1
|
El-Dawy EGAM, Gherbawy YA, Hussein MA. Characterization of Aspergillus section Flavi associated with stored grains. Mycotoxin Res 2024; 40:187-202. [PMID: 38231446 PMCID: PMC10834605 DOI: 10.1007/s12550-023-00514-1] [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: 07/13/2023] [Revised: 12/12/2023] [Accepted: 12/14/2023] [Indexed: 01/18/2024]
Abstract
Increased frequencies of Aspergillus section Flavi and aflatoxins in cereal grains have been seen in recent years due to changes in climate circumstances, such as high temperatures and drought. To assess the microbiological risks of contamination, it is critical to have a reliable and accurate means of identifying the fungi. The main goal of this study was to characterize Aspergillus species from section Flavi obtained from twenty-three samples of barley and maize grains, gathered from different markets in Qena, Egypt, using morphological and molecular techniques. Twenty-three isolates were chosen, one isolate from each sample; they were identified as A. aflatoxiformans (4 isolates), A. flavus (18), and A. parasiticus (1). The existence of four aflatoxin biosynthesis genes was also investigated in relation to the strains' ability to produce total aflatoxins and aflatoxin B1, focusing on the regulatory gene aflR and the structural genes aflD and aflM. All strains producing aflatoxins were linked to the presence of aflR1 and/or aflR2, except two isolates that exhibited aflatoxins but from which aflR1 or aflR2 were not detected, which may be due to one or more missing or unstudied additional genes involved in aflatoxin production. AflD and aflM genes were amplified by 10 and 9 isolates, respectively. Five samples of barley and maize were contaminated by aflatoxins. Fifteen isolates were positive for producing total aflatoxins in the range of 0.1-240 ppm. Antagonistic activity of Trichoderma viride against A. flavus (F5) was assessed at 31.3%. Trichoderma reduced total aflatoxins in all treated seeds, particularly those subjected to Trichoderma formulation.
Collapse
Affiliation(s)
- Eman G A M El-Dawy
- Botany and Microbiology Department, Faculty of Science, South Valley University, Qena, Egypt.
- Applied and Environmental Microbiology Center, South Valley University, Qena, Egypt.
| | - Youssuf A Gherbawy
- Botany and Microbiology Department, Faculty of Science, South Valley University, Qena, Egypt
- Applied and Environmental Microbiology Center, South Valley University, Qena, Egypt
| | - Mohamed A Hussein
- Botany and Microbiology Department, Faculty of Science, South Valley University, Qena, Egypt
- Applied and Environmental Microbiology Center, South Valley University, Qena, Egypt
| |
Collapse
|
2
|
Saad-Hussein A, Soliman KM, Moubarz G. 18S rRNA gene sequencing for environmental aflatoxigenic fungi and risk of hepatic carcinoma among exposed workers. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART A, TOXIC/HAZARDOUS SUBSTANCES & ENVIRONMENTAL ENGINEERING 2022; 57:174-182. [PMID: 35236253 DOI: 10.1080/10934529.2022.2046428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 02/11/2022] [Accepted: 02/17/2022] [Indexed: 06/14/2023]
Abstract
Aspergillus exposure causes an increase in aflatoxin (AF) levels among exposed workers thereby increasing their risk of developing hepatocellular carcinoma (HCC). This study attempted to determine the presence of airborne aflatoxigenic fungi in environment of waste water treatment plant (WWTP); and study the hepatic cancer risks among exposed workers, emphasizing the role of glutathione S-transferases (GST) gene polymorphism protecting against the risk of hepatic cancer development due to exposure to AFs. The study isolated and identified different Aspergillus species producing AFs in air samples from WWTP sites using 18S ribosomal ribonucleic acid (18S rRNA) gene sequencing technique. GST gene polymorphisms were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). A significant increase in blood AF levels was found among WWTP exposed workers. The occurrence of GSTT1& M1 gene polymorphism in 6% of the workers was accompanied by significant decrease in the levels of AFs and alpha fetoprotein (AFP). In conclusion, Aspergillus-producing AFs were found in air of WWTP. Continuous exposure to AF-producing fungi caused elevated AF-levels in exposed workers. However only workers with heterozygous GSTT1& M1 genotypes can detoxify AFs, thereby decreasing the risk of HCC development among exposed workers.
Collapse
Affiliation(s)
- Amal Saad-Hussein
- Environmental & Occupational Medicine Department, National Research Centre, Dokki, Cairo, Egypt
| | - Kawther M Soliman
- Food Toxicology and Contaminants Department, National Research Centre, Dokki, Cairo, Egypt
| | - Gehan Moubarz
- Environmental & Occupational Medicine Department, National Research Centre, Dokki, Cairo, Egypt
| |
Collapse
|
3
|
Ghanbari R, Rezaie S, Noorbakhsh F, Khaniki GJ, Soleimani M, Aghaee EM. Biocontrol effect of Kluyveromyces lactis on aflatoxin expression and production in Aspergillus parasiticus. FEMS Microbiol Lett 2020; 366:5499020. [PMID: 31132114 DOI: 10.1093/femsle/fnz114] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 05/25/2019] [Indexed: 12/11/2022] Open
Abstract
Aspergillus parasiticus is one of the most common fungi able to produce aflatoxins, which are naturally occurring carcinogenic substances. This study evaluated the effects of the safe yeast, Kluyveromyces lactis, on fungal growth, aflatoxin production and expression of aflR gene in A. parasiticus. Antifungal susceptibility was evaluated by exposing A. parasiticus to different amounts of K. lactis, and aflatoxin production was measured using high-performance liquid chromatography. Expression of the aflR gene was determined by measuring the cognate aflR mRNA level by quantitative real-time reverse-transcription polymerase chain reaction assay. The growth of A. parasiticus was inhibited by 7 days of incubation at 30°C with a minimum population of 1.5 × 105 CFU/ml of K. lactis, which also suppressed expression of the A. parasiticus aflR gene, reducing the total production of aflatoxins by 97.9% and aflatoxins B1, B2, G1 and G2 by 97.8, 98.6, 98 and 94%, respectively. Accordingly, K. lactis could be considered as a potential biocontrol agent against toxigenic molds in food and animal feed.
