| terrestrial dispersal and potential environmental transmission of the amphibian chytrid fungus (batrachochytrium dendrobatidis). | dispersal and exposure to amphibian chytrid fungus (batrachochytrium dendrobatidis, bd) is not confined to the aquatic habitat, but little is known about pathways that facilitate exposure to wild terrestrial amphibians that do not typically enter bodies of water. we explored the possible spread of bd from an aquatic reservoir to terrestrial substrates by the emergence of recently metamorphosed infected amphibians and potential deposition of bd-positive residue on riparian vegetation in cusuco na ... | 2015 | 25927835 |
| the effects of a fungicide and chytrid fungus on anuran larvae in aquatic mesocosms. | the amphibian disease chytridiomycosis, caused by the pathogenic fungus batrachochytrium dendrobatidis (bd), has been linked to significant amphibian declines over the past three decades. the most severe effects of the pathogen have been primarily observed in relatively pristine areas that are not affected by many anthropogenic factors.one hypothesis concerning improved amphibian persistence with bd in disturbed landscapes is that contaminants may abate the effects of bd on amphibians. recent la ... | 2015 | 25913318 |
| widespread occurrence of bd in french guiana, south america. | the amphibian chytrid fungus batrachochytrium dendrobatidis (bd) is a purported agent of decline and extinction of many amphibian populations worldwide. its occurrence remains poorly documented in many tropical regions, including the guiana shield, despite the area's high amphibian diversity. we conducted a comprehensive assessment of bd in french guiana in order to (1) determine its geographical distribution, (2) test variation of bd prevalence among species in french guiana and compare it to e ... | 2015 | 25902035 |
| host species composition influences infection severity among amphibians in the absence of spillover transmission. | wildlife epidemiological outcomes can depend strongly on the composition of an ecological community, particularly when multiple host species are affected by the same pathogen. however, the relationship between host species richness and disease risk can vary with community context and with the degree of spillover transmission that occurs among co-occurring host species. we examined the degree to which host species composition influences infection by batrachochytrium dendrobatidis (bd), a widespre ... | 2015 | 25897383 |
| elevated corticosterone levels and changes in amphibian behavior are associated with batrachochytrium dendrobatidis (bd) infection and bd lineage. | few studies have examined the role hormones play in mediating clinical changes associated with infection by the parasite batrachochytrium dendrobatidis (bd). glucocorticoid (gc) hormones such as corticosteroids (cort) regulate homeostasis and likely play a key role in response to infection in amphibians. we explore the relationship between cort release rates and bd infection in tadpoles of the common midwife toad, alytes obstetricians, using a non-invasive water-borne hormone collection method a ... | 2015 | 25893675 |
| predicting the potential distribution of the amphibian pathogen batrachochytrium dendrobatidis in east and southeast asia. | batrachochytrium dendrobatidis (bd) is the pathogen responsible for chytridiomycosis, a disease that is associated with a worldwide amphibian population decline. in this study, we predicted the potential distribution of bd in east and southeast asia based on limited occurrence data. our goal was to design an effective survey area where efforts to detect the pathogen can be focused. we generated ecological niche models using the maximum-entropy approach, with alleviation of multicollinearity and ... | 2015 | 25850395 |
| chytrid fungus infections in laboratory and introduced xenopus laevis populations: assessing the risks for u.k. native amphibians. | the chytrid fungus batrachochytrium dendrobatidis (bd) is notorious amongst current conservation biology challenges, responsible for mass mortality and extinction of amphibian species. world trade in amphibians is implicated in global dissemination. exports of south african xenopus laevis have led to establishment of this invasive species on four continents. bd naturally infects this host in africa and now occurs in several introduced populations. however, no previous studies have investigated t ... | 2015 | 25843959 |
| amphibian symbiotic bacteria do not show a universal ability to inhibit growth of the global panzootic lineage of batrachochytrium dendrobatidis. | microbiomes associated with multicellular organisms influence the disease susceptibility of hosts. the potential exists for such bacteria to protect wildlife from infectious diseases, particularly in the case of the globally distributed and highly virulent fungal pathogen batrachochytrium dendrobatidis of the global panzootic lineage (b. dendrobatidis gpl), responsible for mass extinctions and population declines of amphibians. b. dendrobatidis gpl exhibits wide genotypic and virulence variation ... | 2015 | 25819964 |
| characterization of the carbohydrate binding module 18 gene family in the amphibian pathogen batrachochytrium dendrobatidis. | batrachochytrium dendrobatidis (bd) is the causative agent of chytridiomycosis responsible for worldwide decline in amphibian populations. previous analysis of the bd genome revealed a unique expansion of the carbohydrate-binding module family 18 (cbm18) predicted to be a sub-class of chitin recognition domains. cbm expansions have been linked to the evolution of pathogenicity in a variety of fungal species by protecting the fungus from the host. based on phylogenetic analysis and presence of ad ... | 2015 | 25819009 |
| susceptibility of amphibians to chytridiomycosis is associated with mhc class ii conformation. | the pathogenic chytrid fungus batrachochytrium dendrobatidis (bd) can cause precipitous population declines in its amphibian hosts. responses of individuals to infection vary greatly with the capacity of their immune system to respond to the pathogen. we used a combination of comparative and experimental approaches to identify major histocompatibility complex class ii (mhc-ii) alleles encoding molecules that foster the survival of bd-infected amphibians. we found that bd-resistant amphibians acr ... | 2015 | 25808889 |
| short term minimum water temperatures determine levels of infection by the amphibian chytrid fungus in alytes obstetricans tadpoles. | amphibians are one of the groups of wildlife most seriously threatened by emerging infectious disease. in particular, chytridiomycosis, caused by the aquatic fungus batrachochytrium dendrobatidis, is responsible for amphibian species declines on a worldwide scale. population-level outcomes following the introduction of the pathogen are context dependent and mediated by a large suite of abiotic and biotic variables. in particular, studies have shown that temperature has a key role in determining ... | 2015 | 25793985 |
| composition of symbiotic bacteria predicts survival in panamanian golden frogs infected with a lethal fungus. | symbiotic microbes can dramatically impact host health and fitness, and recent research in a diversity of systems suggests that different symbiont community structures may result in distinct outcomes for the host. in amphibians, some symbiotic skin bacteria produce metabolites that inhibit the growth of batrachochytrium dendrobatidis (bd), a cutaneous fungal pathogen that has caused many amphibian population declines and extinctions. treatment with beneficial bacteria (probiotics) prevents bd in ... | 2015 | 25788591 |
