Matthew J. Gray's research while affiliated with The University of Tennessee Medical Center at Knoxville and other places

Publications (116)

Article
Batrachochytrium salamandrivorans is an emerging fungus that is causing salamander declines in Europe. We evaluated whether an invasive frog species (Cuban treefrog, Osteopilus septentrionalis) that is found in international trade could be an asymptomatic carrier when exposed to zoospore doses known to infect salamanders. We discovered that Cuban t...
Article
Full-text available
Ranaviruses are emerging pathogens of poikilothermic vertebrates. In 2015 the Global Ranavirus Reporting System (GRRS) was established as a centralized, open access, online database for reports of the presence (and absence) of ranavirus around the globe. The GRRS has multiple data layers (e.g., location, date, host(s) species, and methods of detect...
Article
Full-text available
We provide a practical approach for decisions of when to apply standard vs. enhanced field biosecurity actions to forestall human-mediated translocation of amphibian and reptile disease-causing pathogens.
Article
An understanding of habitat selection and patterns of use by American black ducks (Anas rubripes; hereafter black ducks) during winter is important ecologically and for conservation of this declining species in the mid‐continent population of its North American range. During winters 2010–2011 and 2011–2012, we obtained 3,816 locations of 111 radiom...
Article
Full-text available
Environmental temperature is a key factor driving various biological processes, including immune defenses and host-pathogen interactions. Here, we evaluated the effects of environmental temperature on the pathogenicity of the emerging fungal pathogen, Batrachochytrium salamandrivorans ( Bsal ), using controlled laboratory experiments, and measured...
Article
Populations of the eastern hellbender Cryptobranchus alleganiensis alleganiensis have been declining for decades, and emerging pathogens and pesticides are hypothesized to be contributing factors. However, few empirical studies have attempted to test the potential effects of these factors on hellbenders. We simultaneously exposed subadult hellbende...
Article
Full-text available
Transmission is the fundamental process whereby pathogens infect their hosts and spread through populations, and can be characterized using mathematical functions. The functional form of transmission for emerging pathogens can determine pathogen impacts on host populations and can inform the efficacy of disease management strategies. By directly me...
Article
Resistance and tolerance are unique host defense strategies that can limit the impacts of a pathogen on a host. However, for most wildlife‐pathogen systems there are still fundamental uncertainties regarding 1) how changes in resistance and tolerance can affect disease outcomes and 2) the mechanisms underlying resistance and tolerance in host popul...
Chapter
Epidemic dynamics of infectious diseases with multiple routes of transmission are complex. Mathematical models can be used to determine invasion potential and identify which transmission pathway is dominant and can ultimately help identify appropriate intervention strategies. We developed compartmental host–pathogen models to examine the transmissi...
Article
Full-text available
Controlled experiments are one approach to understanding the pathogenicity of etiologic agents to susceptible hosts. The recently discovered fungal pathogen, Batrachochytrium salamandrivorans (Bsal), has resulted in a surge of experimental investigations because of its potential to impact global salamander biodiversity. However, variation in experi...
Article
Full-text available
Discovered in 2013, the chytrid fungus Batrachochytrium salamandrivorans (Bsal) is an emerging amphibian pathogen that causes ulcerative skin lesions and multifocal erosion. A closely related pathogen, B. dendrobatidis (Bd), has devastated amphibian populations worldwide, suggesting that Bsal poses a significant threat to global salamander biodiver...
Preprint
Full-text available
Controlled experiments are one approach to understanding the pathogenicity of etiologic agents to susceptible hosts. The recently discovered fungal pathogen, Batrachochytrium salamandrivorans (Bsal), has resulted in a surge of experimental investigations because of its potential to impact global salamander biodiversity. However, variation in experi...
Article
Full-text available
Batrachochytrium salamandrivorans (Bsal) is an emerging invasive pathogen that is highly pathogenic to salamander species. Modeling infection dynamics in this system can facilitate proactive efforts to mitigate this pathogen's impact on North American species. Given its widespread distribution and high abundance, the eastern newt (Notophthalmus vir...
Article
Full-text available
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Article
Ranaviruses are important emerging pathogens of ectothermic vertebrates, that threaten aquaculture and wildlife worldwide. A mortality event occurred in a cultured population of catfish‐like loach (Triplophysa siluorides) in Sichuan Province, China. Gross clinical signs of the affected fish included skin lesions and hemorrhagic ulcers, which are of...
