Nematodes (microscopic roundworms) are key in maintaining soil biodiversity and health, but some species can also infect and damage agricultural crops. In soil nematodes encounter natural parasites, such as bacteria, microsporidia and viruses, that infect and sicken them. My research focuses on the interactions between hosts (mainly nematodes) and their parasites and experiments range from laboratory to field studies. My current research topics are summarized below.
Nematode biodiversity and parasite presence – Species biodiversity can shape parasite presence in different systems of macroscopic species, however if this is also true for (soil) microorganisms is unknown. I am currently testing this so-called ‘dilution theory of disease’ in bacterivorous nematode communities. I extract bacterivorous nematode communities together with their parasites from natural habitats. Communities are then screened morphologically and by long-read amplicon sequencing and species information is linked to parasite observations. In case nematode biodiversity determines parasite presence, this has broad implications ranging from fundamental understanding of soil ecosystems to application of biocontrol parasites in agriculture.
Natural variation in parasite susceptibility - Genetic variations within the same species determine susceptibility to natural parasites. I use the model nematode Caenorhabditis elegans and its naturally occurring parasite the Orsay virus to understand how within-species variation changes parasite susceptibility. To this end, I employ the extensive genetic, molecular and microscopic tools available for this model system.
Nematodes disperse soil parasites (collaborative research with the NIOO-KNAW) – Bacterivorous nematodes feed on bacteria. At the same time, these bacteria-feeding nematodes disperse their bacterial food source, thus enhancing bacterial spread through soil. However, if nematodes moving through soil also spread a key parasite of bacteria, bacteriophages, is undetermined. In case nematodes spread bacteriophages, this explains how immobile bacteriophages can spread through soil. Because bacteriophages drive key soil processes, this illustrates how complex biological interactions can be critical in soil health.
Characteristics and application of persistently infecting narnaviruses (research performed at the Laboratory of Virology) – Narnaviruses persistently infect many invertebrate species, including nematodes and mosquitos. Mosquitos also vector many other viruses, including human-infecting viruses such as Zika virus and West-Nile virus. I investigate biology of narnaviruses and potential of using a modified narnavirus as a vaccine protecting mosquitos from co-infection with human-infecting viruses.