| white-nose syndrome fungus introduced from europe to north america. | the investigation of factors underlying the emergence of fungal diseases in wildlife has gained significance as a consequence of drastic declines in amphibians, where the fungus batrachochytrium dendrobatidis has caused the greatest disease-driven loss of biodiversity ever documented [1]. identification of the causative agent and its origin (native versus introduced) is a crucial step in understanding and controlling a disease [2]. whereas genetic studies on the origin of b. dendrobatidis have i ... | 2015 | 25784035 |
| amphibian pathogens at northern latitudes: presence of chytrid fungus and ranavirus in northeastern canada. | infections by the fungal pathogen batrachochytrium dendrobatidis (bd) and members of the genus ranavirus (rv) are increasingly reported as significant determinants of amphibian population die-offs. the complexity associated with their transmission and spatial distribution leads to an increase in demand for comprehensive reporting systems and global mapping of their distribution. here, we document the distribution of these 2 pathogens in a remote northern temperate lowland where environmental sen ... | 2015 | 25751857 |
| early 1900 s detection of batrachochytrium dendrobatidis in korean amphibians. | the pathogenic fungus batrachochytrium dendrobatidis (bd) is a major conservation concern because of its role in decimating amphibian populations worldwide. we used quantitative pcr to screen 244 museum specimens from the korean peninsula, collected between 1911 and 2004, for the presence of bd to gain insight into its history in asia. three specimens of rugosa emeljanovi (previously rana or glandirana rugosa), collected in 1911 from wonsan, north korea, tested positive for bd. histology of thes ... | 2015 | 25738656 |
| phylogenetic distribution of symbiotic bacteria from panamanian amphibians that inhibit growth of the lethal fungal pathogen batrachochytrium dendrobatidis. | the introduction of next-generation sequencing has allowed for greater understanding of community composition of symbiotic microbial communities. however, determining the function of individual members of these microbial communities still largely relies on culture-based methods. here, we present results on the phylogenetic distribution of a defensive functional trait of cultured symbiotic bacteria associated with amphibians. amphibians are host to a diverse community of cutaneous bacteria and so ... | 2015 | 25737297 |
| widespread presence of the pathogenic fungus batrachochytrium dendrobatidis in wild amphibian communities in madagascar. | amphibian chytridiomycosis, an emerging infectious disease caused by the fungus batrachochytrium dendrobatidis (bd), has been a significant driver of amphibian declines. while globally widespread, bd had not yet been reported from within madagascar. we document surveys conducted across the country between 2005 and 2014, showing bd's first record in 2010. subsequently, bd was detected in multiple areas, with prevalence reaching up to 100%. detection of bd appears to be associated with mid to high ... | 2015 | 25719857 |
| pathogenic chytrid fungus batrachochytrium dendrobatidis, but not b. salamandrivorans, detected on eastern hellbenders. | recent worldwide declines and extinctions of amphibian populations have been attributed to chytridiomycosis, a disease caused by the pathogenic fungus batrachochytrium dendrobatidis (bd). until recently, bd was thought to be the only batrachochytrium species that infects amphibians; however a newly described species, batrachochytrium salamandrivorans (bs), is linked to die-offs in european fire salamanders (salamandra salamandra). little is known about the distribution, host range, or origin of ... | 2015 | 25695636 |
| variation in the presence of anti-batrachochytrium dendrobatidis bacteria of amphibians across life stages and elevations in ecuador. | amphibian populations are decreasing worldwide due to a variety of factors. in south america, the chytrid fungus batrachochytrium dendrobatidis (bd) is linked to many population declines. the pathogenic effect of bd on amphibians can be inhibited by specific bacteria present on host skin. this symbiotic association allows some amphibians to resist the development of the disease chytridiomycosis. here, we aimed (1) to determine for the first time if specific anti-bd bacteria are present on amphib ... | 2015 | 25669915 |
| coqui frogs persist with the deadly chytrid fungus despite a lack of defensive antimicrobial peptides. | the amphibian skin fungus batrachochytrium dendrobatidis (bd) occurs widely in puerto rico and is thought to be responsible for the apparent extinction of 3 species of endemic frogs in the genus eleutherodactylus, known as coquis. to examine immune defenses which may protect surviving species, we induced secretion of skin peptides from adult common coqui frogs e. coqui collected from upland forests at el yunque. by matrix-assisted laser desorption/ionization time-of-flight (maldi-tof) mass spect ... | 2015 | 25667340 |
| differential efficiency among dna extraction methods influences detection of the amphibian pathogen batrachochytrium dendrobatidis. | chytridiomycosis, caused by the fungal pathogen batrachochytrium dendrobatidis (bd), is responsible for massive declines and extinctions of amphibians worldwide. the most common method for detecting bd is quantitative polymerase chain reaction (qpcr). qpcr is a highly sensitive detection technique, but its ability to determine the presence and accurately quantify the amount of bd is also contingent on the efficiency of the dna extraction method used prior to pcr. using qpcr, we compared the extr ... | 2015 | 25667331 |
| presence and prevalence of batrachochytrium dendrobatidis in commercial amphibians in mexico city. | in mexico city, native and exotic amphibians are commonly sold through the pet trade. this study investigates the presence of batrachochytrium dendrobatidis (bd) in native amphibians being sold at two commercial markets and at a herpetarium in mexico city. a total of 238 individuals (6 genera and 12 species) were tested for bd using real-time polymerase chain reaction (pcr) analysis. there were 197 bd-positive individuals (prevalence 82%) from five species of amphibians. hyla eximia from the mar ... | 2014 | 25632670 |
| 'salamander plague' on britain's doorstep. | chytridiomycosis can cause mass declines in amphibians, and the chytrid fungus batrachochytrium dendrobatidis is the classic cause of this disease. however, recently, a second strain of chytrid fungus has emerged in europe, resulting in major declines in fire salamanders. the zoological society of london (zsl) discussed this, and the implications for the uk, at a meeting in december in london. georgina mills reports. | 2015 | 25614547 |
| asian strain of batrachochytrium dendrobatidis is widespread in the western ghats, india. | we investigated the distribution of batrachochytrium dendrobatidis (bd) fungal infections in amphibians of the western ghats mountain range in india, based on data from 497 samples. eight individuals were positive, with genomic equivalents ranging from 2 to 785 zoospores. a single widespread bd strain identical to the haplotype endemic to asia was isolated. our findings suggest that chytridiomycosis is widespread among the endemic and threatened amphibians of the entire stretch of the western gh ... | 2015 | 25590776 |