Collapse
Affiliation(s)
- Rooholla Ghanbari
- Food Safety & Hygiene Division, Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Poursina St., Qods Ave., Tehran, postal code:1417613151, Iran
| | - Sassan Rezaie
- Department of Medical Mycology & Parasitology, School of Public Health, Tehran University of Medical Sciences, Poursina St., Qods Ave., Tehran, postal code:1417613151, Iran
| | - Fatemeh Noorbakhsh
- Department of Microbiology, Biological Science College, Islamic Azad University, Varamin-Pishva Branch, 9 Dey Square, Pishva road, Varamin, Iran
| | - Gholamreza Jahed Khaniki
- Food Safety & Hygiene Division, Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Poursina St., Qods Ave., Tehran, postal code:1417613151, Iran
| | - Mina Soleimani
- Food Safety & Hygiene Division, Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Poursina St., Qods Ave., Tehran, postal code:1417613151, Iran
| | - Ebrahim Molaee Aghaee
- Food Safety & Hygiene Division, Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Poursina St., Qods Ave., Tehran, postal code:1417613151, Iran
| |
Collapse
|
4
|
Kjærbølling I, Vesth T, Frisvad JC, Nybo JL, Theobald S, Kildgaard S, Petersen TI, Kuo A, Sato A, Lyhne EK, Kogle ME, Wiebenga A, Kun RS, Lubbers RJM, Mäkelä MR, Barry K, Chovatia M, Clum A, Daum C, Haridas S, He G, LaButti K, Lipzen A, Mondo S, Pangilinan J, Riley R, Salamov A, Simmons BA, Magnuson JK, Henrissat B, Mortensen UH, Larsen TO, de Vries RP, Grigoriev IV, Machida M, Baker SE, Andersen MR. A comparative genomics study of 23 Aspergillus species from section Flavi. Nat Commun 2020; 11:1106. [PMID: 32107379 PMCID: PMC7046712 DOI: 10.1038/s41467-019-14051-y] [Citation(s) in RCA: 92] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2019] [Accepted: 12/02/2019] [Indexed: 02/01/2023] Open
Abstract
Section Flavi encompasses both harmful and beneficial Aspergillus species, such as Aspergillus oryzae, used in food fermentation and enzyme production, and Aspergillus flavus, food spoiler and mycotoxin producer. Here, we sequence 19 genomes spanning section Flavi and compare 31 fungal genomes including 23 Flavi species. We reassess their phylogenetic relationships and show that the closest relative of A. oryzae is not A. flavus, but A. minisclerotigenes or A. aflatoxiformans and identify high genome diversity, especially in sub-telomeric regions. We predict abundant CAZymes (598 per species) and prolific secondary metabolite gene clusters (73 per species) in section Flavi. However, the observed phenotypes (growth characteristics, polysaccharide degradation) do not necessarily correlate with inferences made from the predicted CAZyme content. Our work, including genomic analyses, phenotypic assays, and identification of secondary metabolites, highlights the genetic and metabolic diversity within section Flavi.
Collapse
Affiliation(s)
- Inge Kjærbølling
- Department of Biotechnology and Bioengineering, Technical University of Denmark, Søltoft Plads 223, 2800, Kongens Lyngby, Denmark
| | - Tammi Vesth
- Department of Biotechnology and Bioengineering, Technical University of Denmark, Søltoft Plads 223, 2800, Kongens Lyngby, Denmark
| | - Jens C Frisvad
- Department of Biotechnology and Bioengineering, Technical University of Denmark, Søltoft Plads 223, 2800, Kongens Lyngby, Denmark
| | - Jane L Nybo
- Department of Biotechnology and Bioengineering, Technical University of Denmark, Søltoft Plads 223, 2800, Kongens Lyngby, Denmark
| | - Sebastian Theobald
- Department of Biotechnology and Bioengineering, Technical University of Denmark, Søltoft Plads 223, 2800, Kongens Lyngby, Denmark
| | - Sara Kildgaard
- Department of Biotechnology and Bioengineering, Technical University of Denmark, Søltoft Plads 223, 2800, Kongens Lyngby, Denmark
| | - Thomas Isbrandt Petersen
- Department of Biotechnology and Bioengineering, Technical University of Denmark, Søltoft Plads 223, 2800, Kongens Lyngby, Denmark
| | - Alan Kuo
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Atsushi Sato
- Kikkoman Corporation, 250 Noda, 278-0037, Noda, Japan
| | - Ellen K Lyhne
- Department of Biotechnology and Bioengineering, Technical University of Denmark, Søltoft Plads 223, 2800, Kongens Lyngby, Denmark
| | - Martin E Kogle
- Department of Biotechnology and Bioengineering, Technical University of Denmark, Søltoft Plads 223, 2800, Kongens Lyngby, Denmark
| | - Ad Wiebenga
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | - Roland S Kun
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | - Ronnie J M Lubbers
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | - Miia R Mäkelä
- Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, Helsinki, Finland
| | - Kerrie Barry
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Mansi Chovatia
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Alicia Clum
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Chris Daum
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Sajeet Haridas
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Guifen He
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Kurt LaButti
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Anna Lipzen
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Stephen Mondo
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Jasmyn Pangilinan
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Robert Riley
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Asaf Salamov
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Blake A Simmons
- US Department of Energy Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA
| | - Jon K Magnuson
- US Department of Energy Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, (CNRS UMR 7257, Aix-Marseille University, 163 Avenue de Luminy, Parc Scientifique et Technologique de Luminy, 13288, Marseille, France
| | - Uffe H Mortensen
- Department of Biotechnology and Bioengineering, Technical University of Denmark, Søltoft Plads 223, 2800, Kongens Lyngby, Denmark
| | - Thomas O Larsen
- Department of Biotechnology and Bioengineering, Technical University of Denmark, Søltoft Plads 223, 2800, Kongens Lyngby, Denmark
| | - Ronald P de Vries
- Fungal Physiology, Westerdijk Fungal Biodiversity Institute & Fungal Molecular Physiology, Utrecht University, Uppsalalaan 8, 3584 CT, Utrecht, The Netherlands
| | - Igor V Grigoriev
- US Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
- Department of Plant and Microbial Biology, University of California, 111 Koshland Hall, Berkeley, CA, 94720, USA
| | - Masayuki Machida
- Kanazawa Institute of Technology, 3 Chome-1, 924-0838 Yatsukaho, Hakusan-shi, Ishikawa-ken, Japan
| | - Scott E Baker
- US Department of Energy Joint BioEnergy Institute, 5885 Hollis St., Emeryville, CA, 94608, USA
- Environmental Molecular Sciences Division, Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, 902 Battelle Blvd, Richland, WA, 99354, USA
| | - Mikael R Andersen
- Department of Biotechnology and Bioengineering, Technical University of Denmark, Søltoft Plads 223, 2800, Kongens Lyngby, Denmark.
