51
|
Scheele BC, Driscoll DA, Fischer J, Fletcher AW, Hanspach J, Vörös J, Hartel T. Landscape context influences chytrid fungus distribution in an endangered European amphibian. Anim Conserv 2015. [DOI: 10.1111/acv.12199] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- B. C. Scheele
- Fenner School of Environment and Society; Australian National University; Canberra Australia
| | - D. A. Driscoll
- Fenner School of Environment and Society; Australian National University; Canberra Australia
| | - J. Fischer
- Faculty of Sustainability; Leuphana University Lueneburg; Lueneburg Germany
| | - A. W. Fletcher
- Faculty of Sustainability; Leuphana University Lueneburg; Lueneburg Germany
| | - J. Hanspach
- Faculty of Sustainability; Leuphana University Lueneburg; Lueneburg Germany
| | - J. Vörös
- Department of Zoology; Hungarian Natural History Museum; Budapest Hungary
| | - T. Hartel
- Faculty of Sustainability; Leuphana University Lueneburg; Lueneburg Germany
- Environmental Science Department; Sapientia Hungarian University of Transylvania; Cluj-Napoca Romania
| |
Collapse
|
52
|
Evidence of a salt refuge: chytrid infection loads are suppressed in hosts exposed to salt. Oecologia 2014; 177:901-910. [PMID: 25416999 DOI: 10.1007/s00442-014-3157-6] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 11/10/2014] [Indexed: 10/24/2022]
Abstract
With the incidence of emerging infectious diseases on the rise, it is becoming increasingly important to identify refuge areas that protect hosts from pathogens and therefore prevent population declines. For the chytrid fungus Batrachochytrium dendrobatidis, temperature and humidity refuge areas for amphibian hosts exist but are difficult to manipulate. Other environmental features that may affect the outcome of infection include water quality, drying regimes, abundance of alternate hosts and isolation from other hosts. We identified relationships between water bodies with these features and infection levels in the free-living hosts inhabiting them. Where significant relationships were identified, we used a series of controlled experiments to test for causation. Infection loads were negatively correlated with the salt concentration of the aquatic habitat and the degree of water level fluctuation and positively correlated with fish abundance. However, only the relationship with salt was confirmed experimentally. Free-living hosts inhabiting water bodies with mean salinities of up to 3.5 ppt had lower infection loads than those exposed to less salt. The experiment confirmed that exposure to sodium chloride concentrations >2 ppt significantly reduced host infection loads compared to no exposure (0 ppt). These results suggest that the exposure of amphibians to salt concentrations found naturally in lentic habitats may be responsible for the persistence of some susceptible species in the presence of B. dendrobatidis. By manipulating the salinity of water bodies, it may be possible to create refuges for declining amphibians, thus allowing them to be reintroduced to their former ranges.
Collapse
|
53
|
Balá V, Vojar J, Civi P, Andera M, Rozínek R. Chytridiomycosis risk among Central European amphibians based on surveillance data. DISEASES OF AQUATIC ORGANISMS 2014; 112:1-8. [PMID: 25392037 DOI: 10.3354/dao02799] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The Czech Republic hosts a surprisingly rich biodiversity of amphibians representing the majority of amphibian species present in all of Central and Eastern Europe. Surveillance data of Batrachochytrium dendrobatidis (Bd) collected during 2008 to 2012 were analysed for basic patterns of prevalence and infection intensity among species, age groups and localities. In addition, an investigation was made into possible data bias due to varying PCR inhibition. Infection prevalence in the genus Pelophylax was significantly higher than in other sampled taxa, while Bombina and Bufo were infected with intermediate prevalence. Individual mortalities putatively caused by chytridiomycosis were detected in Bombina and Bufo, but not in Pelophylax. Differences among localities were seen to modulate the pathogen's infection rate and influence overall individual infection intensities. PCR inhibition occurred significantly more often in samples from the genus Pelophylax than in other tested taxa (Bufo bufo, B. viridis, Bombina bombina, Pelobates fuscus and Rana dalmatina). Although we found no completely inhibited samples within the genus Bombina, the infection loads were lower in the sample set processed without bovine serum albumin, suggesting some level of PCR inhibition. The combination of high Bd prevalence with no apparent deleterious effect and the high dispersal abilities of water frogs predispose them to act as vectors for chytridiomycosis. It is possible that the role of Pelophylax frogs in the spread of Bd is overlooked due to a large proportion of unrecognized false negatives, but this issue needs further confirmation.