| itraconazole treatment reduces batrachochytrium dendrobatidis prevalence and increases overwinter field survival in juvenile cascades frogs. | the global spread of the fungal pathogen batrachochytrium dendrobatidis (bd) has led to widespread extirpation of amphibian populations. during an intervention aimed at stabilizing at-risk populations, we treated wild-caught cascades frogs rana cascadae with the antifungal drug itraconazole. in fall 2012, we collected 60 recently metamorphosed r. cascadae from 1 of the 11 remnant populations in the cascades mountains (ca, usa). of these, 30 randomly selected frogs were treated with itraconazole ... | 2015 | 25590775 |
| batrachochytrium dendrobatidis exposure effects on foraging efficiencies and body size in anuran tadpoles. | chytridiomycosis, the amphibian disease caused by the pathogenic fungus batrachochytrium dendrobatidis (bd), is fatal to adults of many species. bd is largely sublethal to amphibian larvae; however, it is known to reduce larval (i.e. tadpole) growth rates, with possible long-term effects on population dynamics and fitness. we conducted an experiment to test how bd altered southern leopard frog lithobates sphenocephalus tadpole mouthpart damage, percentage of food ingested, and subsequent body si ... | 2015 | 25590774 |
| batrachochytrium dendrobatidis in natural and farmed louisiana crayfish populations: prevalence and implications. | the pathogenic chytrid fungus batrachochytrium dendrobatidis (bd) has been linked to global declines and extinctions of amphibians, making it one of the most devastating wildlife pathogens known. understanding the factors that affect disease dynamics in this system is critical for mitigating infection and protecting threatened species. crayfish are hosts of this pathogen and can transmit bd to amphibians. because they co-occur with susceptible amphibian communities, crayfish may be important alt ... | 2015 | 25590773 |
| temperature variability and moisture synergistically interact to exacerbate an epizootic disease. | climate change is altering global patterns of precipitation and temperature variability, with implications for parasitic diseases of humans and wildlife. a recent study confirmed predictions that increased temperature variability could exacerbate disease, because of lags in host acclimation following temperature shifts. however, the generality of these host acclimation effects and the potential for them to interact with other factors have yet to be tested. here, we report similar effects of host ... | 2015 | 25567647 |
| carotenoids and amphibians: effects on life history and susceptibility to the infectious pathogen, batrachochytrium dendrobatidis. | carotenoids are considered beneficial nutrients because they provide increased immune capacity. although carotenoid research has been conducted in many vertebrates, little research has been done in amphibians, a group that is experiencing global population declines from numerous causes, including disease. we raised two amphibian species through metamorphosis on three carotenoid diets to quantify the effects on life-history traits and post-metamorphic susceptibility to a fungal pathogen (batracho ... | 2015 | 27293690 |
| a new species of psychrophrynella (anura: craugastoridae) from the cordillera real, department la paz, bolivia. | we describe a new species of psychrophrynella from a single locality in the cordillera real, in the andes of department of la paz, bolivia. psychrophrynella teqta sp. nov. is highly variable in color pattern and differs from the species geographically closer mostly by presenting yellow or red blotches, usually absent in other species. in addition, the new species differs from all species in the genus because the males have a pulsed call. males of this species show parental care, and the high num ... | 2014 | 25543943 |
| more than skin deep: functional genomic basis for resistance to amphibian chytridiomycosis. | the amphibian-killing chytrid fungus batrachochytrium dendrobatidis (bd) is one of the most generalist pathogens known, capable of infecting hundreds of species globally and causing widespread population declines and extinctions. however, some host species are seemingly unaffected by bd, tolerating or clearing infections without clinical signs of disease. variation in host immune responses is commonly evoked for these resistant or tolerant species, yet to date, we have no direct comparison of am ... | 2014 | 25539724 |
| correlates of virulence in a frog-killing fungal pathogen: evidence from a california amphibian decline. | the fungal pathogen batrachochytrium dendrobatidis (bd) has caused declines and extinctions in amphibians worldwide, and there is increasing evidence that some strains of this pathogen are more virulent than others. while a number of putative virulence factors have been identified, few studies link these factors to specific epizootic events. we documented a dramatic decline in juvenile frogs in a bd-infected population of cascades frogs (rana cascadae) in the mountains of northern california and ... | 2015 | 25514536 |
| host-specific thermal profiles affect fitness of a widespread pathogen. | host behavior can interact with environmental context to influence outcomes of pathogen exposure and the impact of disease on species and populations. determining whether the thermal behaviors of individual species influence susceptibility to disease can help enhance our ability to explain and predict how and when disease outbreaks are likely to occur. the widespread disease chytridiomycosis (caused by the fungal pathogen batrachochytrium dendrobatidis, bd) often has species-specific impacts on ... | 2014 | 25505533 |
| experimental evolution alters the rate and temporal pattern of population growth in batrachochytrium dendrobatidis, a lethal fungal pathogen of amphibians. | virulence of infectious pathogens can be unstable and evolve rapidly depending on the evolutionary dynamics of the organism. experimental evolution can be used to characterize pathogen evolution, often with the underlying objective of understanding evolution of virulence. we used experimental evolution techniques (serial transfer experiments) to investigate differential growth and virulence of batrachochytrium dendrobatidis (bd), a fungal pathogen that causes amphibian chytridiomycosis. we teste ... | 2014 | 25478154 |
| trophic dynamics in an aquatic community: interactions among primary producers, grazers, and a pathogenic fungus. | free-living stages of parasites are consumed by a variety of predators, which might have important consequences for predators, parasites, and hosts. for example, zooplankton prey on the infectious stage of the amphibian chytrid fungus, batrachochytrium dendrobatidis (bd), a pathogen responsible for amphibian population declines and extinctions worldwide. predation on parasites is predicted to influence community structure and function, and affect disease risk, but relatively few studies have exp ... | 2015 | 25432573 |
| evidence of a salt refuge: chytrid infection loads are suppressed in hosts exposed to salt. | 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 is ... | 2015 | 25416999 |
| pathogenic fungus batrachochytrium dendrobatidis in marbled water frog telmatobius marmoratus: first record from lake titicaca, bolivia. | the pathogenic fungus batrachochytrium dendrobatidis (bd) has been associated with amphibian declines worldwide but has not been well-studied among critically endangered amphibian species in bolivia. we sampled free-living marbled water frogs telmatobius marmoratus (anura: leptodactylidae) from isla del sol, bolivia, for bd using skin swabs and quantitative polymerase chain reactions. we detected bd on 44% of t. marmoratus sampled. this is the first record of bd in amphibians from waters associa ... | 2014 | 25392045 |
