Sarah Ahmed

Dr. Sarah Ahmed

Radboud University Medical Center
orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 July 2014 in Fungal Diversity
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Michaela LacknerMichaela Lackner
Michaela Lackner
SHSybren Sijbrand de Hoog
Sybren Sijbrand de Hoog
LYLiyue Yang
Liyue Yang
LMLeandro Ferreira Moreno
Leandro Ferreira Moreno
Sarah AhmedSarah Ahmed
Sarah Ahmed
LLLivia Cristina Liporagi Lopes
Livia Cristina Liporagi Lopes
As a result of fundamental changes in the International Code of Nomenclature on the use of separate names for sexual and asexual stages of fungi, generic names of many groups should be reconsidered. Members of the ECMM/ISHAM working group on Pseudallescheria/Scedosporium infections herein advocate a novel nomenclature for genera and species in Pseudallescheria, Scedosporium and allied taxa. The generic names Parascedosporium, Lomentospora, Petriella, Petriellopsis, and Scedosporium are proposed for a lineage within Microascaceae with mostly Scedosporium anamorphs producing slimy, annellidic conidia. Considering that Scedosporium has priority over Pseudallescheria and that Scedosporium prolificans is phylogenetically distinct from the other Scedosporium species, some name changes are proposed. Pseudallescheria minutispora and Petriellidium desertorum are renamed as Scedosporium minutisporum and S. desertorum, respectively. Scedosporium prolificans is renamed as Lomentospora prolificans.

10 December 2014 in Persoonia - Molecular Phylogeny and Evolution of Fungi
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Journal Article
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Sarah AhmedSarah Ahmed
Sarah Ahmed
WSWendy Laureijssen-van de Sande
Wendy Laureijssen-van de Sande
DSD.A. Stevens
D.A. Stevens
Ahned FahalAhned Fahal
Ahned Fahal
ADA.D. van Diepeningen
A.D. van Diepeningen
GHG.S. de Hoog
G.S. de Hoog
Eumycetoma is a chronic fungal infection characterised by large subcutaneous masses and the presence of sinuses discharging coloured grains. The causative agents of black-grain eumycetoma mostly belong to the orders Sordariales and Pleosporales. The aim of the present study was to clarify the phylogeny and taxonomy of pleosporalean agents, viz. Madurella grisea, Medicopsis romeroi (syn.: Pyrenochaeta romeroi), Nigrograna mackinnonii (syn. Pyrenochaeta mackinnonii), Leptosphaeria senegalensis, L. tompkinsii, and Pseudochaetosphaeronema larense. A phylogenetic analysis based on five loci was performed: the Internal Transcribed Spacer (ITS), large (LSU) and small (SSU) subunit ribosomal RNA, the second largest RNA polymerase subunit (RPB2), and translation elongation factor 1-alpha (TEF1) gene. In addition, the morphological and physiological characteristics were determined. Three species were well-resolved at the family and genus level. Madurella grisea, L. senegalensis, and L. tompkinsii were found to belong to the family Trematospheriaceae and are reclassified as Trematosphaeria grisea comb. nov., Falciformispora senegalensis comb. nov., and F. tompkinsii comb. nov. Medicopsis romeroi and Pseudochaetosphaeronema larense were phylogenetically distant and both names are accepted. The genus Nigrograna is reduced to synonymy of Biatriospora and therefore N. mackinnonii is reclassified as B. mackinnonii comb. nov. Mycetoma agents in Pleosporales were phylogenetically quite diverse despite their morphological similarity in the formation of pycnidia, except for the ascosporulating genus Falciformispora (formerly in Leptosphaeria). Most of the species diagnosed from human mycetoma were found to be related to waterborne or marine fungi, suggesting an association of the virulence factors with oligotrophism or halotolerance.

23 May 2022 in Fungal Diversity
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HKHazal Kandemir
Hazal Kandemir
KDKarolina Dukik
Karolina Dukik
MTMarcus de Melo Teixeira
Marcus de Melo Teixeira
JSJ. Benjamin Stielow
J. Benjamin Stielow
FDFatima Zohra Delma
Fatima Zohra Delma
SHSybren Sijbrand de Hoog
Sybren Sijbrand de Hoog
The order Onygenales is classified in the class Eurotiomycetes of the subphylum Pezizomycotina . Families in this order have classically been isolated from soil and dung, and two lineages contain causative agents of superficial, cutaneous and systemic infections in mammals. The ecology and habitat choices of the species are driven mainly by the keratin and cellulose degradation abilities. The present study aimed to investigate whether the ecological trends of the members of Onygenales can be interpreted in an evolutionary sense, linking phylogenetic parameters with habitat preferences, to achieve polyphasic definitions of the main taxonomic groups. Evolutionary processes were estimated by multiple gene genealogies and divergence time analysis. Previously described families, namely, Arthrodermataceae , Ajellomycetaceae , Ascosphaeraceae , Eremascaceae , Gymnoascaceae , Onygenaceae and Spiromastigoidaceae, were accepted in Onygenales , and two new families, Malbrancheaceae and Neogymnomycetaceae, were introduced. A number of species could not be assigned to any of the defined families. Our study provides a revised overview of the main lines of taxonomy of Onygenales , supported by multilocus analyses of ITS, LSU, TUB , TEF1 , TEF3 , RPB1 , RPB2, and ribosomal protein 60S L10 (L1) ( RP60S ) sequences, combined with available data on ecology, physiology, morphology, and genomics.

