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Shabeer S, Asad S, Jamal A, Ali A. Aflatoxin Contamination, Its Impact and Management Strategies: An Updated Review. Toxins (Basel) 2022; 14:307. [PMID: 35622554 PMCID: PMC9147583 DOI: 10.3390/toxins14050307] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 04/21/2022] [Accepted: 04/21/2022] [Indexed: 01/10/2023] Open
Abstract
Aflatoxin, a type of mycotoxin, is mostly produced by Aspergillus flavus and Aspergillus parasiticus. It is responsible for the loss of billions of dollars to the world economy, by contaminating different crops such as cotton, groundnut, maize, and chilies, and causing immense effects on the health of humans and animals. More than eighteen different types of aflatoxins have been reported to date, and among them, aflatoxins B1, B2, G1, and G2 are the most prevalent and lethal. Early detection of fungal infection plays a key role in the control of aflatoxin contamination. Therefore, different methods, including culture, chromatographic techniques, and molecular assays, are used to determine aflatoxin contamination in crops and food products. Many countries have set a maximum limit of aflatoxin contamination (2-20 ppb) in their food and agriculture commodities for human or animal consumption, and the use of different methods to combat this menace is essential. Fungal infection mostly takes place during the pre- and post-harvest stage of crops, and most of the methods to control aflatoxin are employed for the latter phase. Studies have shown that if correct measures are adopted during the crop development phase, aflatoxin contamination can be reduced by a significant level. Currently, the use of bio-pesticides is the intervention employed in many countries, whereby atoxigenic strains competitively reduce the burden of toxigenic strains in the field, thereby helping to mitigate this problem. This updated review on aflatoxins sheds light on the sources of contamination, and the on occurrence, impact, detection techniques, and management strategies, with a special emphasis on bio-pesticides to control aflatoxins.
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Affiliation(s)
- Saba Shabeer
- Crop Diseases Research Institute, National Agricultural Research Centre, Park Road, Islamabad 45500, Pakistan; (S.S.); (S.A.)
| | - Shahzad Asad
- Crop Diseases Research Institute, National Agricultural Research Centre, Park Road, Islamabad 45500, Pakistan; (S.S.); (S.A.)
| | - Atif Jamal
- Crop Diseases Research Institute, National Agricultural Research Centre, Park Road, Islamabad 45500, Pakistan; (S.S.); (S.A.)
| | - Akhtar Ali
- Department of Biological Science, The University of Tulsa, Tulsa, OK 74104, USA
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Silva JJ, Fungaro MHP, Soto TS, Taniwaki MH, Iamanaka BT. Low-cost, specific PCR assays to identify the main aflatoxigenic species of Aspergillus section Flavi. METHODS IN MICROBIOLOGY 2022; 196:106470. [PMID: 35447279 DOI: 10.1016/j.mimet.2022.106470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 03/26/2022] [Accepted: 04/12/2022] [Indexed: 01/10/2023]
Abstract
Aflatoxins are fungal metabolites that are present as contaminants in food globally. Most aflatoxigenic species belong to Aspergillus section Flavi, and the main ones are grouped in the A. flavus clade, where many cryptic species that are difficult to discriminate are found. In this study, we investigated inter- and intraspecific diversity of the A. flavus clade to develop low-cost, species-specific PCR assays for identifying aflatoxigenic species. A total of 269 sequences of the second largest subunit of RNA polymerase II (RPB2) locus were retrieved from GenBank, and primer pairs were designed using data mining to identify A. flavus, A. parasiticus, and A. novoparasiticus. Species-specific amplicons of approximately 620, 350, and 860 bp enabled identification of target species as A. flavus, A. parasiticus, and A. novoparasiticus, respectively.
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Affiliation(s)
- Josué J Silva
- Institute of Food Technology - ITAL, Campinas, SP, Brazil.