| chytridiomycosis risk among central european amphibians based on surveillance data. | 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 pelophy ... | 2014 | 25392037 |
| the pathogen batrachochytrium dendrobatidis disturbs the frog skin microbiome during a natural epidemic and experimental infection. | symbiotic microbial communities may interact with infectious pathogens sharing a common host. the microbiome may limit pathogen infection or, conversely, an invading pathogen can disturb the microbiome. documentation of such relationships during naturally occurring disease outbreaks is rare, and identifying causal links from field observations is difficult. this study documented the effects of an amphibian skin pathogen of global conservation concern [the chytrid fungus batrachochytrium dendroba ... | 2014 | 25385615 |
| transition of chytrid fungus infection from mouthparts to hind limbs during amphibian metamorphosis. | the chytrid fungus, batrachochytrium dendrobatidis (bd), is implicated in worldwide amphibian declines. bd has been shown to qualitatively transition from the mouthparts of tadpoles to the hindlimbs during metamorphosis, but we lack evidence of consistency in the timing of this transition across amphibian species. we also do not have predictive functions for the abundance of bd in mouthparts and limbs as tadpoles develop or for the relationship between keratin and bd abundance. hence, researcher ... | 2015 | 25384612 |
| effects of pond salinization on survival rate of amphibian hosts infected with the chytrid fungus. | the chytrid fungus batrachochytrium dendrobatidis has been implicated in the decline and extinction of amphibian populations worldwide, but management options are limited. recent studies show that sodium chloride (nacl) has fungicidal properties that reduce the mortality rates of infected hosts in captivity. we investigated whether similar results can be obtained by adding salt to water bodies in the field. we increased the salinity of 8 water bodies to 2 or 4 ppt and left an additional 4 water ... | 2015 | 25354647 |
| swabbing often fails to detect amphibian chytridiomycosis under conditions of low infection load. | the pathogenic chytrid fungus, batrachochytrium dendrobatidis (denoted bd), causes large-scale epizootics in naïve amphibian populations. intervention strategies to rapidly respond to bd incursions require sensitive and accurate diagnostic methods. chytridiomycosis usually is assessed by quantitative polymerase chain reaction (qpcr) amplification of amphibian skin swabs. results based on this method, however, sometimes yield inconsistent results on infection status and inaccurate scores of infec ... | 2014 | 25333363 |
| batrachochytrium dendrobatidis detected in kihansi spray toads at a captive breeding facility (kihansi, tanzania). | the chytrid fungus batrachochytrium dendrobatidis (bd) is the aetiological agent of amphibian chytridiomycosis, a disease associated with global amphibian population declines. in november 2012, mass mortalities of kihansi spray toads nectophrynoides asperginis were observed at the kihansi captive breeding facility, located in the udzungwa mountains, tanzania. mortalities increased rapidly, and dead toads showed typical clinical signs of chytridiomycosis, including reddening of the skin that was ... | 2014 | 25266903 |
| survey of turkey's endemic amphibians for chytrid fungus batrachochytrium dendrobatidis. | we report a new survey for batrachochytrium dendrobatidis (bd) in turkey. we swabbed 228 individuals of 7 amphibian species (from 5 families) living in 2 locations (26-august national park and the turkish lakes district) in the southwestern anatolian region. the infection intensity of all the samples was determined using quantitative pcr. all 4 amphibian breeding sites and 4 amphibian species in 26-august national park were infected by bd, with the prevalence at each site ranging from 8 to 29%. ... | 2014 | 25266902 |
| in vitro sensitivity of the amphibian pathogen batrachochytrium dendrobatidis to antifungal therapeutics. | chytridiomycosis, a skin disease caused by batrachochytrium dendrobatidis, has caused amphibian declines worldwide. amphibians can be treated by percutaneous application of antimicrobials, but knowledge of in vitro susceptibility is lacking. using a modified broth microdilution method, we describe the in vitro sensitivity of two australian isolates of b. dendrobatidis to six antimicrobial agents. growth inhibition was observed, by measurement of optical density, with all agents. minimum inhibito ... | 2014 | 25241392 |
| detection of pathogenic batrachochytrium dendrobatidis using water filtration, animal and bait testing. | the pathogen batrachochytrium dendrobatidis (bd) can be challenging to detect at endangered amphibian reintroduction sites. pre-release bd detection can be confounded by imperfect animal sampling and the absence of animals. in study 1, we used historical bd-positive sites, to concurrently evaluate water filtrates and mouth bar (tadpoles) or skin swab (caudates) samples for bd using molecular beacon realtime pcr. in study 2, during a natural outbreak, we used pcr to detect bd from zoospore-attrac ... | 2014 | 25231013 |
| investigating differences across host species and scales to explain the distribution of the amphibian pathogen batrachochytrium dendrobatidis. | many pathogens infect more than one host species, and clarifying how these different hosts contribute to pathogen dynamics can facilitate the management of pathogens and can lend insight into the functioning of pathogens in ecosystems. in this study, we investigated a suite of native and non-native amphibian hosts of the pathogen batrachochytrium dendrobatidis (bd) across multiple scales to identify potential mechanisms that may drive infection patterns in the colorado study system. specifically ... | 2014 | 25222375 |
| heterogeneous occupancy and density estimates of the pathogenic fungus batrachochytrium dendrobatidis in waters of north america. | biodiversity losses are occurring worldwide due to a combination of stressors. for example, by one estimate, 40% of amphibian species are vulnerable to extinction, and disease is one threat to amphibian populations. the emerging infectious disease chytridiomycosis, caused by the aquatic fungus batrachochytrium dendrobatidis (bd), is a contributor to amphibian declines worldwide. bd research has focused on the dynamics of the pathogen in its amphibian hosts, with little emphasis on investigating ... | 2014 | 25222122 |
| development of antimicrobial peptide defenses of southern leopard frogs, rana sphenocephala, against the pathogenic chytrid fungus, batrachochytrium dendrobatidis. | amphibian species face the growing threat of extinction due to the emerging fungal pathogen batrachochytrium dendrobatidis, which causes the disease chytridiomycosis. antimicrobial peptides (amps) produced in granular glands of the skin are an important defense against this pathogen. little is known about the ontogeny of amp production or the impact of amps on potentially beneficial symbiotic skin bacteria. we show here that rana (lithobates) sphenocephala produces a mixture of four amps with ac ... | 2015 | 25218643 |