Article
Full-text available
Novel outbreaks of emerging pathogens require rapid responses to enable successful mitigation. We simulated a 1-day emergency meeting where experts were engaged to recommend mitigation strategies for a new outbreak of the amphibian fungal pathogen Batrachochytrium salamandrivorans. Despite the inevitable uncertainty, experts suggested and discussed...
Article
Full-text available
Novel outbreaks of emerging pathogens require rapid responses to enable successful mitigation. We simulated a 1‐day emergency meeting where experts were engaged to recommend mitigation strategies for a new outbreak of the amphibian fungal pathogen Batrachochytrium salamandrivorans. Despite the inevitable uncertainty, experts suggested and discussed...
Article
A consequence of genetic recombination can be the evolution of highly virulent pathogen strains. Virulence can manifest through various mechanisms of host–pathogen interaction that facilitate transmission. We discovered a highly virulent chimeric ranavirus in Georgia, USA, estimated transmission parameters using controlled experiments, and develope...
Preprint
Full-text available
Discovered in 2013, Batrachochytrium salamandrivorans ( Bsal ) is an emerging amphibian pathogen that causes ulcerative skin lesions and multifocal erosion. A closely related pathogen, Batrachochytrium dendrobatidis ( Bd ), has devastated amphibian populations worldwide, suggesting that Bsal poses a significant threat to global salamander biodivers...
Article
Full-text available
The emerging fungal pathogen, Batrachochytrium salamandrivorans (Bsal), is a significant conservation threat to salamander biodiversity in Europe, although its potential to affect North American species is poorly understood. We tested the susceptibility of two genera (Eurycea and Pseudotriton) and three populations of lungless salamanders (Plethodo...
Article
Full-text available
Batrachochytrium dendrobatidis and B. salamandrivorans are important amphibian pathogens responsible for morbidity and mortality in free-ranging and captive frogs, salamanders, and caecilians. While B. dendrobatidis has a widespread global distribution, B. salamandrivorans has only been detected in amphibians in Asia and Europe. Although molecular...
Article
Full-text available
Ranaviruses have been identified as the cause of explosive disease outbreaks in amphibians worldwide and can be transmitted between hosts both via direct and indirect contact, in which humans might contribute to the translocation of contaminated material. The aim of this study was to evaluate the possible role of water sports in the human transloca...
Article
Understanding the distribution of pathogens across landscapes and their prevalence within host populations is a common aim of wildlife managers. Despite the need for unbiased estimates of pathogen occurrence and prevalence for planning effective management interventions, many researchers fail to account for imperfect pathogen detection. Instead raw...
Article
Full-text available
Human-mediated disease outbreaks due to poor biosecurity practices when processing animals in wild populations have been suspected. We tested whether not changing nitrile gloves between processing wood frog (Lithobates sylvaticus) tadpoles and co-housing individuals increased pathogen transmission and subsequent diseased-induced mortality caused by...
Data
R code for survival analyses; glove experiment. (R)
Data
R code for survival analyses; co-housing experiment. (R)
Presentation
Full-text available
Batrachochytrium salamandrivorans (Bsal) as an emerging fungal pathogen that caused rapid die-offs of naïve salamanders in Europe and predicts North America will soon experience similar devastation if no policy actions are taken and the pathogen emerges. In order to better understand Bsal pathogen dynamics we develop Susceptible-Infection-Susceptib...
Presentation
Epidemic dynamics of infectious diseases with multiple routes of transmission are complex. Mathematical models can be used to determine invasion potential and identify which transmission pathway is dominant, can ultimately help identify appropriate intervention strategies. We developed compartmental host-pathogen models to examine transmission dyna...
Article
Full-text available
Ranaviruses are pathogens of ectothermic vertebrates, including amphibians. We reviewed patterns of host range and virulence of ranaviruses in the context of virus genotype and postulate that patterns reflect significant variation in the historical and current host range of three groups of Ranavirus: FV3-like, CMTV-like and ATV-like ranaviruses. Ou...
Article
Western Tennessee is an important region for waterfowl during non-breeding periods, supporting >40% of the Mississippi Flyway population of American black ducks (Anas rubripes). Understanding habitat selection and activities of waterfowl during the non-breeding period is important for directed habitat management on national wildlife refuges and in...
