Post on 06-Jul-2015
description
transcript
Ranavirus in Costa RicaJake Kerby, Ph.D. (@ecologyprof)
University of South Dakota
#RV13
Acknowledgements
Funding:
US Fish and Wildlife Service- Wildlife Without Borders
NSF- Major Research Instrumentation Grant
Rufford Grant
Authors:
Steven Whitfield, Erica Geerdes: USD
Dr. Adrian Pinto, Iria Chacon, Erick BallesteroRodriguez: Universidad de Costa Rica
Randall Jimenez: National Univ of Costa Rica
Mo Donnelly: Florida International University
Background
Amphibian decline story: Chytrid?
Central America hosts a diverse, unique, and highly threatened amphibian fauna, yet there has been little effort to describe presence, systematics, host range, or impacts to hosts or populations of impacts to hosts or populations of Ranaviruses.
One paper of interest- Whitfield declines in both reptiles and amphibians
Sought out to examine disease presence in both
Whitfield S M et al. PNAS 2007;104:8352-8356
Amphibian disease
The story of chytrid in Costa Rica is well documented,
but what about Ranavirus?
One study done by Angela Picco did not find evidence
of infection (Picco and Collins 2007).
Rick Speare mentions a “possible iridovirus” in Cane Rick Speare mentions a “possible iridovirus” in Cane
toads in 1991.
Might Ranavirus be present?
Initial surveys
Did initial work on 12 species with sampling only at La
Selva Biological Field Station. Found ranavirus present
in four individuals of the species, Craugastor bransfordii.
Published in Herpetological Review (Whitfield et al. Published in Herpetological Review (Whitfield et al.
2012).
Co-infection
We did a more thorough study expanding the surveys to 20 species at the same site. We examined species for infections of both ranavirus and Bd.
Found several species were co-infected. (Whitfield et al. 2013). First to document (Whitfield et al. 2013). First to document association of ranavirus and Bd infection in a single species: Craugastor fitzingeri.
Overall, 42 individuals from 9 species were found with ranavirus. (16.6%)
No clinical signs of disease though.
Where is it from?
One key question is to better understand where this
ranavirus strain emerged from.
We sequenced the initial strain and found it to match a
North American isolate.
Was it introduced from N. America? How? When?Was it introduced from N. America? How? When?
Unintuitive trade
Shops in Costa Rica illegally sell
Xenopus laevis smuggled in from the
states.
We obtained animals that were We obtained animals that were
confiscated at the Costa Rica airport
and found them to be infected with
ranavirus!
Still need to sequence DNA from these
samples.
Unintuitive trade
Other trade species: Newts,
Fire bellied toads…
Given previous work in US
on bait trade influence of on bait trade influence of
infection, this might be a
serious but overlooked
problem.
More work desperately
needed.
Current work
We are currently working to isolate a Costa Rican
strain of ranavirus from wild populations, from pet
trade, and from introduced populations of Puerto
Rican Coquis.
Examining presence of ranavirus in same populations
and in museum samples dating back to 70s.
Would like to better understand if the pathogen is
responsible for amphibian declines in the country.
Relict Sites
Expanded the search to across the country
Currently are analyzing samples from 10 sites that have
persisted through previous die offs. Examining both
RV and Bd.RV and Bd.
Other Ranavirus work
Currently, I have a PhD student examining Ranavirus infection in South Dakota/Nebraska
Drew detected an outbreak in Spea
bombifrans. Currently being isolated bombifrans. Currently being isolated in Jesse Brunner’s laboratory.
We just received funding to examine the impacts of agricultural inputs on salamanders in South Dakota.
@drewrdavis- follow for latest updates!
Questions?