Cargando…

Molecular Analysis of S-morphology Aflatoxin Producers From the United States Reveals Previously Unknown Diversity and Two New Taxa

Aflatoxins are highly toxic carcinogens that detrimentally influence profitability of agriculture and the health of humans and domestic animals. Several phylogenetically distinct fungi within Aspergillus section Flavi have S-morphology (average sclerotial size < 400 μm), and consistently produce...

Descripción completa

Detalles Bibliográficos
Autores principales: Singh, Pummi, Callicott, Kenneth A., Orbach, Marc J., Cotty, Peter J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7315800/
https://www.ncbi.nlm.nih.gov/pubmed/32625180
http://dx.doi.org/10.3389/fmicb.2020.01236
_version_ 1783550322163056640
author Singh, Pummi
Callicott, Kenneth A.
Orbach, Marc J.
Cotty, Peter J.
author_facet Singh, Pummi
Callicott, Kenneth A.
Orbach, Marc J.
Cotty, Peter J.
author_sort Singh, Pummi
collection PubMed
description Aflatoxins are highly toxic carcinogens that detrimentally influence profitability of agriculture and the health of humans and domestic animals. Several phylogenetically distinct fungi within Aspergillus section Flavi have S-morphology (average sclerotial size < 400 μm), and consistently produce high concentrations of aflatoxins in crops. S-morphology fungi have been implicated as important etiologic agents of aflatoxin contamination in the United States (US), but little is known about the diversity of these fungi. The current study characterized S-morphology fungi (n = 494) collected between 2002 and 2017, from soil and maize samples, in US regions where aflatoxin contamination is a perennial problem. Phylogenetic analyses based on sequences of the calmodulin (1.9 kb) and nitrate reductase (2.1 kb) genes resolved S-morphology isolates from the US into four distinct clades: (1) Aspergillus flavus S-morphotype (89.7%); (2) Aspergillus agricola sp. nov. (2.4%); (3) Aspergillus texensis (2.2%); and (4) Aspergillus toxicus sp. nov. (5.7%). All four S-morphology species produced high concentrations of aflatoxins in maize at 25, 30, and 35°C, but only the A. flavus S-morphotype produced unacceptable aflatoxin concentrations at 40°C. Genetic typing of A. flavus S isolates using 17 simple sequence repeat markers revealed high genetic diversity, with 202 haplotypes from 443 isolates. Knowledge of the occurrence of distinct species and haplotypes of S-morphology fungi that are highly aflatoxigenic under a range of environmental conditions may provide insights into the etiology, epidemiology, and management of aflatoxin contamination in North America.
format Online
Article
Text
id pubmed-7315800
institution National Center for Biotechnology Information
language English
publishDate 2020
publisher Frontiers Media S.A.
record_format MEDLINE/PubMed
spelling pubmed-73158002020-07-02 Molecular Analysis of S-morphology Aflatoxin Producers From the United States Reveals Previously Unknown Diversity and Two New Taxa Singh, Pummi Callicott, Kenneth A. Orbach, Marc J. Cotty, Peter J. Front Microbiol Microbiology Aflatoxins are highly toxic carcinogens that detrimentally influence profitability of agriculture and the health of humans and domestic animals. Several phylogenetically distinct fungi within Aspergillus section Flavi have S-morphology (average sclerotial size < 400 μm), and consistently produce high concentrations of aflatoxins in crops. S-morphology fungi have been implicated as important etiologic agents of aflatoxin contamination in the United States (US), but little is known about the diversity of these fungi. The current study characterized S-morphology fungi (n = 494) collected between 2002 and 2017, from soil and maize samples, in US regions where aflatoxin contamination is a perennial problem. Phylogenetic analyses based on sequences of the calmodulin (1.9 kb) and nitrate reductase (2.1 kb) genes resolved S-morphology isolates from the US into four distinct clades: (1) Aspergillus flavus S-morphotype (89.7%); (2) Aspergillus agricola sp. nov. (2.4%); (3) Aspergillus texensis (2.2%); and (4) Aspergillus toxicus sp. nov. (5.7%). All four S-morphology species produced high concentrations of aflatoxins in maize at 25, 30, and 35°C, but only the A. flavus S-morphotype produced unacceptable aflatoxin concentrations at 40°C. Genetic typing of A. flavus S isolates using 17 simple sequence repeat markers revealed high genetic diversity, with 202 haplotypes from 443 isolates. Knowledge of the occurrence of distinct species and haplotypes of S-morphology fungi that are highly aflatoxigenic under a range of environmental conditions may provide insights into the etiology, epidemiology, and management of aflatoxin contamination in North America. Frontiers Media S.A. 2020-06-11 /pmc/articles/PMC7315800/ /pubmed/32625180 http://dx.doi.org/10.3389/fmicb.2020.01236 Text en Copyright © 2020 Singh, Callicott, Orbach and Cotty. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Microbiology
Singh, Pummi
Callicott, Kenneth A.
Orbach, Marc J.
Cotty, Peter J.
Molecular Analysis of S-morphology Aflatoxin Producers From the United States Reveals Previously Unknown Diversity and Two New Taxa
title Molecular Analysis of S-morphology Aflatoxin Producers From the United States Reveals Previously Unknown Diversity and Two New Taxa
title_full Molecular Analysis of S-morphology Aflatoxin Producers From the United States Reveals Previously Unknown Diversity and Two New Taxa
title_fullStr Molecular Analysis of S-morphology Aflatoxin Producers From the United States Reveals Previously Unknown Diversity and Two New Taxa
title_full_unstemmed Molecular Analysis of S-morphology Aflatoxin Producers From the United States Reveals Previously Unknown Diversity and Two New Taxa
title_short Molecular Analysis of S-morphology Aflatoxin Producers From the United States Reveals Previously Unknown Diversity and Two New Taxa
title_sort molecular analysis of s-morphology aflatoxin producers from the united states reveals previously unknown diversity and two new taxa
topic Microbiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7315800/
https://www.ncbi.nlm.nih.gov/pubmed/32625180
http://dx.doi.org/10.3389/fmicb.2020.01236
work_keys_str_mv AT singhpummi molecularanalysisofsmorphologyaflatoxinproducersfromtheunitedstatesrevealspreviouslyunknowndiversityandtwonewtaxa
AT callicottkennetha molecularanalysisofsmorphologyaflatoxinproducersfromtheunitedstatesrevealspreviouslyunknowndiversityandtwonewtaxa
AT orbachmarcj molecularanalysisofsmorphologyaflatoxinproducersfromtheunitedstatesrevealspreviouslyunknowndiversityandtwonewtaxa
AT cottypeterj molecularanalysisofsmorphologyaflatoxinproducersfromtheunitedstatesrevealspreviouslyunknowndiversityandtwonewtaxa