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Mahata PK, Dass RS, Pan A, Muthusamy B. Substantive Morphological Descriptions, Phylogenetic Analysis and Single Nucleotide Polymorphisms of Aspergillus Species From Foeniculum vulgare. Front Microbiol 2022; 13:832320. [PMID: 35250948 PMCID: PMC8894770 DOI: 10.3389/fmicb.2022.832320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 01/24/2022] [Indexed: 01/10/2023] Open
Abstract
Ascomycetous fungi are found associated with a wide variety of substrates which range from fresh water to marine ecosystems, tropical to temperate forest soils and deserts, throughout the world over. These demystifying fungi exist as endophytes, pathogens and saprobes. They have been studied due to their ability to contaminate foods and feedstuffs, causing an elaboration of mycotoxins. The objectives of the study included extensive analyses of the morphological features of fungi, especially Aspergilli, which have been presented while studying them on specific mycological media. It is also an elaborate compilation of substantive macro- and micro-morphological characterization of different Aspergilli isolated from the spice Foeniculum vulgare used in India and other countries in the world. Further, a first of its kind attempt has been made to study their relative abundance and frequency of occurrence, molecular phylogeny and genetic relatedness to characterize the Aspergilli into specific sections, groups and clades. Single nucleotide polymorphism (SNP) analysis was carried out to evaluate the functional consequences of nucleotide variations, synonymous and non-synonymous mutations in the protein structure. The study resulted in a total of 3,506 Aspergillus isolates, which were obtained from seventy (70) fennel samples, representing 14 Aspergillus species. The two most frequently found species were A. niger and A. flavus with a relative abundance of 32.24 and 11.63%, respectively. The taxonomy and current placements have been reappraised with suggestions and prospects for future research from six sections namely Terrei, Flavi, Fumigati, Nidulantes, Nigri, and Versicolores. In addition, a total number of 27 isolates were studied and deposited at the National Centre for Biotechnology Information (NCBI) and five Aspergillus species have been identified and are being reported for the first time from the fennel seeds, based on partial sequence analysis of the official fungal barcode namely, Internal Transcribed Spacer (ITS) and a functional gene, beta tubulin gene locus, coupled with phenotypic characterization. SNPs for specific DNA regions have been used to identify variants in Aspergilli obtained from Indian fennel seeds for the first time. The need for a polyphasic approach of morphological identification and genetic characterization of Aspergilli from Foeniculum vulgare is addressed and presented here in adequate detail. Our current work makes extensive use of partial beta-tubulin gene sequences analyses to evaluate the association between SNPs in five Aspergillus species sections.
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Affiliation(s)
- Pranab Kumar Mahata
- Fungal Genetics and Mycotoxicology Laboratory, Department of Microbiology, School of Life Sciences, Pondicherry University, Pondicherry, India
| | - Regina Sharmila Dass
- Fungal Genetics and Mycotoxicology Laboratory, Department of Microbiology, School of Life Sciences, Pondicherry University, Pondicherry, India
- *Correspondence: Regina Sharmila Dass,
| | - Archana Pan
- Centre for Bioinformatics, School of Life Sciences, Pondicherry University, Pondicherry, India
| | - Babylakshmi Muthusamy
- Institute of Bioinformatics, International Tech Park, Bengaluru, India
- Manipal Academy of Higher Education, Manipal, India
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Nikolić M, Savić I, Nikolić A, Jauković M, Kandić V, Stevanović M, Stanković S. Toxigenic Species Aspergillus parasiticus Originating from Maize Kernels Grown in Serbia. Toxins (Basel) 2021; 13:toxins13120847. [PMID: 34941685 PMCID: PMC8704542 DOI: 10.3390/toxins13120847] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/11/2021] [Accepted: 11/12/2021] [Indexed: 01/10/2023] Open
Abstract
In Serbia, aspergillus ear rot caused by the disease pathogen Aspergillus parasiticus (A. parasiticus) was first detected in 2012 under both field and storage conditions. Global climate shifts, primarily warming, favour the contamination of maize with aflatoxins in temperate climates, including Serbia. A five-year study (2012-2016) comprising of 46 A. parasiticus strains isolated from maize kernels was performed to observe the morphological, molecular, pathogenic, and toxigenic traits of this pathogen. The HPLC method was applied to evaluate mycotoxin concentrations in this causal agent. The A. parasiticus isolates synthesised mainly aflatoxin AFB1 (84.78%). The percentage of isolates synthesising aflatoxin AFG1 (15.22%) was considerably lower. Furthermore, the concentration of AFG1 was higher than that of AFB1 in eight isolates. The polyphase approach, used to characterise isolates, showed that they were A. parasiticus species. This identification was verified by the multiplex RLFP-PCR detection method with the use of restriction enzymes. These results form an excellent baseline for further studies with the aim of application in the production, processing, and storage of cereal grains and seeds, and in technological processes to ensure the safe production of food and feed.
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Affiliation(s)
- Milica Nikolić
- Maize Research Institute Zemun Polje, 11185 Belgrade, Serbia; (I.S.); (A.N.); (V.K.); (M.S.); (S.S.)
