The community ecology of viral pathogens - Causes and consequences of coinfection in hosts and vectors.


Research Objectives

Our objectives are to answer four questions:

  • By what mechanisms do pathogen species interact?
  • What are the ecological and dynamical consequences of interactions among pathogen species?
  • Which components of multi-pathogen systems (vectors, pathogens, hosts, and abiotic conditions) control their dynamics?
  • How does space shape the dynamics of multi-pathogen systems?

Study Species

  • Barley yellow dwarf virus-PAV (BYDV-PAV)
  • Barley yellow dwarf virus-MAV (BYDV-MAV)
  • Barley yellow dwarf virus-SGV (BYDV-SGV)
  • Barley yellow dwarf virus-RMV (BYDV-RMV)
  • Cereal yellow dwarf virus-RPV (CYDV-RPV)
  • Rhopalosiphum padi (L.) (the bird cherry-oat aphid)
  • Rhopalosiphum maidis (Fitch) (the corn leaf aphid)
  • Schizaphis graminum (Rondani) (the greenbug)
  • Sitobion avenae (Fabricius) (the English grain aphid)
  • Sitobion fragariae (Walker) (the blackberry-cereal aphid)
  • Metopolophium dirhodum (Walker) (the rose-grain aphid)
  • Bromus hordeaceus L. (soft brome)
  • Elymus glaucus Buckley (blue wildrye)

Collaborators


 

Many individual host organisms, including humans, are simultaneously coinfected by multiple pathogen species. The diversity (number and identity) of coinfecting pathogens can modulate both pathogen transmission among hosts and pathogen impacts on hosts. Nonetheless, little is known about the processes that govern pathogen diversity. This research will integrate field experiments and mathematical models to study the causes and consequences of pathogen diversity. The study develops a model system using five viral pathogens of grasses (the cereal and barley yellow dwarf viruses). These viruses provide an experimentally tractable model for vector-transmitted generalist pathogens, the dominant type of emerging pathogen of humans, crops, and other species. This approach will allow the investigation of the interacting roles of the pathogen species themselves, the insect vectors (aphids) that transmit them, their plant hosts, climate conditions, and spatial processes in controlling the dynamics of systems that include multiple pathogen species. Further, it will elucidate the mechanisms by which pathogens interact, and evaluate the consequences of these interactions for pathogen transmission and host fitness. The work will advance the understanding multi-pathogen dynamics - a key step towards developing a comprehensive understanding of the ecology of infectious disease. This project is based at the University of California’s Hopland Research and Extension Center. It is funded by the NSF Ecology of Infectious Disease program through 2016.


(Top) Hopland Research and Extension Center, CA.

(Center) Sitobion fragariae .

(Bottom) Hopland Research and Extension Center, CA.