Article
Ranaviruses are emerging pathogens of fish, amphibians, and reptiles. They threaten aquatic animal industries and wildlife worldwide. Our objective was to genetically characterize ranaviruses isolated during separate bullfrog die-offs that occurred eight years apart on the same North American farm. The earlier outbreak was due to a highly pathogeni...
Article
Despite calls for improved responses to emerging infectious diseases in wildlife, management is seldom considered until a disease has been detected in affected populations. Reactive approaches may limit the potential for control and increase total response costs. An alternative, proactive management framework can identify immediate actions that red...
Article
Members of the genus Ranavirus, one of five genera withinthe family Iridoviridae, encompass a group of large, doublestrandedDNA viruses that infect all three classes of ectothermicvertebrates: fish, amphibians, and reptiles. Ranaviruses areglobally emerging pathogens that cause considerable morbidityand mortality among diverse populations. In North...
Article
Rapid assessment of food production and subsequent availability is fundamental to evaluating wetland management practices and general habitat quality for waterfowl. Traditional methods of estimating food biomass (e.g., plot and core sampling) require considerable time, expertise, and cost. Rapid assessment models using plant measurements or scanned...
Article
Chinese giant salamander ranavirus (CGSRV) is an emerging pathogen in captive populations of the Chinese giant salamander (Andrias davidianus). We processed 140 morbid Chinese giant salamanders from seven captive breeding populations over five years, and describe the disease associated with CGSRV infection. The most common gross signs were signific...
Technical Report
Full-text available
This report summarizes work conducted in Year 6 (January 2016-September 2016) of the striped newt repatriation project within the Apalachicola National Forest (ANF).
Article
Full-text available
There is growing evidence that pathogens play a role in population declines and species extinctions. For small populations, disease-induced extinction may be especially probable. We estimated the susceptibility of two amphibian species of conservation concern (the dusky gopher frog [Lithobates sevosus] and boreal toad [Anaxyrus boreas boreas]) to a...
Article
The occurrence of emerging infectious diseases in wildlife populations is increasing, and changes in environmental conditions have been hypothesized as a potential driver. For example, warmer ambient temperatures might favor pathogens by providing more ideal conditions for propagation or by stressing hosts. Our objective was to determine if water t...
Article
Full-text available
Many migratory bird species, including the American Black Duck (Anas rubripes; hereafter black duck), face challenges to their survival during winter due to potentially limited resources and high energetic demands. These winter processes can be especially important for the population dynamics of migratory species. Despite stabilization of the overa...
Article
Full-text available
The recently (2013) identified pathogenic chytrid fungus, Batrachochytrium salamandrivorans (Bsal), poses a severe threat to the distribution and abundance of salamanders within the United States and Europe. Development of a response strategy for the potential, and likely, invasion of Bsal into the United States is crucial to protect global salaman...
Data
Number of live salamanders imported by taxa into the USA, 2004 to 2014 (source = USFWS LEMIS). USFWS LEMIS data (S1 Table) for live salamander imports into the US available at: http://www.amphibians.org/resources/tradedata/. Data requested in May 2015 under the US Freedom of Information Act. (PDF)
Article
Full-text available
Batrachochytrium salamandrivorans (Bsal) is an emerging fungal pathogen that has caused recent die-offs of native salamanders in Europe and is known to be lethal to at least some North American species in laboratory trials [1]. Bsal appears to have originated in Asia, and may have been introduced by humans into wild populations in Europe through co...
Article
Full-text available
Ranaviruses are pathogens that cause disease in ectothermic vertebrate species, and are responsible for die-off events in multiple taxa across the globe. Understanding the threat of ranavirus in wild and captive populations is a growing conservation and economic interest. Quantifying risk is a central premise to understanding the threat of a pathog...
Chapter
Full-text available
Ranaviruses have been identified in wild and captive populations of ectothermic vertebrates around the world. Ranavirus epidemics can result in a range of effects on their host populations, from apparently benign infections to mass mortality and local extirpation. In this chapter, we review the current status of ranavirus epidemiology and ecology i...
Book
The first book of its kind, this work discusses the global extent of ranaviruses, principles of ranavirus ecology and evolution. The research included provides guidance on designing ranavirus surveillance studies to determine risk. Ranaviruses are are double-stranded DNA viruses that cause hemorrhagic disease in amphibians, reptiles, and fish. Rana...
