Biodiversity of species of Aspergillus section Fumigati in semi-desert soils in Argentina / Biodiversidad de especies de Aspergillus de la sección Fumigati en suelos semidesérticos de Argentina

The distribution of Aspergillus species in soil has been widely studied all over the world. The aim of this study was the phenotypic and genotypic characterization of species belonging to section Fumigati present in soils from two Argentinian semi-desert areas having different geological conditions. Altogether, 23 isolates belonging to Aspergillus section Fumigati were recovered and identified using a polyphasic approach including phenotypic and molecular identifications. Aspergillus fumigatus sensu stricto and Aspergillus fumigatiaffinis had the highest frequency, of occurrence while isolates closely related to Aspergillus udagawae and Aspergillus felis were rarely observed. A. fumigatiaffinis and isolates closer to A. udagawae were isolated for the first time from Argentinian soils and this is the first report on the occurrence of species belonging to the A. felis clade in South America. Recent scientific interests in biodiversity, as well as the increasing importance of aspergilli as causative agents of human and animal diseases increase the need to understand the diversity and occurrence of these fungi in nature.

La distribución de especies de Aspergillus en el suelo se ha estudiado ampliamente en todo el mundo. El objetivo de este trabajo fue caracterizar fenotípica y genotípicamente las especies pertenecientes a la sección Fumigati presentes en los suelos de dos zonas semidesérticas de Argentina con diferentes geologías. En total, 23 Aspergillus de la sección Fumigati fueron aislados e identificados utilizando un enfoque polifásico incluyendo identificaciones fenotípicas y moleculares. Aspergillus fumigatus sensu stricto y Aspergillus fumigatiaffinis aparecieron con mayor frecuencia, mientras que los aislamientos relacionados a Aspergillus udagawae y a Aspergillus felis se observaron raramente. Este es el primer informe de A. fumigatiaffinis y de aislamientos estrechamente relacionados a A. udagawae en suelos argentinos; también el primero sobre la ocurrencia de especies pertenecientes al clado A. felis en Sudamérica. El emergente interés científico en la biodiversidad, así como la creciente importancia de Aspergillus como agentes causales de enfermedades humanas y animales, aumentan la necesidad de conocer la diversidad y la ocurrencia de estos hongos en la naturaleza.

Biodiversity of species of Aspergillus section Fumigati in semi-desert soils in Argentina.

The distribution of Aspergillus species in soil has been widely studied all over the world. The aim of this study was the phenotypic and genotypic characterization of species Aspergillus belonging to section Fumigati present in soils from two Argentinian semi-desert areas having different geological conditions. Altogether, 23 isolates belonging to Aspergillus section Fumigati were recovered and identified using a polyphasic approach including phenotypic and molecular identifications. Aspergillus fumigatus sensu stricto and Aspergillus fumigatiaffinis had the highest frequency, of occurrence while isolates closely related to Aspergillus udagawae and Aspergillus felis were rarely observed. A. fumigatiaffinis and isolates closer to A. udagawae were isolated for the first time from Argentinian soils and this is the first report on the occurrence of species belonging to the A. felis clade in South America. Recent scientific interests in biodiversity, as well as the increasing importance of aspergilli as causative agents of human and animal diseases increase the need to understand the diversity and occurrence of these fungi in nature.

Keratitis caused by the recently described new species Aspergillus brasiliensis: two case reports.

INTRODUCTION: Human infections caused by Aspergillus brasiliensis have not yet been reported. We describe the first two known cases of fungal keratitis caused by Aspergillus brasiliensis. CASE PRESENTATIONS: A 49-year-old Indian Tamil woman agricultural worker came with pain and defective vision in the right eye for one month. Meanwhile, a 35-year-old Indian Tamil woman presented with a history of a corneal ulcer involving the left eye for 15 days. The fungal strains isolated from these two cases were originally suspected to belong to Aspergillus section Nigri based on macro- and micromorphological characteristics. Molecular identification revealed that both isolates represent A. brasiliensis. CONCLUSION: The two A. brasiliensis strains examined in this study were part of six keratitis isolates from Aspergillus section Nigri, suggesting that this recently described species may be responsible for a significant proportion of corneal infections caused by black Aspergilli. The presented cases also indicate that significant differences may occur between the severities of keratitis caused by individual isolates of A. brasiliensis.

Two novel aflatoxin-producing Aspergillus species from Argentinean peanuts.

Two novel species from Aspergillus section Flavi from different species of Arachis (peanuts) in Argentina are described as Aspergillus arachidicola sp. nov. and Aspergillus minisclerotigenes sp. nov. Their novel taxonomic status was determined using a polyphasic taxonomic approach with phenotypic (morphology and extrolite profiles) and molecular (beta-tubulin and calmodulin gene sequences) characters. A. minisclerotigenes resembles Aspergillus flavus and Aspergillus parvisclerotigenus in producing aflatoxins B(1) and B(2), cyclopiazonic acid, kojic acid and aspergillic acid, but in addition it produces aflatoxins G(1) and G(2), aflavarins, aflatrem, aflavinines, parasiticolides and paspaline. This species also includes several isolates previously assigned to A. flavus group II and three Australian soil isolates. A. arachidicola produces aflatoxins B(1), B(2), G(1) and G(2), kojic acid, chrysogine and parasiticolide, and some strains produce aspergillic acid. The type strain of A. arachidicola is CBS 117610(T) =IBT 25020(T) and that of A. minisclerotigenes is CBS 117635(T) =IBT 27196(T). The Mycobank accession numbers for Aspergillus minisclerotigenes sp. nov. and Aspergillus arachidicola sp. nov. are respectively MB 505188 and MB 505189 (http://www.mycobank.org).

Aspergillus brasiliensis sp. nov., a biseriate black Aspergillus species with world-wide distribution.

A novel species, Aspergillus brasiliensis sp. nov., is described within Aspergillus section Nigri. This species can be distinguished from other black aspergilli based on intergenic transcribed region, beta-tubulin and calmodulin gene sequences, by amplified fragment length polymorphism analysis and by extrolite profiles. A. brasiliensis isolates produced naphtho-gamma-pyrones, tensidol A and B and pyrophen in common with Aspergillus niger and Aspergillus tubingensis, but also several unique compounds, justifying their treatment as representing a separate species. None of the isolates were found to produce ochratoxin A, kotanins, funalenone or pyranonigrins. The novel species was most closely related to A. niger, and was isolated from soil from Brazil, Australia, USA and The Netherlands, and from grape berries from Portugal. The type strain of Aspergillus brasiliensis sp. nov. is CBS 101740(T) (=IMI 381727(T)=IBT 21946(T)).