Collapse
Affiliation(s)
- Vojtech Balá
- Department of Biology and Wildlife Diseases, Faculty of Veterinary Hygiene and Ecology, University of Veterinary and Pharmaceutical Sciences Brno, Palackého trˇ. 1/3, Brno 612 42, Czech Republic
| | | | | | | | | |
Collapse
|
54
|
Lenker MA, Savage AE, Becker CG, Rodriguez D, Zamudio KR. Batrachochytrium dendrobatidis infection dynamics vary seasonally in upstate New York, USA. DISEASES OF AQUATIC ORGANISMS 2014; 111:51-60. [PMID: 25144117 DOI: 10.3354/dao02760] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The amphibian disease chytridiomycosis, caused by the fungus Batrachochytrium dendrobatidis (Bd), is a major cause of worldwide amphibian declines and extinctions. Although several studies indicate that Bd prevalence and infection intensity vary seasonally, temporal variation of Bd at high-latitude sites, such as the northeastern USA, is still poorly characterized. We screened amphibians for Bd monthly at 2 study sites in New York State from April to October 2011 and used quantitative polymerase chain reaction (qPCR) to detect and quantify temporal variability in Bd infection prevalence and intensity. We found pronounced seasonal variation in both Bd infection prevalence and intensity at the community level, and our data indicate that this pattern is due to a few species (Lithobates catesbeianus, L. clamitans, and Notophthalmus viridescens) that drive temporal variability in disease dynamics. Amphibian body mass and sex were significant predictors of infection intensity but not infection prevalence. Understanding the temporal dynamics of Bd host-pathogen interactions provides important insight into regional, seasonal, and host-specific determinants of disease outbreaks. Further, our study elucidates the most relevant and informative timing for Bd surveys in temperate amphibian assemblages. Seasonal variation of infection dynamics suggests that Bd surveys from different sampling time points are not comparable, and summer surveys to evaluate chytridiomycosis may significantly underestimate Bd prevalence and intensity, leading to false conclusions about the severity of chytridiomycosis-induced amphibian mortality and population decline.
Collapse
Affiliation(s)
- Melissa A Lenker
- Cornell University, Department of Ecology and Evolutionary Biology, Ithaca, NY 14853, USA
| | | | | | | | | |
Collapse
|
55
|
Saenz D, Hall TL, Kwiatkowski MA. Effects of urbanization on the occurrence of Batrachochytrium dendrobatidis: do urban environments provide refuge from the amphibian chytrid fungus? Urban Ecosyst 2014. [DOI: 10.1007/s11252-014-0398-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
56
|
Longo AV, Burrowes PA, Zamudio KR. Genomic Studies of Disease-Outcome in Host-Pathogen Dynamics. Integr Comp Biol 2014; 54:427-38. [DOI: 10.1093/icb/icu073] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
|
57
|
Heard GW, Scroggie MP, Clemann N, Ramsey DSL. Wetland characteristics influence disease risk for a threatened amphibian. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2014; 24:650-662. [PMID: 24988766 DOI: 10.1890/13-0389.1] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Identifying determinants of the probability and intensity of infections is important for understanding the epidemiology of wildlife diseases, and for managing their impact on threatened species. Chytridiomycosis, caused by the fungal pathogen Batrachochytrium dendrobatidis, has decimated populations of some amphibians. However, recent studies have identified important environmental constraints on the disease, related to the pathogen's physiological tolerances. In this study, we identified several intrinsic and extrinsic determinants of the probability and intensity of chytrid infections for the threatened growling grass frog (Litoria raniformis) in southeastern Australia, and used mark-recapture to estimate the effect of chytrid infections on the probability of survival of these frogs. Water temperature and salinity had negative effects on both the probability and intensity of chytrid infections. We coupled models of the infection process with a model of the effect of chytrid infections on the probability of survival to assess variation in the impact of chytridiomycosis between wetlands with differing temperature and salinity profiles. Our results suggest that warm, saline wetlands may be refuges from chytridiomycosis for L. raniformis, and should be priorities for protection. Our results also suggest that management actions that increase water temperature (e.g., reducing canopy shading) and salinity (e.g., complementing inflows with groundwater) could be trialed to reduce the impacts of chytridiomycosis on this species. This and other recent studies highlight the value of research on environmental risk factors for chytridiomycosis.
