24 November 2021, 16:00 CET - - Uncovering the determinants of pathogen diversity in nature

Anne-Liisa Laine

Professor of Ecology, University of Zürich, Switzerland, https://lainelab.net/

Pathogens are prevalent across all ecosystems and exert negative effects on their hosts. Hence, there is a pressing need to understand risks of infection and how these evolve. Traditionally, host-pathogen interactions have been largely viewed within the ‘one host-one parasite’ framework although in reality the same host may be attacked by a myriad of pathogenic microbes. However, remarkably little is known about the factors that determine which pathogens co-occur within the same host individual and how they interact. Theoretically the resulting interaction has been proposed to range along a continuum where at the one end we find superinfection with a single strain gaining dominance of the entire host, and at the other end of the continuum we find coinfection. The relative roles of pathogen-pathogen interactions, host attributes and the environment have been notoriously difficult to tease apart, and hence, the empirical study of disease dynamics under coinfection has lagged behind theoretical predictions. In my talk I will present case studies of within host pathogen strain diversity and species diversity, and what we’ve learned about the determinants of this diversity.