| |
Collapse
|
5
|
Quirk JT, Kupinski JM. Interspecific mitochondrial DNA restriction fragment length polymorphisms inAspergillussectionFlavi. Mycologia 2017. [DOI: 10.1080/15572536.2003.11833164] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Jeffrey T. Quirk
- Edinboro University of Pennsylvania, Department of Biology and Health Service, Edinboro, PA 16444
| | - John M. Kupinski
- Department of Biology, St. Bonaventure University, St. Bonaventure, New York 14778
| |
Collapse
|
6
|
NATEGHI F, NOORBAKHSH F, LOTFALI E, REZAIE S. Investigation the Effects of Lactobacillus acidophilus and Lactobacillus casei on aflR Gene expression in Aspergillus parasiticus by Real Time-PCR. IRANIAN JOURNAL OF PUBLIC HEALTH 2016; 45:781-6. [PMID: 27648422 PMCID: PMC5026834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND The effect of probiotic bacteria (Lactobacillus acidophilus and L. casei) as safe organisms was examined on fungal growth and aflatoxin gene regulation in Aspergillus parasiticus. METHODS The fungus was cultured in presence of two different concentrations of L. acidophilus and L. casei in MRS broth medium. Mycelia dry weight is indicated as criteria to evaluate fungal growth. Besides, investigation of aflR gene expression by Real Time PCR was performed for analysis of gene regulatory effects in aflatoxin biosynthetic pathway. RESULTS Both Lactobacillus strongly inhibited fungal growth in the concentrations of 1. 5×10(2), [Formula: see text] . Expression analysis of aflatoxin genes pathway by real time PCR showed inhibitory effect of L. acidophilus and L. casei on expression of aflR gene. The gene expression revealed to be reduced at the approximate rates of 99. 7% and 98% respectively by L. acidopholus and L. casei in concentrations of [Formula: see text] and more. CONCLUSION L. acidophilus and L. casei may be used successfully as suitable candidates in controlling of A. parasiticus growth on food and feed as well as reducing of aflatoxin contamination.
Collapse
Affiliation(s)
- Farzaneh NATEGHI
- Division of Microbiology, Dept. of Biology, Islamic Azad University, Varamin-Pishva Branch, Varamin, Iran
| | - Fatemeh NOORBAKHSH
- Division of Microbiology, Dept. of Biology, Islamic Azad University, Varamin-Pishva Branch, Varamin, Iran,Corresponding Author:
| | - Ensieh LOTFALI
- Division of Molecular Biology, Dept. of Medical Mycology & Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| | - Sassan REZAIE
- Division of Molecular Biology, Dept. of Medical Mycology & Parasitology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
7
|
Diba K, Mirhendi H, Kordbacheh P, Rezaie S. Development of RFLP-PCR method for the identification of medically important Aspergillus species using single restriction enzyme MwoI. Braz J Microbiol 2014; 45:503-7. [PMID: 25242934 PMCID: PMC4166275 DOI: 10.1590/s1517-83822014000200018] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2012] [Accepted: 03/14/2014] [Indexed: 11/21/2022] Open
Abstract
In this study we attempted to modify the PCR-RFLP method using restriction enzyme MwoI for the identification of medically important Aspergillus species. Our subjects included nine standard Aspergillus species and 205 Aspergillus isolates of approved hospital acquired infections and hospital indoor sources. First of all, Aspergillus isolates were identified in the level of species by using morphologic method. A twenty four hours culture was performed for each isolates to harvest Aspergillus mycelia and then genomic DNA was extracted using Phenol-Chloroform method. PCR-RFLP using single restriction enzyme MwoI was performed in ITS regions of rDNA gene. The electrophoresis data were analyzed and compared with those of morphologic identifications. Total of 205 Aspergillus isolates included 153 (75%) environmental and 52 (25%) clinical isolates. A. flavus was the most frequently isolate in our study (55%), followed by A. niger 65(31.7%), A. fumigatus 18(8.7%), A. nidulans and A. parasiticus 2(1% each). MwoI enabled us to discriminate eight medically important Aspergillus species including A. fumigatus, A. niger, A. flavus as the most common isolated species. PCR-RFLP method using the restriction enzyme MwoI is a rapid and reliable test for identification of at least the most medically important Aspergillus species.
Collapse
Affiliation(s)
- K. Diba
- Cellular and Molecular Research CenterSchool of MedicineUrmia University of Medical SciencesUrmiaWest AzarbayejanIranCellular and Molecular Research Center, School of Medicine, Urmia University of Medical Sciences, Urmia, West Azarbayejan, Iran.
| | - H. Mirhendi
- Department of Parasitology and MycologySchool of Public Health and Institute of Public Health ResearchTehran University of Medical SciencesTehranIranDepartment of Parasitology and Mycology, School of Public Health and Institute of Public Health Research, Tehran University of Medical Sciences, Tehran, Iran.
| | - P. Kordbacheh
- Department of Parasitology and MycologySchool of Public Health and Institute of Public Health ResearchTehran University of medical sciencesTehranIranDepartment of Parasitology and Mycology, School of Public Health and Institute of Public Health Research, Tehran University of medical sciences, Tehran, Iran.
| | - S. Rezaie
- Department of Parasitology and MycologySchool of Public Health and Institute of Public Health ResearchTehran University of medical sciencesTehranIranDepartment of Parasitology and Mycology, School of Public Health and Institute of Public Health Research, Tehran University of medical sciences, Tehran, Iran.
