Infections@BDI Seminar - The phylogenetic host range of pathogens
Monday, 07 October 2019, 12pm to 1pm
Seminar room 0, BDI, Old Road Campus, OX3 7LF
Many major human pathogens are multi-host pathogens of other vertebrates. Describing the general patterns of host-pathogen associations can therefore help us to understand the risk factors for human disease emergence. I'll present findings from a manually compiled host-pathogen association database covering 2,595 bacterial and viral species infecting 2,656 vertebrate hosts, assembled from a comprehensive literature review. By also building a multi-mitochondrial gene tree for all host species, we can compute direct phylogenetic similarities between hosts and analyse the patterns of host range for vertebrate pathogens. While most pathogens in the database appear to be specialists infecting only a single host, several pathogen traits are significantly associated with greater host range: for viruses, having an RNA genome and a larger viral genome size; for bacteria, being motile and aerobic. Pathogens classed as zoonotic have a larger host range even when discounting their infection of humans. We find a strong relationship between the fraction of pathogens shared between host orders and the phylogenetic distance between them, supporting host phylogenetic similarity as the primary factor for host-switching.