Teun Boekhout

Teun Boekhout is head of the yeast research department. He is also member of the KNVM but also of IUMS, ISHAM and ECCMID.

He also teaches regularly in courses given by CBS-KNAW and various Dutch research schools. Besides, he supervised many trainees (MLO, HLO, B.Sc., M.Sc.) and several Ph.D. students) and act regularly as a referent and examiner in M.Sc. and Ph.D. examinations in The Netherlands and abroad

Within Mycology his main research focuses on the functional diversity of pathogenic yeasts, especially the Cryptococcus neoformans (Cn) species complex and Malassezia spp. Extensive national and international research collaborations exist in these fields. Development of rapid and reliable diagnostics tools is an important topic. With Bruker Daltonic Gmbh (Bremen, Germany) his group collaborates on the development of MALDI-TOF mass spectroscopy for the identification of yeasts and filamentous fungi. Host-pathogen interactions are studied together with immunologists and biochemists in Amsterdam university and Utrecht university. Besides Teun Boekhout also works in yeast taxonomy, functional ecology, comparative genomics.

Expertise:

Yeasts, pathogens, Basidiomycetes, Cryptococcus, Malassezia, Candida, biodiversity, phylogenomics, ultrastructure, septa, bioprospecting, biosecurity, taxonomy, mushrooms, ecology, virulence, evolution, molecular detection

Projects:

- Understanding yeast biodiversity and evolution

In this research we aim to unify the phylogeny and taxonomy of all yeasts within the the Fungal Tree of Life (TOL) concept. One of the main achievements is to publish a new on-line version of the standard reference work 'The Yeasts, a Taxonomic Study' [5th edition, 2011, 1532 cites Google Scholar Jan. 29 2014]. With colleagues from State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China, a multigene phylogenetic analysis was performed of all currently accepted basidiomycetous yeast species (BYe-TOL project). This resulted in the recognition of two new classes, Monillielomycetes and Malasseziomycetes, in Ustilaginomycotina. Also in the Pucciniomycotina and Agaricomycotina major changes in the phylogenetic relationships and, consequently, their taxonomy will result from our work. In the context of the KNAW-supported barcoding project of the CBS collection (collaboration with Dr. Benjamin Stielow and Dr. Marizeth Groenewald, curator of the CBS yeast collection) a multigene-based phylogeny of all ascomycetous yeasts is being conducted. Although, still ongoing, we foresee a major impact on our understanding of the phylogenetic relationships among these yeasts, yeast-like taxa and other fungi. One of the main results will be a completely revised taxonomy of yeasts and for this we will organize a ‘New Yeast Taxonomy’ workshop in spring 2015.

- Mechanism of pathogenicity

In this research we focus mainly on pathogenic basidiomycetous yeasts, such as the Cryptococcus neoformans/Cr. gattii species complex and skin inhabiting Malassezia spp. C. neoformans is one of the major fungal pathogens causing over a million new infections per year with approximately 600,000 casualties. C. gattii, a sibling species, is of emerging importance as it infects immunocompetent humans and animals and is causing some major ongoing outbreaks. Moreover, the species is also emerging in Europe. Malassezia yeasts are skin commensals of humans and animals and a major component of the human skin microbiome. These yeasts are involved in a number of skin diseases, such as pityriasis versicolor, seborrheic dermatitits, atopic dermatitis etc., but also can cause sepsis, especially in neonates that receive parenteral nutrition. Our research projects aim to understand the relationship between pathogen biodiversity and virulence related properties of these clinically important species. In-depth studies focus on the relationship between evolution (incl. biodiversity, phylogeography, speciation, taxonomy) and pathogen traits (i.e. virulence, interaction with immune cells and susceptibility to antifungals) using a comparative genomics approach and phenotypic studies of the immune interactions.

- Innovative diagnostics

In the context of a multinational medical mycological oriented research program, we aim to develop innovative diagnostic tools for clinicians. The project brings together the expertise on Comparative Genomics (CRG – Barcelona, Spain), extensive Culture Validation (CBS, Utrecht, The Netherlands) and testing in a clinical set-up (Hamad Medical Corporation, Doha, Qatar). The idea behind this project, mainly funded by the Qatar National Research Foundation, is to design a bio-infomatics pipeline able to find marker genes for the identification of fungal pathogenic species – or groups of them. This is possible due to the intensive usage of completely sequenced genomes. Prioritized list of markers are then extensively validated using cultures to test the suitability of such markers in an experimental context. In the following stage, clinical evaluation will determine the success of our probes. With a rising number of publicly available complete fungal genomes, the selection of marker genes may get more and more accurate.

- Fungal biodiversity and ecology

Many fungal species still remain to be discovered. In ecologically focused projects that are usually done in collaborations we contribute to this species discovery as well as to understand their ecological roles. One such project focus on the diversity of ectomycorrhizal fungi in Dipterocarp forests in the Colombian Amazon using culturing and metagenomics approaches. In another project the diversity of marine microbes around Qatar is assessed by similar methods, and include pro- and eukaryotic microorganisms. Besides GIS mapping, analysis of ecological important parameters will be done by partners from Qatar and the [oil] industry.