Chapter
Dr. Allan Granoff (1923–2012), who isolated the first ranavirus (Granoff et al. 1966), had, scattered throughout his office at St. Jude Children’s Research Hospital, a variety of frog-related items including the poem cited above. Although one of Allan’s isolates, Frog virus 3 (FV3), subsequently became the best-characterized member of both the genu...
Article
Full-text available
Emerging pathogens are a potential contributor to global amphibian declines. Ranaviruses, which infect ectothermic vertebrates and are common in aquatic environments, have been implicated in die-offs of at least 72 amphibian species worldwide. Most studies on the subject have focused on pool-breeding amphibians, and infection trends in other amphib...
Article
Full-text available
Amphibians are one of the most imperiled vertebrate groups, with pathogens playing a role in the decline of some species. Rare species are particularly vulnerable to extinction because populations are often isolated and exist at low abundance. The potential impact of pathogens on rare amphibian species has seldom been investigated. The dusky gopher...
Article
Full-text available
Mudflats are important stopover sites for shorebirds during migration, but management plans typically do not provide mudflat habitat in the reservoirs of the Tennessee River Valley (TRV) during May-July. In May 2010, flooding delayed drawdowns on Tennessee National Wildlife Refuge and created wetlands for shorebirds from May-August. We studied wetl...
Article
Full-text available
In 2009, juvenile pallid sturgeon Scaphirhynchus albus, reared at the Blind Pony State Fish Hatchery (Missouri, USA) to replenish dwindling wild stocks, experienced mass mortality. Histological examination revealed extensive necrosis of the haematopoietic tissues, and a virus was isolated from affected organs in cell culture and then observed by el...
Article
Ranaviruses are large double stranded DNA viruses of poikilothermic vertebrates including amphibians, reptiles and fish. In North America, ranaviral disease and ranavirus-related die-off events have been documented in all three classes. Ranaviruses are found worldwide, appear to be emerging in some regions, and are increasingly recognized as a thre...
Article
Full-text available
Amphibian declines and extinction have been attributed to many causes, including disease such as chytridiomycosis. Other pathogens may also contribute to declines, with ranavirus as the most likely candidate given reoccurring die-offs observed in the wild. We were interested in whether it is possible for ranavirus to cause extinction of a local, cl...
Article
Full-text available
Abstract Ranaviruses have been associated with mortality of lower vertebrates around the world. Frog virus 3 (FV3)-like ranaviruses have been isolated from different ectothermic vertebrate classes; however, few studies have demonstrated whether this pathogen can be transmitted among classes. Using FV3-like ranaviruses isolated from the American bul...
Article
Full-text available
Transmission is an essential process that contributes to the survival of pathogens. Ranaviruses are known to infect different classes of lower vertebrates including amphibians, fishes and reptiles. Differences in the likelihood of infection among ectothermic vertebrate hosts could explain the successful yearlong persistence of ranaviruses in aquati...
Article
Full-text available
Population-based habitat conservation planning for migrating and wintering waterfowl in North America is carried out by habitat Joint Venture (JV) initiatives and is based on the premise that food can limit demography (i.e. food limitation hypothesis). Consequently, planners use bioenergetic models to estimate food (energy) availability and populat...
Article
Full-text available
Use of disinfectants by biologists, veterinarians, and zoological facilities is a standard biosecurity procedure to prevent contamination and the spread of pathogens. We tested the efficacy of 5 disinfectants and 1 anti-fungal treatment, at 1 and 5 min contact durations, in inactivating Batrachochytrium dendrobatidis (Bd) grown on tryptone media. O...
Article
Full-text available
Wetlands are highly productive ecosystems that provide habitat for a diversity of wildlife species and afford various ecosystem services. Managing wetlands effectively requires an understanding of basic ecosystem processes, animal and plant life history strategies, and principles of wildlife management. Management techniques that are used differ de...
Article
Full-text available
Monitoring wetland wildlife is complex and requires use of various techniques to obtain robust population estimates. Herpetofauna, birds and mammals frequently inhabit wetlands and adjacent uplands. Sampling herpetofauna can include passive techniques such as visual encounter and breeding call surveys, and capture techniques that use nets and traps...
Technical Report
Full-text available
The Coastal Plains Institute (CPI) and US Forest Service entered a 5-year cost-share agreement in October 2010 to address the severe decline of the striped newt (Notophthalmus perstriatus) population within the Munson Sandhills (MS) of the Apalachicola National Forest (ANF). At that time, CPI and cooperators initiated a multifaceted study to: 1) in...
Technical Report
Full-text available