1. Ranavirus but not Batrachochytrium dendrobatidis infections are elevated in invasive anurans compared to native island-dwelling anurans   
Brenda Rivera1, Dr. Kimberly Andrews2, Katrina Woods2 and Dr. Anna E. Savage1
Department of Biology1, University of Central Florida. Orlando, Florida
Applied Wildlife Conservation Lab2. Jekyll Island, Georgia.
The Southeastern US….and southeastern US
Introduction
Objective
Discussion
To determine the infection intensity, infection prevalence, and co-infection of Bd and Rv across
site, species, and season in Jekyll Island, GA
Although Bd prevalence has been known to increase in cooler, dryer months, no statistical significance was found between sampled months for Bd
Rv prevalence and infection intensity were higher in the cooler month of October compared to the wetter months of April, May, and June
There is a significant statistical difference in pathogen detection showing that body swabs have a better chance of detecting Bd and Rv than oral swabs
Co-infection in the island’s disease dynamics was indeterminant
Studies have found that the species sampled in this project have not been infected with Bd or Rv or have had very low infection prevalence, our results show that these four species are susceptible to infection from both pathogens in low quantities
Frog populations in Jekyll Island, GA are not at risk for population declines in the near future
Amphibian populations are declining due to the fungal pathogen Batrachochytrium dendrobatidis (Bd) which causes the disease chytridiomycosis, and the Iridiovirus Ranavirus (Rv)
Clinical signs of Bd infections are increased skin cells causing hyperkeratosis of the superficial skin
Rv will display liver necrosis, swelling, and erythema
Four taxonomically distinct frog species were sampled: two native treefrogs (Hyla cinerea (HyCi), Hyla squirella (HySq)), one native ranid frog (Lithobates sphenocephalus (LiSp)), and one invasive greenhouse frog (Eleutherodactylus planirostris (ElPl))
This is the first known study done on Bd and Rv in frogs in Jekyll Island, GA
Results
Bd and Rv prevalence maps Bd Rv
Implications
Monitoring infectious disease dynamics on islands is particularly important because introduced pathogens have the potential to rapidly wipe out the entire population. This work will help monitor and conserve island frog populations and can be applied to other locations where these species occur in order to prevent disease epidemics.
Figure 1: (Left) Mountain yellow-legged frog Bd infection die-off in the Sixty Lake basin area of the Sierra Nevada (Photo credit: Joel Sartore). (Right) Rv infection in an American bullfrog tadpole in Georgia, USA (Photo credit: Alan Cressler)
Figure 2: Maps showing Bd and Rv prevalence at the 24 sites sampled across Jekyll Island, GA. Circle size is relative to population size. Black proportions indicate pathogen detection and white proportions indicate no pathogen detection
Future Work
Species prevalence and intensity for Bd and Rv
Monthly prevalence and intensity for Bd and Rv
Future work will look at how precipitation and minimum, maximum, and mean temperature affect pathogen prevalence on the island. The life history of each species will also be analyzed to determine their effect on pathogen prevalence. Additional sampling in the future will also help determine whether Bd and Rv have spread throughout the island. *
Methods *
Oral and body swabs were collected by the Applied Wildlife Conservation Lab in Jekyll Island, GA
DNA was extracted from swabs using DNeasy Blood and Tissue kits (Qiagen)
All samples were tested for Bd individually through qPCR
All samples were tested for Rv using qPCR in pools of sites and species to determine pathogen presence. Pools that came out positive were then tested individually
Infection intensity, infection prevalence and pathogen co-occurrence were analyzed for Bd and Rv across site, species, and season
Prevalence maps were created in ArcGIS v to visualize positive samples found by site
Dot plots and ANOVA p-values were obtained using RStudio v * * * *
Figure 3: (A) Species Bd prevalence for oral and body swabs. (B) Species log transformed Bd mean intensity for oral and body swabs; HySq has a higher body Bd infection intensity than HyCi (p=2.7e-3), LiSp(p=7.9e-4), and ElPl (p=4.6e-3). (C) Species Rv prevalence for oral and body swabs; ElPl has a higher oral Rv prevalence than HyCi (p=1.7e-5), HySq (p=3.4e-2), and a higher body Rv infection intensity than LiSp (p=4.2e-3). (D) Species log transformed Rv mean intensity for oral and body swabs; ElPl has a higher oral Rv infection intensity than HyCi (p=1.2e-3), HySq (p=2.4e-2), and LiSp (p=3.1e-4), as well as a higher body Rv infection intensity than HyCi (p=6.0e-2), and LiSp (p=2.5e-2)
Figure 4: (A) Monthly Bd prevalence. (B) Monthly log transformed Bd mean intensity (B). (C) Monthly Rv prevalence; Oct14 has a higher Rv prevalence than Aug14 (p=1.1e-3), May14 (p=1.7e-5), July14 (p=1.9e-5), April15 (p=2.6e-4), and June15 (p=2.05e-5). (D) Monthly log transformed Rv intensity; Oct14 has a higher Rv prevalence than Aug14 (p=1.1e-3), May14 (p=1.7e-5), July14 (p=1.9e-5), and April15 (p=2.6e-4). Asterisks correspond to significant p-values.
Figure 5: Preparing a MasterMix for a qPCR
Acknowledgments
I would like to thank the Savage Lab for their support, most especially Ariel Horner for her help in training for DNA extraction and qPCR, and Taina Torres for her assistance in using ArcGIS. I would also like to thank UCF AAP Department for their financial support in this project.