| |
Collapse
|
8
|
Midorikawa GEO, de Sousa MDLM, Freitas Silva O, Dias JDSA, Kanzaki LIB, Hanada RE, Mesquita RMLC, Gonçalves RC, Alvares VS, Bittencourt DMC, Miller RNG. Characterization of Aspergillus species on Brazil nut from the Brazilian Amazonian region and development of a PCR assay for identification at the genus level. BMC Microbiol 2014; 14:138. [PMID: 24885088 PMCID: PMC4051963 DOI: 10.1186/1471-2180-14-138] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 05/23/2014] [Indexed: 01/29/2023] Open
Abstract
Background Brazil nut is a protein-rich extractivist tree crop in the Amazon region. Fungal contamination of shells and kernel material frequently includes the presence of aflatoxigenic Aspergillus species from the section Flavi. Aflatoxins are polyketide secondary metabolites, which are hepatotoxic carcinogens in mammals. The objectives of this study were to identify Aspergillus species occurring on Brazil nut grown in different states in the Brazilian Amazon region and develop a specific PCR method for collective identification of member species of the genus Aspergillus. Results Polyphasic identification of 137 Aspergillus strains isolated from Brazil nut shell material from cooperatives across the Brazilian Amazon states of Acre, Amapá and Amazonas revealed five species, with Aspergillus section Flavi species A. nomius and A. flavus the most abundant. PCR primers ASP_GEN_MTSSU_F1 and ASP_GEN_MTSSU_R1 were designed for the genus Aspergillus, targeting a portion of the mitochondrial small subunit ribosomal RNA gene. Primer specificity was validated through both electronic PCR against target gene sequences at Genbank and in PCR reactions against DNA from Aspergillus species and other fungal genera common on Brazil nut. Collective differentiation of the observed section Flavi species A. flavus, A. nomius and A. tamarii from other Aspergillus species was possible on the basis of RFLP polymorphism. Conclusions Given the abundance of Aspergillus section Flavi species A. nomius and A. flavus observed on Brazil nut, and associated risk of mycotoxin accumulation, simple identification methods for such mycotoxigenic species are of importance for Hazard Analysis Critical Control Point system implementation. The assay for the genus Aspergillus represents progress towards specific PCR identification and detection of mycotoxigenic species.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Robert N G Miller
- Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brasília, Campus Universitário Darcy Ribeiro, CEP 70,910-900 Brasília D,F,, Brazil.
| |
Collapse
|
9
|
Priyanka S, Uppalapati S, Kingston J, Murali H, Batra H. Development of ISSR-derived SCAR marker-targeted PCR for identification of Aspergillus
section Flavi
members. Lett Appl Microbiol 2014; 58:414-22. [DOI: 10.1111/lam.12207] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2013] [Revised: 11/21/2013] [Accepted: 11/29/2013] [Indexed: 12/01/2022]
Affiliation(s)
- S.R. Priyanka
- Defence Food Research Laboratory; Siddarthnagar Mysore Karnataka India
| | - S.R. Uppalapati
- Defence Food Research Laboratory; Siddarthnagar Mysore Karnataka India
| | - J.J. Kingston
- Defence Food Research Laboratory; Siddarthnagar Mysore Karnataka India
| | - H.S. Murali
- Defence Food Research Laboratory; Siddarthnagar Mysore Karnataka India
| | - H.V. Batra
- Defence Food Research Laboratory; Siddarthnagar Mysore Karnataka India
| |
Collapse
|
10
|
Refojo N, Duarte-Escalante E, Dignani MC, Hevia AI, Abrantes RA, Davel G, Canteros C, Frías de León MG, Acosta-Altamirano G, Zúñiga G, Reyes-Montes MDR. [Genotyping of clinical isolates of Aspergillus flavus and its relationship with environmental isolates of an oncohematological center]. Rev Iberoam Micol 2012; 30:25-30. [PMID: 23036749 DOI: 10.1016/j.riam.2012.09.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2012] [Revised: 08/09/2012] [Accepted: 09/10/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND During 4 months, and while conducting an environmental sampling of air, 2 cases of aspergillosis by Aspergillus flavus (A. flavus) were diagnosed at an oncohematological center in Buenos Aires, Argentina. AIMS The aim of this study was to know the variability and the genetic relationship between the clinical and environmental isolates, obtained in the oncohematological center. METHODS Two genotyping techniques of different discriminatory power (RAPD and AFLP) were used. A genetic similarity matrix was calculated using Jaccard method and was the basis for the construction of a dendrogram by UPGMA. The level of genetic variability was assessed by measuring the percentage of polymorphic loci, number of effective allele, expected heterocygozity and association index test (I(A)). RESULTS The dendrogram reveals that the A. flavus isolates recovered from the patients were not genetically related to those gotten from the rooms occupied by the patients. The environmental isolates had higher values of genetic diversity than the clinical isolates. The I(A) estimated for all the isolates suggest that recombination events occurred. CONCLUSIONS Patients 1 and 2 were not infected with isolates from the nosocomial environment. Clinical and environmental isolates of A. flavus showed high genetic variability among them.
Collapse
Affiliation(s)
- Nicolás Refojo
- Departamento de Micología, INEI ANLIS Dr. Carlos G. Malbrán, Buenos Aires, Argentina
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Leguizamón J, Hernández J, Murcia MI, Soto CY. Identification of potential biomarkers to distinguish Mycobacterium colombiense from other mycobacterial species. Mol Cell Probes 2012; 27:46-52. [PMID: 22967705 DOI: 10.1016/j.mcp.2012.08.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Revised: 08/10/2012] [Accepted: 08/17/2012] [Indexed: 10/27/2022]
Abstract
Mycobacterium avium complex (MAC) consists of 9 species of slow-growing mycobacteria with differing degrees of pathogenicity, host preference and environmental distribution. Mycobacterium colombiense is a novel member of MAC that is responsible for disseminated infections in HIV-infected patients in Colombia and lymphadenopathy cases in Europe. At present, methods to easily differentiate novel members of MAC are lacking. In this study, we identified possible biomarkers that are potentially useful for the detection of M. colombiense by PCR or chromatography. The Randomly Amplified Polymorphic DNA (RAPD) technique was used to amplify genomic fragments of M. colombiense CECT 3035 that were subsequently used in the development of a direct colony-specific PCR assay using specific primers. The designed primers amplified a 634-bp fragment of DNA from M. colombiense, which included a 450-bp genomic region that encodes a hypothetical protein of 149 amino acids that is exclusive to M. colombiense. Bioinformatic analyses revealed that this hypothetical protein had no signal peptide, active sites or functional domains to aid its identification or classification. In addition, using thin-layer chromatography, we identified a different profile of mycolates for M. colombiense strains. The test developed in this study has potential applications in the routine identification of M. colombiense and in molecular assays designed for the surveillance of MAC strains.
