Marie Therese Eckstein     email
Research Center for Infectious Diseases

Dr. Christian Pérez (Würzburg)
Promotion Committee:
Dr. Christian Pérez (Würzburg)
Dr. Martin Fraunholz (Würzburg)
Prof. Dr. Julia-Stefanie Frick (Universität Tübingen)
Prof. Dr. Joachim Morschhäuser (Würzburg)

Investigating the interplay between bacterial and fungal members of the human gut microbiota

The human gut microbiota inhabits microbes of all three domains of life - eukaryotes, archaea and bacteria – the microbiota plays a key role in human health and disease. However, little is known about the biology of non-bacterial members of the microbiota and even less about how they interact with cohabiting microbes and the host to shape the multiple functions ascribed to this microbial community. To get insights into these interactions, I am investigating two prominent members of the human digestive tract, the fungus Candida albicans and the bacterium Bacteroides thetaiotaomicron. It has been shown that these species can physically interact when cultured in vitro. To identify bacterial factors of B. thetaiotaomicron that are needed for the in vivo fitness of the bacterium in the presence of the fungus C. albicans, I have generated a transposon mutant library in this bacterial species. This library will be used to carry out genetic screens in a gnotobiotic mouse model of gastrointestinal colonization. Furthermore, I am characterizing the patterns of proliferation and spatial distribution of these two species in the intestine of gnotobiotic animals after mono- and co-colonization. I expect that these approaches will reveal genetic circuits and cellular functions involved in specific fungal-bacterial interactions that take place in the mammalian digestive tract.