- Correspondence:
| | - Iva Savić
- Maize Research Institute Zemun Polje, 11185 Belgrade, Serbia; (I.S.); (A.N.); (V.K.); (M.S.); (S.S.)
| | - Ana Nikolić
- Maize Research Institute Zemun Polje, 11185 Belgrade, Serbia; (I.S.); (A.N.); (V.K.); (M.S.); (S.S.)
| | | | - Vesna Kandić
- Maize Research Institute Zemun Polje, 11185 Belgrade, Serbia; (I.S.); (A.N.); (V.K.); (M.S.); (S.S.)
| | - Milan Stevanović
- Maize Research Institute Zemun Polje, 11185 Belgrade, Serbia; (I.S.); (A.N.); (V.K.); (M.S.); (S.S.)
| | - Slavica Stanković
- Maize Research Institute Zemun Polje, 11185 Belgrade, Serbia; (I.S.); (A.N.); (V.K.); (M.S.); (S.S.)
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Development of an on-spot and rapid recombinase polymerase amplification assay for Aspergillus flavus detection in grains. Food Control 2021. [DOI: 10.1016/j.foodcont.2021.107957] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Development of PCR, LAMP and qPCR Assays for the Detection of Aflatoxigenic Strains of Aspergillus flavus and A. parasiticus in Hazelnut. Toxins (Basel) 2020; 12:toxins12120757. [PMID: 33266343 PMCID: PMC7761073 DOI: 10.3390/toxins12120757] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 11/23/2020] [Accepted: 11/26/2020] [Indexed: 01/10/2023] Open
Abstract
Aspergillus flavus and A. parasiticus are two species able to produce aflatoxins in foodstuffs, and in particular in hazelnuts, at harvest and during postharvest phase. As not all the strains of these species are aflatoxin producers, it is necessary to develop techniques that can detect aflatoxigenic from not aflatoxigenic strains. Two assays, a LAMP (loop-mediated isothermal amplification) and a real time PCR with TaqMan® probe were designed and validated in terms of specificity, sensitivity, reproducibility, and repeatability. The capability of the strains to produce aflatoxins was measured in vitro and both assays showed to be specific for the aflatoxigenic strains of A. flavus and A. parasiticus. The limit of detection of the LAMP assay was 100–999 picograms of DNA, while the qPCR detected 160 femtograms of DNA in hazelnuts. Both techniques were validated using artificially inoculated hazelnuts and naturally infected hazelnuts. The qPCR was able to detect as few as eight cells of aflatoxigenic Aspergillus in naturally infected hazelnut. The combination of the LAMP assay, which can be performed in less than an hour, as screening method, with the high sensitivity of the qPCR, as confirmation assay, is able to detect aflatoxigenic strains already in field, helping to preserve the food safety of hazelnuts.
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Albakri AH, Al-Shuhaib MBS, Alwan SL, AbdulAzeez S, Borgio JF. Deleterious missense variants in the aflatoxin biosynthesis genes explain the low toxicity of Aspergillus flavus from infected rice. Microb Pathog 2020; 152:104605. [PMID: 33166617 DOI: 10.1016/j.micpath.2020.104605] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 09/23/2020] [Accepted: 11/02/2020] [Indexed: 01/10/2023]
Abstract
Aspergillus flavus is one of the most natural contaminants of the improperly stored rice grains. It produces several secondary metabolites, like aflatoxins, which are well known hepatotoxic, hepatocarcinogenic and mutagenic agents. This study describes the in silico consequences of the missense mutations identified in several genes of aflatoxins biosynthesis in rice-contaminating A. flavus isolates. In the in vitro portion of the study, aflatoxins production profile was measured, and PCR-single strand-conformation polymorphism (SSCP)-sequencing method was used to genotype the studied genetic loci: aflP, aflM, aflR, PEP, and cob. Results showed aflatoxigenic potential in 79 out of 109 A. flavus isolates. Twenty-two missense and fifty-five synonymous mutations were found to be distributed variably on the studied loci. In the in silico portion of this study, several computations were utilized to predict the effect of each observed missense mutation on proteins structure, function, and stability. Seven mutations (O-methyl transferase: p.G256C; ver-1 dehydrogenase: p.K179 N and p.V183L; aspergillopepsin-1: p.P137L, p.S138F, p.G154C, and p.S158C) were found to be highly deleterious among the missense variants with damaging effects on their proteins' structure and function. In contrast to these detected variations in the aflatoxigenic loci, all missense mutations in the control non-aflatoxigenic cob gene were found to be neutral. These findings indicated that the observed mutations may reduce the concomitant biohazard of their biosynthesized aflatoxins. The current findings suggest that the naturally available variants may reduce or eliminates the dangerous consequences of aflatoxins upon ingesting the rice infected with A. flavus. To the best of our knowledge, this study is the first comprehensive report to analyze the missense mutations on the aflatoxin biosynthesis genes using in vitro and the state-of-art bio-computational tools.