Collapse
Affiliation(s)
- John Leguizamón
- Chemistry Department, Faculty of Sciences, Universidad Nacional de Colombia, Carrera 30# 45-03, Ciudad Universitaria, Bogotá, Colombia
| | | | | | | |
Collapse
|
12
|
González AJ, Fernández AM, San José M, González-Varela G, Rodicio MR. A Pseudomonas viridiflava-related bacterium causes a dark-reddish spot disease in Glycine max. Appl Environ Microbiol 2012; 78:3756-8. [PMID: 22407694 PMCID: PMC3346376 DOI: 10.1128/aem.00223-12] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 03/02/2012] [Indexed: 11/20/2022] Open
Abstract
A virulent Pseudomonas viridiflava-related bacterium has been identified as a new pathogen of soybean, one of the most important crops worldwide. The bacterium was recovered from forage soybean leaves with dark-reddish spots, and damage on petioles and pods was also observed. In contrast, common bean was not affected.
Collapse
Affiliation(s)
- Ana J González
- Laboratorio de Fitopatología, Servicio Regional de Investigación y Desarrollo Agroalimentario (SERIDA), Villaviciosa, Asturias, Spain.
| | | | | | | | | |
Collapse
|
13
|
A review molecular typing methods for Aspergillus flavus isolates. Mycopathologia 2011; 172:83-93. [PMID: 21369748 DOI: 10.1007/s11046-011-9406-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2010] [Accepted: 02/16/2011] [Indexed: 10/18/2022]
Abstract
Aspergillus flavus is the second most important Aspergillus species causing human infections. The importance of this fungus increases in regions with a dry and hot climate. Small phylogenetic studies in Aspergillus flavus indicate that the morphological species contains several genetically isolated species. Different genotyping methods have been developed and employed in order to better understand the genetic and epidemiological relationships between environmental and clinical isolates. Understanding pathogen distribution and relatedness is essential for determining the epidemiology of nosocomial infections and aiding in the design of rational pathogen control methods. Typing techniques can also give us a deeper understanding of the colonization pattern in patients. Most of these studies focused on Aspergillus fumigatus because it is medically the most isolated species. To date, there has not been any publication exclusively reviewing the molecular typing techniques for Aspergillus flavus in the literature. This article reviews all these different available methods for this organism.
Collapse
|
14
|
Godet M, Munaut F. Molecular strategy for identification inAspergillus sectionFlavi. FEMS Microbiol Lett 2010; 304:157-68. [DOI: 10.1111/j.1574-6968.2009.01890.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
|
15
|
Genetic variability of aflatoxin B1 producing Aspergillus flavus strains isolated from discolored rice grains. World J Microbiol Biotechnol 2008. [DOI: 10.1007/s11274-008-9857-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
16
|
Barros GG, Chiotta ML, Reynoso MM, Torres AM, Chulze SN. Molecular characterization of Aspergillus section Flavi isolates collected from peanut fields in Argentina using AFLPs. J Appl Microbiol 2008; 103:900-9. [PMID: 17897192 DOI: 10.1111/j.1365-2672.2007.03312.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIMS The objectives of this study were: (i) to evaluate genetic relatedness among Aspergillus section Flavi strains isolated from soil and peanut seeds in Argentina; (ii) to determine if AFLP molecular markers could be useful to identify isolates up to species level, and to correlate these markers with the isolates' toxigenic potentials and/or vegetative compatibility group (VCG) affiliations. METHODS AND RESULTS Amplified fragment length polymorphism (AFLPs) analysis was applied to compare 82 isolates of Aspergillus section Flavi. Cluster analysis showed a clear separation of A. flavus and A. parasiticus, and comparison of fingerprints revealed several specific markers for each group of isolates. AFLP analysis indicates that no genotypical differences can be established between aflatoxigenic and nonaflatoxigenic producers in both species analysed. In addition, candidate AFLP markers associated with a particular VCG were not found. CONCLUSIONS There was a concordance between morphological identification and separation up to species level using molecular markers. The findings of specific bands for A. flavus and A. parasiticus may be useful for the design of specific PCR primers in order to differentiate these species and detect them in food. SIGNIFICANCE AND IMPACT OF THE STUDY The present study provides new data on molecular characterization of Aspergillus section Flavi in Argentina.
Collapse
Affiliation(s)
- G G Barros
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina.
| | | | | | | | | |
Collapse
|
17
|
Jørgensen TR. Identification and toxigenic potential of the industrially important fungi, Aspergillus oryzae and Aspergillus sojae. J Food Prot 2007; 70:2916-34. [PMID: 18095455 DOI: 10.4315/0362-028x-70.12.2916] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Mold strains belonging to the species Aspergillus oryzae and Aspergillus sojae are highly valued as koji molds in the traditional preparation of fermented foods, such as miso, sake, and shoyu, and as protein production hosts in modern industrial processes. A. oryzae and A. sojae are relatives of the wild molds Aspergillus flavus and Aspergillus parasiticus. All four species are classified to the A. flavus group. Strains of the A. flavus group are characterized by a high degree of morphological similarity. Koji mold species are generally perceived of as being nontoxigenic, whereas wild molds are associated with the carcinogenic aflatoxins. Thus, reliable identification of individual strains is very important for application purposes. This review considers the pheno- and genotypic markers used in the classification of A. flavus group strains and specifically in the identification of A. oryzae and A. sojae strains. Separation of A. oryzae and A. sojae from A. flavus and A. parasiticus, respectively, is inconsistent, and both morphologic and molecular evidence support conspecificity. The high degree of identity is reflected by the divergent identification of reference cultures maintained in culture collections. As close relatives of aflatoxin-producing wild molds, koji molds possess an aflatoxin gene homolog cluster. Some strains identified as A. oryzae and A. sojae have been implicated in aflatoxin production. Identification of a strain as A. oryzae or A. sojae is no guarantee of its inability to produce aflatoxins or other toxic metabolites. Toxigenic potential must be determined specifically for individual strains. The species taxa, A. oryzae and A. sojae, are currently conserved by societal issues.
