Giardia- a eukaryotic model pathobiont.

Microbial communities (microbiomes) in the gut are essential parts of the human body, affecting the overall physiology at many different levels.

Bacteria have been the main focus of studies of intestinal microbiomes but eukaryotic microbes are also members of the microbiomes, creating the eukaryome.

Recent data suggest that certain parasitic infections like Giardia can have beneficial effects and eukaryotic commensals can cause disease under certain conditions. These types of microbes have been named pathobionts.

Thus, the relationships in the microbiota are complex and we need to learn more about the molecular mechanisms behind disease-induction and asymptomatic colonization by intestinal protozoa in order to fully understand our microbiomes.

In this proposal, we focus on the intestinal protozoan parasite G. intestinalis that causes 180 million symptomatic diarrhea cases (giardiasis) yearly. Giardia causes little inflammation during infections and the microbiome is an important factor in pathogenesis. Drug resistance is an emerging problem, causing treatment problems.

Asymptomatic infections are common, more than 0.5 billion humans are colonized by Giardia.

New in vitro and in vivo infection models have been established and also genetic tools, making Giardia a unique eukaryotic model pathobiont.

We will characterize:- Giardia’s interaction with the intestinal epithelium and microbiota- Giardia’s anti-inflammatory properties- Metronidazole resistance in Giardia