21 November 2023 in Journal of Clinical Microbiology
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Journal Article
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SHSybren Sijbrand de Hoog
Sybren Sijbrand de Hoog
TWThomas J. Walsh
Thomas J. Walsh
Sarah AhmedSarah Ahmed
Sarah Ahmed
Ana Alastruey-IzquierdoAna Alastruey-Izquierdo
Ana Alastruey-Izquierdo
BABarbara D. Alexander
Barbara D. Alexander
SZSean Zhang
Sean Zhang
The rapid pace of name changes of medically important fungi is creating challenges for clinical laboratories and clinicians involved in patient care. We describe two sources of name change which have different drivers, at the species versus the genus level. Some suggestions are made here to reduce the number of name changes. We urge taxonomists to provide diagnostic markers of taxonomic novelties. Given the instability of phylogenetic trees due to variable taxon sampling, we advocate to maintain genera at the largest possible size. Reporting of identified species in complexes or series should where possible comprise both the name of the overarching species and that of the molecular sibling, often cryptic species. Because the use of different names for the same species will be unavoidable for many years to come, an open access online database of the names of all medically important fungi, with proper nomenclatural designation and synonymy, is essential. We further recommend that while taxonomic discovery continues, the adaptation of new name changes by clinical laboratories and clinicians be reviewed routinely by a standing committee for validation and stability over time, with reference to an open access database, wherein reasons for changes are listed in a transparent way.

9 September 2017 in Medical Mycology
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WSWendy Laureijssen-van de Sande
Wendy Laureijssen-van de Sande
AFAhmed Fahal
Ahmed Fahal
Sarah AhmedSarah Ahmed
Sarah Ahmed
JSJulian Alberto Serrano
Julian Alberto Serrano
ABAlexandro Bonifaz
Alexandro Bonifaz
OGon behalf of the eumycetoma working group
on behalf of the eumycetoma working group
On 28th May 2016, mycetoma was recognized as a neglected tropical disease by the World Health Organization. This was the result of a 4-year journey starting in February 2013 with a meeting of global mycetoma experts. Knowledge gaps were identified and included the incidence, prevalence, and mapping of mycetoma; the mode of transmission; the development of methods for early diagnosis; and better treatment. In this review, we review the road to recognition, the ISHAM working group meeting in Argentina, and we address the progress made in closing the knowledge gaps since 2013. Progress included adding another 9000 patients to the literature, which allowed us to update the prevalence map on mycetoma. Furthermore, based on molecular phylogeny, species names were corrected and four novel mycetoma causative agents were identified. By mapping mycetoma causative agents an association with Acacia trees was found. For early diagnosis, three different isothermal amplification techniques were developed, and novel antigens were discovered. To develop better treatment strategies for mycetoma patients, in vitro susceptibility tests for the coelomycete agents of black grain mycetoma were developed, and the first randomized clinical trial for eumycetoma started early 2017.

19 January 2018 in Scientific Reports
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AŠAdnan Šišić
Adnan Šišić
JBJelena Baćanović-Šišić
Jelena Baćanović-Šišić
AAAbdullah M. S. Al-Hatmi
Abdullah M. S. Al-Hatmi
Petr KarlovskyPetr Karlovsky
Petr Karlovsky
Sarah AhmedSarah Ahmed
Sarah Ahmed
MFMaria Finckh
Maria Finckh
The Fusarium solani species complex (FSSC) has been studied intensively but its association with legumes, particularly under European agro-climatic conditions, is still poorly understood. In the present study, we investigated phylogenetic relationships and aggressiveness of 79 isolates of the FSSC collected from pea, subterranean clover, white clover and winter vetch grown under diverse agro-climatic and soil conditions within Temperate and Mediterranean Europe. The isolates were characterized by sequencing tef1 and rpb2 loci and by greenhouse aggressiveness assays. The majority of the isolates belonged to two lineages: the F. pisi comb. nov. lineage (formerly F. solani f. sp. pisi) mainly accommodating German and Swiss isolates, and the Fusisporium (Fusarium) solani lineage accommodating mainly Italian isolates. Based on the results of aggressiveness tests on pea, most of the isolates were classified as weakly to moderately aggressive. In addition, using one model strain, 62 accessions of 10 legume genera were evaluated for their potential to host F. pisi, the species known mainly as a pathogen of pea. A total of 58 accessions were colonized, with 25 of these being asymptomatic hosts. These results suggest a broad host range for F. pisi and challenge the forma specialis naming system in Fusarium.