Collapse
Affiliation(s)
- Thomas R Jørgensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
| |
Collapse
|
18
|
Chang PK, Matsushima K, Takahashi T, Yu J, Abe K, Bhatnagar D, Yuan GF, Koyama Y, Cleveland TE. Understanding nonaflatoxigenicity of Aspergillus sojae: a windfall of aflatoxin biosynthesis research. Appl Microbiol Biotechnol 2007; 76:977-84. [PMID: 17665189 DOI: 10.1007/s00253-007-1116-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2007] [Accepted: 07/07/2007] [Indexed: 10/23/2022]
Abstract
Aspergillus section Flavi includes aflatoxin-producing and nonproducing fungi. Aspergillus sojae is unable to produce aflatoxins and is generally recognized as safe for food fermentation. However, because of its taxonomical relatedness to aflatoxin-producing Aspergillus parasiticus and A. flavus, it is necessary to decipher the underlying mechanisms for its inability to produce aflatoxins. This review addresses the relationship between A. sojae and A. parasiticus and the advances that have been made in aflatoxin biosynthesis research, especially with regard to gene structure, genome organization, and gene regulation in A. parasiticus and A. flavus and how this has been used to assure the safety of A. sojae as an organism for food fermentation. The lack of aflatoxin-producing ability of A. sojae results primarily from an early termination point mutation in the pathway-specific aflR regulatory gene, which causes the truncation of the transcriptional activation domain of AflR and the abolishment of interaction between AflR and the AflJ co-activator. Both are required for gene expression. In addition, a defect in the polyketide synthase gene also contributes to its nonaflatoxigenicity.
Collapse
Affiliation(s)
- Perng-Kuang Chang
- Food and Feed Safety Research Unit, Southern Regional Research Center, Agricultural Research Service, US Department of Agriculture, 1100 Robert E. Lee Boulevard, New Orleans, LA 70124, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Barros G, Chiotta ML, Torres A, Chulze S. Genetic diversity in Aspergillus parasiticus population from the peanut agroecosystem in Argentina. Lett Appl Microbiol 2006; 42:560-6. [PMID: 16706892 DOI: 10.1111/j.1472-765x.2006.01878.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS The aims of this work were to identify potential sources of Aspergillus parasiticus inoculum and to evaluate the sclerotial and toxigenic profiles of this species from the peanut agroecosystem in Argentina. Likewise, the genetic diversity of A. parasiticus population was analysed using vegetative compatibility group (VCG) analysis. METHODS AND RESULTS The A. parasiticus strains were isolated from soil, debris and peanut seeds in Córdoba Province, Argentina. A. parasiticus was recovered from the three sources analysed. Only 11 of 185 A. parasiticus isolates (5.9%) did not produce aflatoxins, while 57% produced sclerotia. Twenty-four VCG were identified from 63 isolates. The VCG diversity index for A. parasiticus, expressed as the number of groups divided by the total number of isolates, was 0.31. In general, there were significant differences among VCG in aflatoxin production. CONCLUSIONS The presence of aflatoxigenic strains of A. parasiticus in the three substrates suggests that they may be an important source of aflatoxin in Argentina's peanut agroecosystem. The A. parasiticus population shows a low genetic diversity. SIGNIFICANCE AND IMPACT OF THE STUDY The present study showed data on inoculum distribution, aflatoxin and sclerotia production and genetic diversity in an A. parasiticus population isolated from the peanut agroecosystem in Argentina.
Collapse
Affiliation(s)
- G Barros
- Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas Físico Químicas y Naturales, Universidad Nacional de Río Cuarto, Río Cuarto, Córdoba, Argentina
| | | | | | | |
Collapse
|
20
|
Lee CZ, Liou GY, Yuan GF. Comparison of the aflR gene sequences of strains in Aspergillus section Flavi. MICROBIOLOGY-SGM 2006; 152:161-170. [PMID: 16385126 DOI: 10.1099/mic.0.27618-0] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Aflatoxins are polyketide-derived secondary metabolites produced by Aspergillus parasiticus, Aspergillus flavus, Aspergillus nomius and a few other species. The toxic effects of aflatoxins have adverse consequences for human health and agricultural economics. The aflR gene, a regulatory gene for aflatoxin biosynthesis, encodes a protein containing a zinc-finger DNA-binding motif. Although Aspergillus oryzae and Aspergillus sojae, which are used in fermented foods and in ingredient manufacture, have no record of producing aflatoxin, they have been shown to possess an aflR gene. This study examined 34 strains of Aspergillus section Flavi. The aflR gene of 23 of these strains was successfully amplified and sequenced. No aflR PCR products were found in five A. sojae strains or six strains of A. oryzae. These PCR results suggested that the aflR gene is absent or significantly different in some A. sojae and A. oryzae strains. The sequenced aflR genes from the 23 positive strains had greater than 96.6 % similarity, which was particularly conserved in the zinc-finger DNA-binding domain. The aflR gene of A. sojae has two obvious characteristics: an extra CTCATG sequence fragment and a C to T transition that causes premature termination of AFLR protein synthesis. Differences between A. parasiticus/A. sojae and A. flavus/A. oryzae aflR genes were also identified. Some strains of A. flavus as well as A. flavus var. viridis, A. oryzae var. viridis and A. oryzae var. effuses have an A. oryzae-type aflR gene. For all strains with the A. oryzae-type aflR gene, there was no evidence of aflatoxin production. It is suggested that for safety reasons, the aflR gene could be examined to assess possible aflatoxin production by Aspergillus section Flavi strains.