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Affiliation(s)
- Ali H Albakri
- Department of Plant Protection, College of Agriculture, University of Kufa, Al-Kufa, Najaf, 54001, Iraq.
| | - Mohammed Baqur S Al-Shuhaib
- Department of Animal Production, College of Agriculture, Al-Qasim Green University, Al-Qasim, Babil, 51001, Iraq.
| | - Sabah L Alwan
- Department of Plant Protection, College of Agriculture, University of Kufa, Al-Kufa, Najaf, 54001, Iraq.
| | - Sayed AbdulAzeez
- Department of Genetic Research, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
| | - J Francis Borgio
- Department of Genetic Research, Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
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Rahman HU, Yue X, Yu Q, Zhang W, Zhang Q, Li P. Current PCR-based methods for the detection of mycotoxigenic fungi in complex food and feed matrices. WORLD MYCOTOXIN J 2020. [DOI: 10.3920/wmj2019.2455] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Mycotoxins are toxic secondary fungal metabolites produced by certain types of filamentous fungi, such as Aspergillus, Fusarium, and Penicillium spp. Mycotoxigenic fungi and their produced mycotoxins are considered to be an important issue in food and feed safety due to their toxic effects like carcinogenicity, immunosuppression, neurotoxicity, nephrotoxicity, and hepatotoxicity on humans and animals. To boost the safety level of food and feedstuff, detection and identification of toxins are essential at critical control points across food and feed chains. Zero-tolerance policies by the European Union and other organizations about the extreme low level of tolerance of mycotoxins contamination in food and feed matrices have led to an increasing interest to design more sensitive, specific, rapid, cost-effective, and safer to use mycotoxigenic fungi detection technologies. Hence, many mycotoxigenic fungi detection technologies have been applied to measure and control toxins contamination in food and feed substrates. PCR-based mycotoxigenic fungi detection technologies, such as conventional PCR, real-time PCR, nested PCR, reverse transcriptase (RT)-PCR, loop-mediated isothermal amplification (LAMP), in situ PCR, polymerase chain reaction-denaturing gradient gel electrophoresis (PCR DGGE), co-operational PCR, multiplex PCR, DNA arrays, magnetic capture-hybridization (MCH)-PCR and restriction fragment length polymorphism (RFLP), would contribute to our understanding about different mycotoxigenic fungi detection approaches and will enhance our capability about mycotoxigenic fungi identification, isolation and characterization at critical control points across food and feed chains. We have assessed the principles, results, the limit of detection, and application of these PCR-based detection technologies to alleviate mycotoxins contamination problem in complex food and feed substrates. The potential application of these detection technologies can reduce mycotoxins in complex food and feed matrices.
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Affiliation(s)
- H. Ur Rahman
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China P.R
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, China P.R
- Key Laboratory of Detection for Mycotoxins, Ministry of Agriculture, Wuhan 430062, China P.R
| | - X. Yue
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China P.R
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, China P.R
- Laboratory of Quality & Safety Risk Assessment for Oilseeds Products, Wuhan, Ministry of Agriculture, Wuhan 430062, China P.R
| | - Q. Yu
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China P.R
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, China P.R
- Key Laboratory of Detection for Mycotoxins, Ministry of Agriculture, Wuhan 430062, China P.R
- National Reference Laboratory for Agricultural Testing (Biotoxin), Wuhan 430062, China P.R
| | - W. Zhang
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China P.R
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, China P.R
- Quality Inspection and Test Center for Oilseeds Products, Ministry of Agriculture, Wuhan 430062, China P.R
| | - Q. Zhang
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China P.R
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, China P.R
- Laboratory of Quality & Safety Risk Assessment for Oilseeds Products, Wuhan, Ministry of Agriculture, Wuhan 430062, China P.R
| | - P. Li
- Oil Crops Research Institute, Chinese Academy of Agricultural Sciences, Wuhan 430062, China P.R
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan 430062, China P.R
- Key Laboratory of Detection for Mycotoxins, Ministry of Agriculture, Wuhan 430062, China P.R
- Laboratory of Quality & Safety Risk Assessment for Oilseeds Products, Wuhan, Ministry of Agriculture, Wuhan 430062, China P.R
- National Reference Laboratory for Agricultural Testing (Biotoxin), Wuhan 430062, China P.R