| extremely low prevalence of batrachochytrium dendrobatidis in frog populations from neotropical dry forest of costa rica supports the existence of a climatic refuge from disease. | population declines and extinctions of numerous species of amphibians, especially stream-breeding frogs, have been linked to the emerging infectious disease chytridiomycosis, caused by the chytrid fungus, batrachochytrium dendrobatidis. in central america, most of the 34 species of the craugastor punctariolus species group have disappeared in recent years in high- and low-elevation rainforests. distribution models for b. dendrobatidis and the continuous presence of the extirpated stream-dwelling ... | 2014 | 25212725 |
| defects in host immune function in tree frogs with chronic chytridiomycosis. | the amphibian chytrid fungus batrachochytrium dendrobatidis (bd) has caused mass mortality leading to population declines and extinctions in many frog species worldwide. the lack of host resistance may be due to fungal immunosuppressive effects that have been observed when bd is incubated with cultured lymphocytes, but whether in vivo host immunosuppression occurs is unknown. we used a broad range of hematologic and protein electrophoresis biomarkers, along with various functional tests, to asse ... | 2014 | 25211333 |
| inhibition of local immune responses by the frog-killing fungus batrachochytrium dendrobatidis. | amphibians are suffering unprecedented global declines. a leading cause is the infectious disease chytridiomycosis caused by the chytrid fungus batrachochytrium dendrobatidis. chytridiomycosis is a skin disease which disrupts transport of essential ions leading to death. soluble factors produced by b. dendrobatidis impair amphibian and mammalian lymphocytes in vitro, but previous studies have not shown the effects of these inhibitory factors in vivo. to demonstrate in vivo inhibition of immunity ... | 2014 | 25156734 |
| designing screening protocols for amphibian disease that account for imperfect and variable capture rates of individuals. | the amphibian chytrid fungus, batrachochytrium dendrobatidis, is one of the main factors in global amphibian decline. accurate knowledge of its presence and prevalence in an area is needed to trigger conservation actions. however, imperfect capture rates determine the number of individuals caught and tested during field surveys, and contribute to the uncertainty surrounding estimates of prevalence. screening programs should be planned with the objective of minimizing such uncertainty. we show ho ... | 2014 | 25154107 |
| batrachochytrium dendrobatidis infection dynamics vary seasonally in upstate new york, usa. | 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 ... | 2014 | 25144117 |
| baseline cutaneous bacteria of free-living new zealand native frogs (leiopelma archeyi and leiopelma hochstetteri) and implications for their role in defense against the amphibian chytrid (batrachochytrium dendrobatidis). | abstract knowledge of baseline cutaneous bacterial microbiota may be useful in interpreting diagnostic cultures from captive sick frogs and as part of quarantine or pretranslocation disease screening. bacteria may also be an important part of innate immunity against chytridiomycosis, a fungal skin disease caused by batrachochytrium dendrobatidis (bd). in february 2009, 92 distinct bacterial isolates from the ventral skin of 64 apparently healthy leiopelma archeyi and leiopelma hochstetteri nativ ... | 2014 | 25121401 |
| detection of the emerging amphibian pathogens batrachochytrium dendrobatidis and ranavirus in russia. | in a population of the european common toad bufo bufo from a rural pond in the region of lake glubokoe regional reserve in moscow province, russia, unexplained mass mortality events involving larvae and metamorphs have been observed over a monitoring period of >20 yr. we tested toads from this and a nearby site for the emerging amphibian pathogens batrachochytrium dendrobatidis (bd) and ranavirus (rv). both pathogens were detected, and at the rural pond site, with the above-noted losses and decl ... | 2014 | 25114047 |
| effects of amphibian chytrid fungus exposure on american toads in the presence of an insecticide. | abiotic factors such as pesticides may alter the impact of a pathogen on hosts, which could have implications for host-pathogen interactions and may explain variation in disease outbreaks in nature. in the present laboratory experiment, american toad (anaxyrus americanus) metamorphs were exposed to the amphibian chytrid fungal pathogen batrachochytrium dendrobatidis (bd) and environmentally relevant concentrations of the insecticide malathion to determine whether malathion altered the effects of ... | 2014 | 25099070 |
| the effects of the amphibian chytrid fungus, insecticide exposure, and temperature on larval anuran development and survival. | chytridiomycosis, a disease caused by batrachochytrium dendrobatidis (bd), has been implicated as a cause of amphibian declines. susceptibility may be influenced by environmental factors that suppress the immune response. the authors conducted a laboratory study to examine the effect of temperature, insecticide exposure, and bd exposure during larval anuran development. the authors examined the consequences of exposure to bd, an insecticide (carbaryl or malathion), and static or fluctuating temp ... | 2014 | 25098758 |
| unexpected rarity of the pathogen batrachochytrium dendrobatidis in appalachian plethodon salamanders: 1957-2011. | widespread population declines in terrestrial plethodon salamanders occurred by the 1980s throughout the appalachian mountains, the center of global salamander diversity, with no evident recovery. we tested the hypothesis that the historic introduction and spread of the pathogenic fungus batrachochytrium dendrobatidis (bd) into the eastern us was followed by plethodon population declines. we expected to detect elevated prevalence of bd prior to population declines as observed for central america ... | 2014 | 25084159 |
| effects of pesticide exposure and the amphibian chytrid fungus on gray treefrog (hyla chrysoscelis) metamorphosis. | pesticides are detectable in most aquatic habitats and have the potential to alter host-pathogen interactions. the amphibian chytrid fungus, batrachochytrium dendrobatidis (bd), has been associated with amphibian declines around the world. however, bd-associated declines are more prominent in some areas, despite nearly global distribution of bd, suggesting other factors contribute to disease outbreaks. in a laboratory study, the authors examined the effects of 6 different isolates of bd in the p ... | 2014 | 25044296 |
| amphibians acquire resistance to live and dead fungus overcoming fungal immunosuppression. | emerging fungal pathogens pose a greater threat to biodiversity than any other parasitic group, causing declines of many taxa, including bats, corals, bees, snakes and amphibians. currently, there is little evidence that wild animals can acquire resistance to these pathogens. batrachochytrium dendrobatidis is a pathogenic fungus implicated in the recent global decline of amphibians. here we demonstrate that three species of amphibians can acquire behavioural or immunological resistance to b. den ... | 2014 | 25008531 |
| temperature alone does not explain patterns of batrachochytrium dendrobatidis infections in the green frog lithobates clamitans. | batrachochytrium dendrobatidis (bd) is an invasive, waterborne fungal pathogen that has caused significant declines and extinctions of amphibian species worldwide. temperature is a major factor impacting the growth and spread of bd, but little is known regarding the associated patterns in natural habitats. this study analyzed the temperature-associated trends, as correlated with season and microhabitat, of bd prevalence and infection intensity in green frogs lithobates clamitans in a temperate e ... | 2014 | 24991844 |
