Determinants of Host Species Jumps

An increasing number of disease epidemics have been linked to pathogen host species jumps. Although pathogens often infect closely related species, there are also many cases in which the original and new hosts are taxonomically diverse. Second, pathogens (even closely related ones) vary considerably in their host ranges, with some being specialists that only infect a single species and others capable of infecting hosts from a number of different taxonomic groups.

Few studies have broadly examined the overall prevalence of host jumps amongst pathogen groups, or the underlying genetic determinants enabling host-switching. We aim to fill this gap using both comparative and experimental approaches.

A) The influence of host range and taxonomy on bacterial pathogen emergence

We have been conducting a comprehensive literature review of ~ 700 bacterial pathogens of humans and animals to quantify whether host taxonomic relatedness and breadth of host range are important factors underlying the potential for pathogen host switching and emerging epidemics.

B) Experimental evolution of ranavirus to characterize the genetic basis of cross species viral infections

We have been working to establish a novel experimental evolution system using ranavirus, a wildlife pathogen capable of exploiting an unusually diverse range of hosts encompassing amphibian, reptile and fish species. Using this system, we aim to characterize the patterns of evolutionary change in different ranavirus strains as they adapt to different host cell cultures derived from species spanning the breadth of the virus' host range.