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Al-Shuhaib MBS, Albakri AH, Alwan SH, Almandil NB, AbdulAzeez S, Borgio JF. Optimal pcr primers for rapid and accurate detection of Aspergillus flavus isolates. Microb Pathog 2018; 116:351-355. [PMID: 29427712 DOI: 10.1016/j.micpath.2018.01.049] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/22/2018] [Accepted: 01/28/2018] [Indexed: 01/10/2023]
Abstract
Aspergillus flavus is among the most devastating opportunistic pathogens of several food crops including rice, due to its high production of carcinogenic aflatoxins. The presence of these organisms in economically important rice strip farming is a serious food safety concern. Several polymerase chain reaction (PCR) primers have been designed to detect this species; however, a comparative assessment of their accuracy has not been conducted. This study aims to identify the optimal diagnostic PCR primers for the identification of A. flavus, among widely available primers. We isolated 122 A. flavus native isolates from randomly collected rice strips (N = 300). We identified 109 isolates to the genus level using universal fungal PCR primer pairs. Nine pairs of primers were examined for their PCR diagnostic specificity on the 109 isolates. FLA PCR was found to be the optimal PCR primer pair for specific identification of the native isolates, over aflP(1), aflM, aflA, aflD, aflP(3), aflP(2), and aflR. The PEP primer pair was found to be the most unsuitable for A. flavus identification. In conclusion, the present study indicates the powerful specificity of the FLA PCR primer over other commonly available diagnostic primers for accurate, rapid, and large-scale identification of A. flavus native isolates. This study provides the first simple, practical comparative guide to PCR-based screening of A. flavus infection in rice strips.
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Affiliation(s)
- Mohammed Baqur S Al-Shuhaib
- Department of Animal Production, College of Agriculture, Al-Qasim Green University, Al-Qasim 51013, Babil, Iraq.
| | - Ali H Albakri
- Department of Plant Protection, College of Agriculture, University of Kufa, Al-Kufa, Najaf 54001, Iraq.
| | - Sabah H Alwan
- Department of Plant Protection, College of Agriculture, University of Kufa, Al-Kufa, Najaf 54001, Iraq.
| | - Noor B Almandil
- Department of Clinical Pharmacy Research, Institute for Research and Medical Consultation (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
| | - Sayed AbdulAzeez
- Department of Genetic Research, Institute for Research and Medical Consultation (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
| | - J Francis Borgio
- Department of Genetic Research, Institute for Research and Medical Consultation (IRMC), Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia.
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LAMP-based group specific detection of aflatoxin producers within Aspergillus section Flavi in food raw materials, spices, and dried fruit using neutral red for visible-light signal detection. Int J Food Microbiol 2017; 266:241-250. [PMID: 29272724 DOI: 10.1016/j.ijfoodmicro.2017.12.013] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Revised: 12/13/2017] [Accepted: 12/14/2017] [Indexed: 01/10/2023]
Abstract
Aflatoxins can be produced by 21 species within sections Flavi (16 species), Ochraceorosei (2), and Nidulantes (3) of the fungal genus Aspergillus. They pose risks to human and animal health due to high toxicity and carcinogenicity. Detecting aflatoxin producers can help to assess toxicological risks associated with contaminated commodities. Species specific molecular assays (PCR and LAMP) are available for detection of major producers, but fail to detect species of minor importance. To enable rapid and sensitive detection of several aflatoxin producing species in a single analysis, a nor1 gene-specific LAMP assay was developed. Specificity testing showed that among 128 fungal species from 28 genera, 15 aflatoxigenic species in section Flavi were detected, including synonyms of A. flavus and A. parasiticus. No cross reactions were found with other tested species. The detection limit of the assay was 9.03pg of A. parasiticus genomic DNA per reaction. Visual detection of positive LAMP reactions under daylight conditions was facilitated using neutral red to allow unambiguous distinction between positive and negative assay results. Application of the assay to the detection of A. parasiticus conidia revealed a detection limit of 211 conidia per reaction after minimal sample preparation. The usefulness of the assay was demonstrated in the analysis of aflatoxinogenic species in samples of rice, nuts, raisins, dried figs, as well as powdered spices. Comparison of LAMP results with presence/absence of aflatoxins and aflatoxin producing fungi in 50 rice samples showed good correlation between these parameters. Our study suggests that the developed LAMP assay is a rapid, sensitive and user-friendly tool for surveillance and quality control in our food industry.
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