Collapse
Affiliation(s)
- Chao-Zong Lee
- Bioresource Collection and Research Center, Food Industry Research and Development Institute, PO Box 246, Hsinchu 300, Taiwan, ROC
| | - Guey-Yuh Liou
- Bioresource Collection and Research Center, Food Industry Research and Development Institute, PO Box 246, Hsinchu 300, Taiwan, ROC
| | - Gwo-Fang Yuan
- Bioresource Collection and Research Center, Food Industry Research and Development Institute, PO Box 246, Hsinchu 300, Taiwan, ROC
| |
Collapse
|
21
|
|
22
|
Montiel D, Dickinson MJ, Lee HA, Dyer PS, Jeenes DJ, Roberts IN, James S, Fuller LJ, Matsuchima K, Archer DB. Genetic differentiation of the Aspergillus section Flavi complex using AFLP fingerprints. ACTA ACUST UNITED AC 2004; 107:1427-34. [PMID: 15000243 DOI: 10.1017/s0953756203008797] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Twenty-four isolates of Aspergillus sojae, A. parasiticus, A. oryzae and A. flavus, including a number that have the capacity to produce aflatoxin, have been compared using amplified fragment length polymorphisms (AFLPs). Based on analysis of 12 different primer combinations, 500 potentially polymorphic fragments have been identified. Analysis of the AFLP data consistently and clearly separates the A. sojae/A. parasiticus isolates from the A. oryzae/A. flavus isolates. Furthermore. there are markers that can be used to distinguish the A. sojae isolates from those of A. parasiticus, which form the basis for species-specific markers. However, whilst there were many polymorphisms between isolates within the A. oryzae/A. flavus subgroup, no markers could be identified that distinguish between the two species. Sequencing of the ribosomal DNA ITS (internal transcribed spacers) from selected isolates also separated the A. sojae/A. parasiticus subgroup from the A. oryzae/A. flavus subgroup, but was unable to distinguish between the A. sojae and A. parasiticus isolates. Some ITS variation was found between isolates within the A. oryzae/A. flavus subgroup, but did not correlate with the species classification, indicating that it is difficult to use molecular data to separate the two species. In addition, sequencing of ribosomal ITS regions and AFLP analysis suggested that some species annotations in public culture collections may be inaccurate.
Collapse
Affiliation(s)
- Dolores Montiel
- School of Life and Environmental Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
| | | | | | | | | | | | | | | | | | | |
Collapse
|
23
|
Chen RS, Tsay JG, Huang YF, Chiou RYY. Polymerase chain reaction-mediated characterization of molds belonging to the Aspergillus flavus group and detection of Aspergillus parasiticus in peanut kernels by a multiplex polymerase chain reaction. J Food Prot 2002; 65:840-4. [PMID: 12030297 DOI: 10.4315/0362-028x-65.5.840] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The Aspergillus flavus group covers species of A. flavus and Aspergillus parasiticus as aflatoxin producers and Aspergillus oryzae and Aspergillus sojae as koji molds. Genetic similarity among these species is high, and aflatoxin production of a culture may be affected by cultivation conditions and substrate composition. Therefore, a polymerase chain reaction (PCR)-mediated method of detecting the aflatoxin-synthesizing genes to indicate the degree of risk a genotype has of being a phenotypic producer was demonstrated. In this study, 19 strains of the A. flavus group, including A. flavus, A. parasiticus, A. oryzae, A. sojae, and one Aspergillus niger, were subjected to PCR testing in an attempt to detect four genes, encoding for norsolorinic acid reductase (nor-1), versicolorin A dehydrogenase (ver-1), sterigmatocystin O-methyltransferase (omt-1), and a regulatory protein (apa-2), involved in aflatoxin biosynthesis. Concurrently, the strains were cultivated in yeast-malt (YM) broth for aflatoxin detection. Fifteen strains were shown to possess the four target DNA fragments. With regard to aflatoxigenicity, all seven aflatoxigenic strains possessed the four DNA fragments, and five strains bearing less than the four DNA fragments did not produce aflatoxin. When peanut kernels were artificially contaminated with A. parasiticus and A. niger for 7 days, the contaminant DNA was extractable from a piece of cotyledon (ca. 100 mg), and when subjected to multiplex PCR testing using the four pairs of primers coding for the above genes, they were successfully detected. The target DNA fragments were detected in the kernels infected with A. parasiticus, and none was detected in the sound (uninoculated) kernels or in the kernels infected with A. niger.
Collapse
Affiliation(s)
- Ruey-Shyang Chen
- Graduate Institute of Biotechnology, National Chiayi University, Taiwan
| | | | | | | |
Collapse
|
24
|
Rigó K, Varga J, Tóth B, Téren J, Mesterházy A, Kozakiewicz Z. Evolutionary relationships within Aspergillus section Flavi based on sequences of the intergenic transcribed spacer regions and the 5.8S rRNA gene. J GEN APPL MICROBIOL 2002; 48:9-16. [PMID: 12469311 DOI: 10.2323/jgam.48.9] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Sequences of the intergenic transcribed spacer regions and the 5.8S rRNA gene (455 nucleotides) of type strains or representative isolates of 23 species and subspecies either currently assigned to Aspergillus subgenus Circumdati section Flavi or other closely related sections, were analyzed. Parsimony analysis of sequence data indicated that species of Aspergillus section Flavi form distinct clades. The three main clades identified based on sequence data could also be distinguished based on colony color, and their ubiquinone systems. The 'A. flavus' clade includes species characterized with Q-10(H(2)) as their main ubiquinone, conidial colors in shades of green, and dark sclerotia. The 'A. tamarii' clade involves species with ubiquinone system Q-10(H(2)), and conidia in shades of olive to brown, while the 'A. alliaceus' clade consists of species with Q-10 ubiquinone system, and conidia in shades of ocher. The synnematous species A. coremiiformis was found to be closely related to species in the 'A. tamarii' clade. A. thomii and A. terricola var. americana were found to be related to the 'A. flavus' clade in spite of producing brownish colonies. Three species, A. nomius, A. avenaceus, and A. leporis were found to form separate lineages not closely related to any of the main clades identified. It is suggested that A. clavatoflavus and A. zonatus be excluded from Aspergillus section Flavi. Phylogenetic analysis of partial 26S rRNA gene sequences (564 nucleotides) supported our findings.