Collapse
|
58
|
Rebollar EA, Hughey MC, Harris RN, Domangue RJ, Medina D, Ibáñez R, Belden LK. The lethal fungus Batrachochytrium dendrobatidis is present in lowland tropical forests of far eastern Panamá. PLoS One 2014; 9:e95484. [PMID: 24740162 PMCID: PMC3989334 DOI: 10.1371/journal.pone.0095484] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2013] [Accepted: 03/27/2014] [Indexed: 11/19/2022] Open
Abstract
The fungal disease chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), is one of the main causes of amphibian population declines and extinctions all over the world. In the Neotropics, this fungal disease has caused catastrophic declines in the highlands as it has spread throughout Central America down to Panamá. In this study, we determined the prevalence and intensity of Bd infection in three species of frogs in one highland and four lowland tropical forests, including two lowland regions in eastern Panamá in which the pathogen had not been detected previously. Bd was present in all the sites sampled with a prevalence ranging from 15-34%, similar to other Neotropical lowland sites. The intensity of Bd infection on individual frogs was low, ranging from average values of 0.11-24 zoospore equivalents per site. Our work indicates that Bd is present in anuran communities in lowland Panamá, including the Darién province, and that the intensity of the infection may vary among species from different habitats and with different life histories. The population-level consequences of Bd infection in amphibian communities from the lowlands remain to be determined. Detailed studies of amphibian species from the lowlands will be essential to determine the reason why these species are persisting despite the presence of the pathogen.
Collapse
Affiliation(s)
- Eria A. Rebollar
- Department of Biology, James Madison University, Harrisonburg, Virginia, United States of America
- * E-mail:
| | - Myra C. Hughey
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Reid N. Harris
- Department of Biology, James Madison University, Harrisonburg, Virginia, United States of America
| | - Rickie J. Domangue
- Department of Mathematics and Statistics, James Madison University, Harrisonburg, Virginia, United States of America
| | - Daniel Medina
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Roberto Ibáñez
- Smithsonian Tropical Research Institute, Balboa, Ancón, Republic of Panamá
| | - Lisa K. Belden
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| |
Collapse
|
59
|
Environmental attributes to respiratory diseases of small ruminants. Vet Med Int 2014; 2014:853627. [PMID: 24782941 PMCID: PMC3981018 DOI: 10.1155/2014/853627] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2013] [Revised: 02/13/2014] [Accepted: 02/15/2014] [Indexed: 02/06/2023] Open
Abstract
Respiratory diseases are the major disease crisis in small ruminants. A number of pathogenic microorganisms have been implicated in the development of respiratory disease but the importance of environmental factors in the initiation and progress of disease can never be overemphasized. They irritate the respiratory tree producing stress in the microenvironment causing a decline in the immune status of the small ruminants and thereby assisting bacterial, viral, and parasitic infections to break down the tissue defense barriers. Environmental pollutants cause acute or chronic reactions as they deposit on the alveolar surface which are characterized by inflammation or fibrosis and the formation of transitory or persistent tissue manifestation. Some of the effects of exposures may be immediate, whereas others may not be evident for many decades. Although the disease development can be portrayed as three sets of two-way communications (pathogen-environment, host-environment, and host-pathogen), the interactions are highly variable. Moreover, the environmental scenario is never static; new compounds are introduced daily making a precise evaluation of the disease burden almost impossible. The present review presents a detailed overview of these interactions and the ultimate effect on the respiratory health of sheep and goat.
Collapse
|
60
|
Rodriguez D, Becker CG, Pupin NC, Haddad CFB, Zamudio KR. Long-term endemism of two highly divergent lineages of the amphibian-killing fungus in the Atlantic Forest of Brazil. Mol Ecol 2014; 23:774-87. [DOI: 10.1111/mec.12615] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 11/21/2013] [Accepted: 11/23/2013] [Indexed: 11/30/2022]
Affiliation(s)
- D. Rodriguez
- Department of Ecology and Evolutionary Biology; Cornell University; Ithaca NY 14853 USA
- Department of Biology; Texas State University; San Marcos TX 78666 USA
| | - C. G. Becker
- Department of Ecology and Evolutionary Biology; Cornell University; Ithaca NY 14853 USA
| | - N. C. Pupin
- Departamento de Zoologia; Instituto de Biociências; Universidade Estadual Paulista; 13506-900 Rio Claro SP Brazil
| | - C. F. B. Haddad
- Departamento de Zoologia; Instituto de Biociências; Universidade Estadual Paulista; 13506-900 Rio Claro SP Brazil
| | - K. R. Zamudio
- Department of Ecology and Evolutionary Biology; Cornell University; Ithaca NY 14853 USA
| |
Collapse
|
61
|
Puschendorf R, Hodgson L, Alford RA, Skerratt LF, VanDerWal J. Underestimated ranges and overlooked refuges from amphibian chytridiomycosis. DIVERS DISTRIB 2013. [DOI: 10.1111/ddi.12091] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Affiliation(s)
| | | | | | - Lee F. Skerratt
- School of Public Health, Tropical Medicine and Rehabilitation Sciences; James Cook University; Townsville; Qld 4811; Australia
| | | |
Collapse
|