| batrachochytrium dendrobatidis prevalence and haplotypes in domestic and imported pet amphibians in japan. | the international trade in amphibians is believed to have increased the spread of batrachochytrium dendrobatidis (bd), the fungal pathogen responsible for chytridiomycosis, which has caused a rapid decline in amphibian populations worldwide. we surveyed amphibians imported into japan and those held in captivity for a long period or bred in japan to clarify the bd infection status. samples were taken from 820 individuals of 109 amphibian species between 2008 and 2011 and were analyzed by a nested ... | 2014 | 24991744 |
| wetland characteristics influence disease risk for a threatened amphibian. | 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 severa ... | 2014 | 24988766 |
| interventions for reducing extinction risk in chytridiomycosis-threatened amphibians. | wildlife diseases pose an increasing threat to biodiversity and are a major management challenge. a striking example of this threat is the emergence of chytridiomycosis. despite diagnosis of chytridiomycosis as an important driver of global amphibian declines 15 years ago, researchers have yet to devise effective large-scale management responses other than biosecurity measures to mitigate disease spread and the establishment of disease-free captive assurance colonies prior to or during disease o ... | 2014 | 24975971 |
| genomic studies of disease-outcome in host--pathogen dynamics. | pathogens act as agents of evolutionary change in host populations, altering the host's allele frequencies and phenotypes through selection. the mechanisms underlying these adaptive changes depend on which defense strategy the host adopts upon infection. with increased anthropogenic change and loss of biodiversity, ecological impacts on adaptive processes may reduce the ability of hosts to evolve resistance, or to persist within their tolerance limits, thus increasing the capacity of pathogens t ... | 2014 | 24916476 |
| tagging frogs with passive integrated transponders causes disruption of the cutaneous bacterial community and proliferation of opportunistic fungi. | symbiotic bacterial communities play a key role in protecting amphibians from infectious diseases including chytridiomycosis, caused by the pathogenic fungus batrachochytrium dendrobatidis. events that lead to the disruption of the bacterial community may have implications for the susceptibility of amphibians to such diseases. amphibians are often marked both in the wild and in captivity for a variety of reasons, and although existing literature indicates that marking techniques have few negativ ... | 2014 | 24878599 |
| amphibian skin may select for rare environmental microbes. | host-microbe symbioses rely on the successful transmission or acquisition of symbionts in each new generation. amphibians host a diverse cutaneous microbiota, and many of these symbionts appear to be mutualistic and may limit infection by the chytrid fungus, batrachochytrium dendrobatidis, which has caused global amphibian population declines and extinctions in recent decades. using bar-coded 454 pyrosequencing of the 16s rrna gene, we addressed the question of symbiont transmission by examining ... | 2014 | 24858782 |
| from all to (nearly) none: tracing adaptin evolution in fungi. | the five adaptor protein (ap) complexes function in cargo-selection and coat-recruitment stages of vesicular transport in eukaryotic cells. much of what we know about ap complex function has come from experimental work using saccharomyces cerevisiae as a model. here, using a combination of comparative genomic and phylogenetic approaches we provide evolutionary context for the knowledge gained from this model system by searching the genomes of diverse fungi as well as a member of the sister group ... | 2014 | 24843829 |
| fighting a losing battle: vigorous immune response countered by pathogen suppression of host defenses in the chytridiomycosis-susceptible frog atelopus zeteki. | the emergence of the disease chytridiomycosis caused by the chytrid fungus batrachochytrium dendrobatidis (bd) has been implicated in dramatic global amphibian declines. although many species have undergone catastrophic declines and/or extinctions, others appear to be unaffected or persist at reduced frequencies after bd outbreaks. the reasons behind this variance in disease outcomes are poorly understood: differences in host immune responses have been proposed, yet previous studies suggest a la ... | 2014 | 24841130 |
| assessing host extinction risk following exposure to batrachochytrium dendrobatidis. | wildlife diseases are increasingly recognized as a major threat to biodiversity. chytridiomycosis is an emerging infectious disease of amphibians caused by the fungus batrachochytrium dendrobatidis (bd). using a mathematical model and simulations, we study its effects on a generic riparian host population with a tadpole and adult life stage. an analytical expression for the basic reproduction quotient, qo, of the pathogen is derived. by sampling the entire relevant parameter space, we perform a ... | 2014 | 24807247 |
| susceptibility to the amphibian chytrid fungus varies with ontogeny in the direct-developing frog, eleutherodactylus coqui. | age-related differences in susceptibility to infectious disease are known from a wide variety of plant and animal taxonomic groups. for example, the immature immune systems of young vertebrates, along with limited prior exposure to pathogens and behavioral factors, can place juveniles at greater risk of acquiring and succumbing to a pathogen. we studied the ontogenetic susceptibility of terrestrial direct-developing frogs (eleutherodactylus coqui) to the fungal pathogen, batrachochytrium dendrob ... | 2014 | 24807186 |
| interacting symbionts and immunity in the amphibian skin mucosome predict disease risk and probiotic effectiveness. | pathogenesis is strongly dependent on microbial context, but development of probiotic therapies has neglected the impact of ecological interactions. dynamics among microbial communities, host immune responses, and environmental conditions may alter the effect of probiotics in human and veterinary medicine, agriculture and aquaculture, and the proposed treatment of emerging wildlife and zoonotic diseases such as those occurring on amphibians or vectored by mosquitoes. here we use a holistic measu ... | 2014 | 24789229 |
| evaluation of amphotericin b and chloramphenicol as alternative drugs for treatment of chytridiomycosis and their impacts on innate skin defenses. | chytridiomycosis, an amphibian skin disease caused by the emerging fungal pathogen batrachochytrium dendrobatidis, has been implicated in catastrophic global amphibian declines. the result is an alarming decrease in amphibian diversity that is a great concern for the scientific community. clinical trials testing potential antifungal drugs are needed to identify alternative treatments for amphibians infected with this pathogen. in this study, we quantified the mics of chloramphenicol (800 μg/ml), ... | 2014 | 24771024 |
| chytridiomycosis: a global threat to amphibians. | chytridiomycosis, which is caused by batrachochytrium dendrobatidis, is an emerging infectious disease of amphibians. the disease is one of the main causes of the global decline in amphibians. the aetiological agent is ubiquitous, with worldwide distribution, and affects a large number of amphibian species in several biomes. in the last decade, scientific research has substantially increased knowledge of the aetiological agent and the associated infection. however, important epidemiological aspe ... | 2013 | 24761737 |