Collapse
Affiliation(s)
- Krisztina Rigó
- Department of Microbiology, Faculty of Sciences, University of Szeged, P.O. Box 533, H-6701 Szeged, Hungary
| | | | | | | | | | | |
Collapse
|
25
|
Wang L, Yokoyama K, Takahasi H, Kase N, Hanya Y, Yashiro K, Miyaji M, Nishimura K. Identification of species in Aspergillus section Flavi based on sequencing of the mitochondrial cytochrome b gene. Int J Food Microbiol 2001; 71:75-86. [PMID: 11764895 DOI: 10.1016/s0168-1605(01)00597-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The partial sequences of the mitochondrial (mt) cytochrome b gene (402 bp) were determined for species of Aspergillus section Flavi. On the basis of identities of DNA sequences, 77 strains were divided into seven DNA types, from D-1 to D-7. The type strains of A. sojae, A. parasiticus, A. flavus and A. oryzae together, A. tamarii, and A. nomius were placed in DNA types D-1. D-2, D-4, D-5 and D-7, respectively. These species could be differentiated from each other. Furthermore, two other DNA types, D-3 and D-6 were found. DNA type D-3 was closely related to A. parasiticus (D-2) and included one strain that deposited as A. flatus var. flavus and produced aflatoxins B and G. DNA types D-6 included one strain named A. flavus and closely related to A. tamarii. The observations of conidial wall texture by SEM (Scanning Electron Microscopy) supported the relationships derived from the cytochrome b gene. The production of aflatoxins was also examined. Using the DNA sequence of cytochrome b gene, several strains were reidentified. The derived amino acids sequences were all the same in the studied strains. The mt cytochrome b gene is useful and reliable in distinguishing and identifying the species in Aspergillus section Flavi.
Collapse
Affiliation(s)
- L Wang
- Research Center for Pathogenic Fungi and Microbial Toxicoses, Chiba University, Japan
| | | | | | | | | | | | | | | |
Collapse
|
26
|
Kumeda Y, Asao T. Heteroduplex panel analysis, a novel method for genetic identification of Aspergillus Section Flavi strains. Appl Environ Microbiol 2001; 67:4084-90. [PMID: 11526009 PMCID: PMC93133 DOI: 10.1128/aem.67.9.4084-4090.2001] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
For genetic identification of Aspergillus Section Flavi isolates and detection of intraspecific variation, we developed a novel method for heteroduplex panel analysis (HPA) utilizing fragments of the internal transcribed spacer (ITS) regions (ITS1-5.8S-ITS2) of the rRNA gene that was PCR amplified with universal primers. The method involves formation of heteroduplexes with a set of reference fragments amplified from Aspergillus flavus, A. parasiticus, A. tamarii, and A. nomius and subsequent minislab vinyl polymer gel electrophoresis. The test panel is compared with species-specific standard panels (F-1, P-1, T-1, and N-1) generated by pairwise reannealing among four reference fragments. Of 90 test panels, 89 succeeded in identifying the species and 74 were identical to one of the four standard panels. Of the 16 new panels, 11 A. flavus/A. oryzae panels were identical and typed as F-2 and 4 of 5 A. nomius panels were typed as N-2 or N-3. The other strain, A. nomius IMI 358749, was unable to identify the species because no single bands were formed with any of the four reference strains. DNA sequencing revealed that our HPA method has the highest sensitivity available and is able to detect as little as one nucleotide of diversity within the species. When Penicillium or non-Section Flavi Aspergillus was subjected to HPA, the resulting bands of heteroduplexes showed apparently lower mobility and poor heteroduplex formation. This indicates that HPA is a useful identification method without morphological observation and is suitable for rapid and inexpensive screening of large numbers of isolates. The HPA typing coincided with the taxonomy of Section Flavi and is therefore applicable as an alternative to the conventional methods (Samson, R. A., E. S. Hoekstra, J. C. Frisvad, and O. Filtenborg, p. 64-97, in Introduction to Food- and Airborne Fungi, 6th ed., 2000).
Collapse
Affiliation(s)
- Y Kumeda
- Osaka Prefectural Institute of Public Health, Nakamichi 1-3-69, Higashinari-ku, Osaka 537-0025, Japan
| | | |
Collapse
|
27
|
Molecular genotype analysis of natural toxigenic and nontoxigenic isolates of Aspergillus flavus and A. parasiticus. ACTA ACUST UNITED AC 1999. [DOI: 10.1017/s0953756299008710] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
28
|
Nikkuni S, Nakajima H, Hoshina SI, Ohno M, Suzuki C, Kashiwagi Y, Mori K. Evolutionary relationships among Aspergillus oryzae and related species based on the sequences of 18S rRNA genes and internal transcribed spacers. J GEN APPL MICROBIOL 1998; 44:225-230. [PMID: 12501432 DOI: 10.2323/jgam.44.225] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Sayuki Nikkuni
- National Food Research Institute, Ministry of Agriculture, Forestry and Fisheries, Tsukuba 305-8642, Japan
| | | | | | | | | | | | | |
Collapse
|
29
|
Multiplex Polymerase Chain Reaction for the Detection of Potential Aflatoxin and Sterigmatocystin Producing Fungi. Syst Appl Microbiol 1996. [DOI: 10.1016/s0723-2020(96)80067-1] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
30
|
Kumeda Y, Asao T. Single-strand conformation polymorphism analysis of PCR-amplified ribosomal DNA internal transcribed spacers to differentiate species of Aspergillus section Flavi. Appl Environ Microbiol 1996; 62:2947-52. [PMID: 8702288 PMCID: PMC168082 DOI: 10.1128/aem.62.8.2947-2952.1996] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
A novel genetic approach for classifying the species of Aspergillus Section Flavi is described here. This approach consists of PCR amplification of the 5.8S ribosomal DNA-intervening internal transcribed spacer regions (ITS I-5.8S-ITS II) with universal primers and of analysis of the PCR product by the principle of single-strand conformation polymorphism (SSCP). The approximately 570- to 590-bp PCR products were denatured and subjected to electrophoresis on a polyacrylamide gel supplemented with 20% formamide. The SSCP patterns of these species became more distinct by the addition of formamide to the gel and by visualization with ethidium bromide staining. A little interspecific length polymorphism among amplified ribosomal DNAs was enhanced to be detected by PCR-SSCP analysis. This analysis was capable of classifying 67 of the 68 Aspergillus Section Flavi strains tested into the following four groups, regardless of origin: A. flavus/A. oryzae, A. parasiticus/A. sojae, A. tamarii, and A. nomius. The results of restriction fragment length polymorphism analysis with PCR products of the ITS regions were consistent with those of PCR-SSCP analysis, except for A. nomius, which was not clearly differentiated from A. parasiticus/A. sojae. Nonradiolabelled PCR-SSCP analysis is inexpensive and practical to perform without special apparatus or skill and should assist in fungal morphological identification.
Collapse
Affiliation(s)
- Y Kumeda
- Osaka Prefectural Institute of Public Health, Japan
| | | |
Collapse
|