:1355-1364. [DOI: 10.1007/s00253-015-7159-z] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 11/01/2015] [Accepted: 11/06/2015] [Indexed: 11/24/2022]
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Chang PK, Scharfenstein LL, Solorzano CD, Abbas HK, Hua SST, Jones WA, Zablotowicz RM. High sequence variations in the region containing genes encoding a cellular morphogenesis protein and the repressor of sexual development help to reveal origins of Aspergillus oryzae. Int J Food Microbiol 2015; 200:66-71. [PMID: 25689355 DOI: 10.1016/j.ijfoodmicro.2015.01.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 01/21/2015] [Accepted: 01/28/2015] [Indexed: 01/28/2023]
Abstract
Aspergillus oryzae and Aspergillus flavus are closely related fungal species. The A. flavus morphotype that produces numerous small sclerotia (S strain) and aflatoxin has a unique 1.5 kb deletion in the norB-cypA region of the aflatoxin gene cluster (i.e. the S genotype). Phylogenetic studies have indicated that an isolate of the nonaflatoxigenic A. flavus with the S genotype is the ancestor of A. oryzae. Genome sequence comparison between A. flavus NRRL3357, which produces large sclerotia (L strain), and S-strain A. flavus 70S identified a region (samA-rosA) that was highly variable in the two morphotypes. A third type of samA-rosA region was found in A. oryzae RIB40. The three samA-rosA types were later revealed to be commonly present in A. flavus L-strain populations. Of the 182 L-strain A. flavus field isolates examined, 46%, 15% and 39% had the samA-rosA type of NRRL3357, 70S and RIB40, respectively. The three types also were found in 18 S-strain A. flavus isolates with different proportions. For A. oryzae, however, the majority (80%) of the 16 strains examined had the RIB40 type and none had the NRRL3357 type. The results suggested that A. oryzae strains in the current culture collections were mostly derived from the samA-rosA/RIB40 lineage of the nonaflatoxigenic A. flavus with the S genotype.
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Affiliation(s)
- Perng-Kuang Chang
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, LA 70124, United States.
| | - Leslie L Scharfenstein
- Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, LA 70124, United States
| | - Cesar D Solorzano
- Biological Control of Pests Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Stoneville, MS 38776, United States
| | - Hamed K Abbas
- Biological Control of Pests Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Stoneville, MS 38776, United States
| | - Sui-Sheng T Hua
- Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Albany, CA, 94710, United States
| | - Walker A Jones
- Biological Control of Pests Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Stoneville, MS 38776, United States
| | - Robert M Zablotowicz
- Crop Production Systems Research Unit, Agricultural Research Service, U.S. Department of Agriculture, Stoneville, MS 38776, United States
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Kim MS, Kim S, Ha BS, Park HY, BaeK SY, Yeo SH, Ro HS. Diversity, Saccharification Capacity, and Toxigenicity Analyses of Fungal Isolates in Nuruk. THE KOREAN JOURNAL OF MYCOLOGY 2014. [DOI: 10.4489/kjm.2014.42.3.191] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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