| the lethal fungus batrachochytrium dendrobatidis is present in lowland tropical forests of far eastern panamá. | 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 ... | 2014 | 24740162 |
| immunomodulation in post-metamorphic northern leopard frogs, lithobates pipiens, following larval exposure to polybrominated diphenyl ether. | pollutants and disease are factors implicated in amphibian population declines, and it is hypothesized that these factors exert a synergistic adverse effect, which is mediated by pollutant-induced immunosuppression. polybrominated diphenyl ethers (pbdes) are ubiquitous pollutants that can exert immunotoxicity, making them of interest to test effects on amphibian immune function. we orally exposed lithobates (rana) pipiens tadpoles to environmentally realistic levels (0-634 ng/g wet diet) of a pe ... | 2014 | 24735054 |
| reduced itraconazole concentration and durations are successful in treating batrachochytrium dendrobatidis infection in amphibians. | amphibians are experiencing the greatest decline of any vertebrate class and a leading cause of these declines is a fungal pathogen, batrachochytrium dendrobatidis (bd), which causes the disease chytridiomycosis. captive assurance colonies are important worldwide for threatened amphibian species and may be the only lifeline for those in critical threat of extinction. maintaining disease free colonies is a priority of captive managers, yet safe and effective treatments for all species and across ... | 2014 | 24686573 |
| fungal infection intensity and zoospore output of atelopus zeteki, a potential acute chytrid supershedder. | amphibians vary in their response to infection by the amphibian-killing chytrid fungus, batrachochytrium dendrobatidis (bd). highly susceptible species are the first to decline and/or disappear once bd arrives at a site. these competent hosts likely facilitate bd proliferation because of ineffective innate and/or acquired immune defenses. we show that atelopus zeteki, a highly susceptible species that has undergone substantial population declines throughout its range, rapidly and exponentially i ... | 2014 | 24675899 |
| over-wintering tadpoles of mixophyes fasciolatus act as reservoir host for batrachochytrium dendrobatidis. | batrachochytrium dendrobatidis (bd), a cutaneous amphibian fungus that causes the lethal disease chytridiomycosis, has been implicated as a cause of many amphibian declines. bd can tolerate low temperatures with an optimum thermal range from 17-24°c. it has been shown that bd infection may result in species extinction, avoiding the transmission threshold presented by density dependent transmission theory. prevalence of bd during autumn and winter has been shown to be as low as 0% in some species ... | 2014 | 24647532 |
| environmental determinants of recent endemism of batrachochytrium dendrobatidis infections in amphibian assemblages in the absence of disease outbreaks. | the inconsistent distribution of large-scale infection mediated die-offs and the subsequent population declines of several animal species, urges us to understand how, when, and why species are affected by disease. it is often unclear when or under what conditions a pathogen constitutes a threat to a host. often, variation of environmental conditions plays a role. globally batrachochytrium dendrobatidis (bd) causes amphibian declines; however, host responses are inconsistent and this fungus appea ... | 2014 | 24641583 |
| stress and chytridiomycosis: exogenous exposure to corticosterone does not alter amphibian susceptibility to a fungal pathogen. | recent emergence and spread of the amphibian fungal pathogen, batrachochytrium dendrobatidis (bd) has been attributed to a number of factors, including environmental stressors that increase host susceptibility to bd. physiological stress can increase circulating levels of the hormone, corticosterone, which can alter a host's physiology and affect its susceptibility to pathogens. we experimentally elevated whole-body levels of corticosterone in both larval and post-metamorphic amphibians, and sub ... | 2014 | 24610865 |
| presence of the amphibian chytrid fungus batrachochytrium dendrobatidis in native amphibians exported from madagascar. | the emerging infectious disease chytridiomycosis is driven by the spread of amphibian chytrid fungus (batrachochytrium dendrobatidis, bd), a highly virulent pathogen threatening global amphibian biodiversity. although pandemic in distribution, previous intensive field surveys have failed to detect bd in madagascar, a biodiversity hotspot home to hundreds of endemic amphibian species. due to the presence of bd in nearby continental africa and the ecological crisis that can be expected following e ... | 2014 | 24599336 |
| first evidence of amphibian chytrid fungus (batrachochytrium dendrobatidis) and ranavirus in hong kong amphibian trade. | the emerging infectious amphibian diseases caused by amphibian chytrid fungus (batrachochytrium dendrobatidis, bd) and ranaviruses are responsible for global amphibian population declines and extinctions. although likely to have been spread by a variety of activities, transcontinental dispersal appears closely associated with the international trade in live amphibians. the territory of hong kong reports frequent, high volume trade in amphibians, and yet the presence of bd and ranavirus have not ... | 2014 | 24599268 |
| chironomidae bloodworms larvae as aquatic amphibian food. | different species of chironomids larvae (diptera: chironomidae) so-called bloodworms are widely distributed in the sediments of all types of freshwater habitats and considered as an important food source for amphibians. in our study, three species of chironomidae (baeotendipes noctivagus, benthalia dissidens, and chironomus riparius) were identified in 23 samples of larvae from belgium, poland, russia, and ukraine provided by a distributor in belgium. we evaluated the suitability of these sample ... | 2014 | 24535989 |
| trypan blue dye is an effective and inexpensive way to determine the viability of batrachochytrium dendrobatidis zoospores. | batrachochytrium dendrobatidis (bd) has been implicated in hundreds of amphibian declines and is the focus of a vast amount of research. despite this, there is no reported efficient way to assess bd viability. discriminating between live and dead bd would help determine the dose of live bd zoospores and whether factors have lethal or sublethal effects on bd. we tested whether trypan blue, a common stain to discriminate live and dead cells, could be used to assess bd viability. we show that the p ... | 2014 | 24519684 |
| long-term endemism of two highly divergent lineages of the amphibian-killing fungus in the atlantic forest of brazil. | the recent global spread of the amphibian-killing fungus [batrachochytrium dendrobatidis (bd)] has been closely tied to anthropogenic activities; however, regional patterns of spread are not completely understood. using historical samples, we can test whether bd was a spreading or endemic pathogen in a region within a particular time frame, because those two disease states provide different predictions for the regional demographic dynamics and population genetics of bd. testing historical patter ... | 2014 | 24471406 |
