One health consequences of circularity

Background

A. fumigatus is a fungus that grows on decaying plant material. It thrives particularly well on agricultural compost in which it produces large amounts of spores that spread very effectively through the air. Consequently, humans inhale these spores on a daily basis. This does not pose a risk to healthy persons, but the fungus is an opportunistic human pathogen: It can cause serious lung infections in patients with a weakened immune system (e.g. due to immunosuppressive therapy, COVID19 or influenza). The available fungicides used to combat Aspergillus infections (medicinal azoles) are similar to those used in agriculture and industry. The effectiveness of medicinal azoles is diminishing, as increasingly A. fumigatus strains are found that are resistant to these agents.Approach

The left panel shows the natural environment of Aspergillus fumigatus, the right panel shows a hotspot environment that can be the source and a reservoir for azole resistant A. fumigatus. Our research addresses how these hotspots can be changed into cold spots by altering the environment to minimize growth and dispersal of fumigatus and looks into ways of waste treatment that eliminate A. fumigatus spores. To do this, we study the genetics of adaptation, effect of (environmental) selection and link this to clinical practice. We use field sampling, laboratory experiments, whole genome sequencing and citizen science.

In a project funded under NWO-Groen III we address the One-Health consequences of circularity through the resistance development to environmental and medical azoles in the fungus Aspergillus fumigatus in accumulated organic residues.

Objectives

• use the diversity of organic waste disposal in the bulb-sector to discern the key factors driving resistance development,
• use these factors to draw up an intervention plan that will be tested in the laboratory and on-site
• extend the obtained knowledge to general organic waste disposal to assess resistance and health risk throughout the system.

For each of the objectives and during the whole programme, patient-risk will be monitored via local, regional, and national spore-trapping. Our project will deliver a quantitative and qualitative one-health risk-assessment for the pressing problem of rapidly spreading azole-resistance that will provide valuable lessons and actions to be taken to prevent similar problems arising in other parts of circular agriculture. The results from our programme can thus be instrumental in designing health-risk free circular systems.

Student opportunities

Students are very welcome to do MSc/BSc thesis work in the context of this project. This thesis work may connect to any of the topics above and/or on:

• Abundance of A. fumigatus spores in air and soil samples from the natural (filed/forest), agricultural (field/waste) or human (garden/indoor) environment throughout the year.
• Level and molecular characteristics of azole resistance in these A. fumigatus isolates
• Fungal life-cycle and genetics of adaptation
• Evolutionary questions on adaptation to local environments and trade-offs