10.5061/DRYAD.P7507
Penczykowski, Rachel M.
Georgia Institute of Technology
Lemanski, Brian C. P.
Georgia Institute of Technology
Colgate University
Sieg, Robert Drew
Georgia Institute of Technology
Hall, Spencer R.
Indiana University Bloomington
Housley Ochs, Jessica
Georgia Institute of Technology
Kubanek, Julia
Georgia Institute of Technology
Duffy, Meghan A.
Georgia Institute of Technology
Data from: Poor resource quality lowers transmission potential by changing
foraging behaviour
Dryad
dataset
2014
Microcystis aeruginosa
Daphnia dentifera
food quality
feeding rate
Ankistrodesmus falcatus
parasite production
transmission rate
2014-12-04T00:00:00Z
2014-12-04T00:00:00Z
en
https://doi.org/10.1111/1365-2435.12238
35030 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
Resource quality can have conflicting effects on the spread of disease.
High quality resources could hinder disease spread by promoting host
immune function. Alternatively, high quality food might enhance the spread
of disease through other traits of hosts or parasites. Thus, to assess how
resource quality shapes epidemics, we need to delineate mechanisms by
which food quality affects key epidemiological traits. Here, we
disentangle effects of food quality on ‘transmission potential’ – a key
component of parasite fitness that combines transmission rate and parasite
production – using a zooplankton host and fungal parasite. We estimated
the components of transmission potential (i.e., parasite encounter rate,
susceptibility, and yield of parasite propagules) for hosts fed a high
quality green alga and a low quality cyanobacterium. A focal experiment
was designed to disentangle food quality effects on various components of
transmission potential. The low quality resource decreased transmission
potential by stunting host growth and altering foraging behaviour. Hosts
reared on low quality food were smaller and had lower size-corrected
feeding rates. Due to their slower grazing, they encountered fewer
parasite spores in the water. Smaller hosts also had lower risk of an
ingested spore causing infection (i.e., lower susceptibility), and yielded
fewer parasite propagules. Hosts switched from high to low quality food
during spore exposure also had low transmission potential – despite their
large size – because the poor quality resource strongly depressed
foraging. A follow-up experiment investigated traits of the low quality
resource that might have driven those results. Cyanobacterial compounds
that can inhibit digestive proteases of a related grazer likely did not
cause the observed reductions in transmission potential. Our study
highlights the value of using mechanistic models to pinpoint how resource
quality can change transmission potential. Overall, our results show that
low quality resources could inhibit the spread of disease through effects
on multiple components of transmission potential. They also provide
insight into how disease outbreaks in wildlife may respond to shifts in
resource quality caused by eutrophication or climate change.
Data from the infection assay and feeding rate assay in the first
experiment.The transmission model (equ. S1 and S2) and foraging model
(equ. S4) were simultaneously fit to these data from the infection and
feeding rate assays, respectively. For more details on how these data were
used to estimate components of transmission potential, see
'Statistical methods for estimating parameters' in Appendix
S1.First_Experiment.xlsxData from the infection assay in the second
experiment.The transmission model (equ. S1 and S2) was fit to these data
to estimate infection risk. For more details on how these data were used
to estimate components of transmission potential, see 'Statistical
methods for estimating parameters' in Appendix
S1.Second_Experiment.xlsx