Biology subjects

Gerrits van den Ende, B.

Publications and source records attributed to Gerrits van den Ende, B..

3 recordsLinked to original sources

bioRxiv2024

Aspergillus species in Iceland: species distribution and cyp51A mutation testing in a 7.5-year clinical isolate collection

Introduction.Among challenges in diagnosing and treating aspergillosis are Aspergillus species identification, which can inform therapeutic choices, and detection of antifungal resistance. Increasing rates of triazole resistance have been reported for the most common species, Aspergillus fumigatus. Methods.A collection of clinical Aspergillus isolates cultured during 2014-2021, previously identified morphologically, were tested with the AsperGenius qPCR-kit for identification of A. fumigatus and Aspergillus flavus and the presence of a cyp51A mutation encoding azole resistance (TR34/L98H and Y121F/T289A); other species were identified with calmodulin sequencing. Results.Identification of the 312 isolates (224 patients) tested revealed 19 species in nine Aspergillus sections. Rare or cryptic species were identified in 48 isolates (44 patients). Thirty-one isolates had been assigned an incorrect species name when initially cultured. The TR34/L98H and Y121F/T289A mutations were not found in any of the 202 A. fumigatus isolates tested. Discussion.In this first study on clinical Aspergillus isolates in Iceland the proportion of cryptic and rare species was on par with findings from other countries. In contrast, unlike other studies we did not find the most common azole resistance-related mutations in A. fumigatus, possibly due to the absence of significant environmental antifungal pressure in the local agriculture.

microbiology↗

bioRxiv2024

Fungal pathogens exposed - genomic and phenotypic insights into Candida auris and its relatives of the Candida haemulonii species complex

Candida auris showed the world the ability of fungi to rapidly emerge as an urgent threat to public health. Close relatives of the Candida haemulonii complex exhibit also a similar multi-drug resistant nature and are increasingly reported as nosocomial pathogens. Here, we analyze both complete genomes assemblies and extensive phenotypic data for the five C. auris clades and pathogenic and non-pathogenic species related to the C. haemulonii species complex. First, we resolved the phylogeny of the species complex. Next, comparing C. auris to its pathogenic and non-pathogenic relatives we identified a pathogenic potential for the whole C. haemulonii species complex by shared gene content and phenotypic traits linked to drug resistance and virulence. In vivo virulence assays using the Galleria mellonella fungal infection model show that C. auris strains are significantly more virulent than any of the sibling species in the C. haemulonii complex. Phenotypic analysis links the increased virulence of C. auris to a more stress resistant phenotype compared to its siblings.

microbiology↗

bioRxiv2022

Candida khanbhai sp. nov., a new clinically relevant yeast within the Candida haemulonii species complex

Invasive fungal infections caused by non-albicans Candida species are increasingly reported. Recent advances in diagnostic and molecular tools enabled better identification and detection of these emerging pathogenic yeasts. Several of these emerging species belong to the Candida haemulonii species complex, which attracted much attention due to the rapid global emergence of its multi-drug resistant member Candida auris. Here, we describe a new clinically relevant yeast isolated from geographically distinct regions, representing the proposed novel species Candida khanbhai, member of the C. haemulonii species complex. Moreover, several members of the C. haemulonii species complex were observed to be invalidly described, including Candida auris and Candida vulturna. Hence, the opportunity was taken to correct this here, formally validating the names of various yeast species.

microbiology↗