Aspergillus viridinutans complex: polyphasic taxonomy, mating behaviour and antifungal susceptibility testing

Ref ID: 19438

Author:

Z. Dudová ,1 V. Hubka,2 L. Svobodov a,3 P. Hamal,3 A. Nov akov a,4
T. Matsuzawa,5 T. Yaguchi,5 A. Kub atov a2 and M. Kolar305;k6

Author address:

1Faculty of Science, Charles University in Prague, Czech Republic;
2Charles University in Prague, Faculty of Science, Department of
Botany, Prague, Czech Republic; 3Palacky University, Faculty of
Medicine and Dentistry, Dept. of Microbiology, Olom

Full conference title:

6th Trends in Medical Mycology 2013

Date: 11 October 2014

Abstract:

The aim of this study was to determine the species boundaries within
the Aspergillus viridinutans complex. The species belonging to this
complex are predominantly soil-inhabiting organisms that are
increasingly reported as opportunistic human and animal pathogens.
The species show considerable phenotypic variability but typically
share nodding heads (some vesicles borne at an angle to the stipe)
and relatively poorly sporulating colonies with abundant aerial
mycelium (in comparison with A. fumigatus s. str.). A total number of 72 isolates from various substrates and countries was subjected to
morphological, physiological and molecular analysis (RPB2, calmod-
ulin, beta-tubulin and actin gene). In addition, the mating experi-
ments were provided within and between isolates representing
opposite mating types from all major clades (on different media and
temperatures). The physiological data (maximum growth tempera-
ture, acid production on CREA and Ehrlich test) and morphology of
the anamorphic state was taxonomically insignificant due to overlap-
ping features. Phylogenetic analysis based on combined dataset and
mating experiments data showed that A. viridinutans complex com-
prises at least five to six heterothallic species and two homothallic
species. Fertile ascomata were observed in three heterothallic species.
These species differed in morphology of ascospores (width of crests
and convex surface ornamentation) and conditions suitable for teleo-
morph induction. Only A. udagawae, A. felis and one tentative new
species represent clinically relevant species. Our four locus typing
scheme was able to unambiguously distinguish almost all isolates
tested (Simpson!s index close to 1). The calmodulin gene had the
highest discriminatory power. Antifungal susceptibility testing (Yea-
stOne panels) showed that posaconazole was the most active antifun-
gal agent across species. All species were resistant to 5-fluorocytosine
and fluconazole, other antifungals showed species-specific susceptibil-
ity patterns. This work was supported by the project GAUK 607812
and by the Internal Grant Agency of the Palack y University Olo-
mouc, Czech Republic (grant no. LF_2013_012).

Abstract Number: p371

Conference Year: 2013

Link to conference website: NULL

New link: NULL

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