| a tale of two lineages: unexpected, long-term persistence of the amphibian-killing fungus in brazil. | for the past 17 years, scientists have been compiling a list of amphibian species susceptible to infection by the amphibian-killing chytrid fungus, batrachochytrium dendrobatidis (bd), all over the world, with >500 species infected on every continent except antarctica (olson et al.). where bd has been found, the impacts on amphibians has been one of two types: either bd arrives into a naïve amphibian population followed by a mass die-off and population declines (e.g. lips et al.), or bd is prese ... | 2014 | 24471404 |
| batrachochytrium dendrobatidis in aquatic caecilians (typhlonectes natans): a series of cases from two institutions. | infection with the fungal organism batrachochytrium dendrobatidis was documented in two captive populations of aquatic caecilians (typhlonectes natans), including 24 confiscated animals at the bronx zoo's wildlife health center and two captive-born animals at the phoenix zoo. the animals at the bronx zoo were asymptomatic, and infection was discovered during quarantine polymerase chain reaction screening. both animals at the phoenix zoo were clinically ill, and batrachochytrium dendrobatidis inf ... | 2013 | 24450061 |
| nikkomycin z is an effective inhibitor of the chytrid fungus linked to global amphibian declines. | fungal infections in humans, wildlife, and plants are a growing concern because of their devastating effects on human and ecosystem health. in recent years, populations of many amphibian species have declined, and some have become extinct due to chytridiomycosis caused by the fungal pathogen batrachochytrium dendrobatidis. for some endangered amphibian species, captive colonies are the best intermediate solution towards eventual reintroduction, and effective antifungal treatments are needed to c ... | 2014 | 24433676 |
| prevalence of batrachochytrium dendrobatidis in 120 archived specimens of lithobates catesbeianus (american bullfrog) collected in california, 1924-2007. | the chytrid fungus, batrachochytrium dendrobatidis (bd), has been identified as a major cause of the recent worldwide amphibian decline. numerous species in north america alone are under threat or have succumbed to bd-driven population extinctions. the american bullfrog (lithobates catesbeianus) has been reported as a tolerant carrier of bd. in this report, we used a qpcr assay to test 120 archived american bullfrog specimens collected between 1924 and 2007 in california, usa and baja california ... | 2013 | 24419668 |
| retrospective survey of museum specimens reveals historically widespread presence of batrachochytrium dendrobatidis in china. | chytridiomycosis, caused by the chytrid fungus batrachochytrium dendrobatidis (bd), has been implicated in amphibian population declines worldwide. however, no amphibian declines or extinctions associated with bd have been reported in asia. to investigate the history of this pathogen in china, we examined 1,007 museum-preserved amphibian specimens of 80 species collected between 1933 and 2009. bd was detected in 60 individuals (6.0%), with the earliest case of bd infection occurring in one speci ... | 2014 | 24419667 |
| microscopic aquatic predators strongly affect infection dynamics of a globally emerged pathogen. | research on emerging infectious wildlife diseases has placed particular emphasis on host-derived barriers to infection and disease. this focus neglects important extrinsic determinants of the host/pathogen dynamic, where all barriers to infection should be considered when ascertaining the determinants of infectivity and pathogenicity of wildlife pathogens. those pathogens with free-living stages, such as fungi causing catastrophic wildlife declines on a global scale, must confront lengthy exposu ... | 2014 | 24374305 |
| thermal physiology, disease, and amphibian declines on the eastern slopes of the andes. | rising temperatures, a widespread consequence of climate change, have been implicated in enigmatic amphibian declines from habitats with little apparent human impact. the pathogenic fungus batrachochytrium dendrobatidis (bd), now widespread in neotropical mountains, may act in synergy with climate change causing collapse in thermally stressed hosts. we measured the thermal tolerance of frogs along a wide elevational gradient in the tropical andes, where frog populations have collapsed. we used t ... | 2014 | 24372791 |
| effects of visible implanted elastomer marking on physiological traits of frogs. | amphibians possess innate immune defences, including antimicrobial peptides and symbiotic bacterial communities, that can protect them from infectious diseases, including chytridiomycosis. on-going research is attempting to use amphibian symbiotic bacteria to develop probiotic treatments that can protect hosts from the causative agent of chytridiomycosis, the fungal pathogen batrachochytrium dendrobatidis. events that cause disruption of symbiotic bacterial communities or deplete peptide stores ... | 2014 | 27293663 |
| first line of defence: the role of sloughing in the regulation of cutaneous microbes in frogs. | amphibian populations worldwide are currently experiencing unprecedented declines due to the combined effects of emerging infectious disease and climate change. the skin is the first line of defence in preventing establishment of pathogens and associated infections. although amphibians undergo regular sloughing of the outer layer of the skin, the potential for regular sloughing to play a role in influencing cutaneous microbial populations and pathogens has been largely overlooked. in the present ... | 2014 | 27293633 |
| daphnia predation on the amphibian chytrid fungus and its impacts on disease risk in tadpoles. | direct predation upon parasites has the potential to reduce infection in host populations. for example, the fungal parasite of amphibians, batrachochytrium dendrobatidis (bd), is commonly transmitted through a free-swimming zoospore stage that may be vulnerable to predation. potential predators of bd include freshwater zooplankton that graze on organisms in the water column. we tested the ability of two species of freshwater crustacean (daphnia magna and d. dentifera) to consume bd and to reduce ... | 2013 | 24324864 |
| elevation, temperature, and aquatic connectivity all influence the infection dynamics of the amphibian chytrid fungus in adult frogs. | infectious diseases can cause population declines and even extinctions. the amphibian chytrid fungus, batrachochytrium dendrobatidis (bd), has caused population declines and extinctions in amphibians on most continents. in the tropics, research on the dynamics of this disease has focused on amphibian populations in mountainous areas. in most of these areas, high and low elevation sites are connected by an assemblage of streams that may transport the infectious stage of the pathogen from high to ... | 2013 | 24324786 |
| linking manipulative experiments to field data to test the dilution effect. | the dilution effect, the hypothesis that biodiversity reduces disease risk, has received support in many systems. however, few dilution effect studies have linked mechanistic experiments to field patterns to establish both causality and ecological relevance. we conducted a series of laboratory experiments and tested the dilution effect hypothesis in an amphibian-batrachochytrium dendrobatidis (bd) system and tested for consistency between our laboratory experiments and field patterns of amphibia ... | 2014 | 24289288 |
| is chytridiomycosis driving darwin's frogs to extinction? | darwin's frogs (rhinoderma darwinii and r. rufum) are two species of mouth brooding frogs from chile and argentina that have experienced marked population declines. rhinoderma rufum has not been found in the wild since 1980. we investigated historical and current evidence of batrachochytrium dendrobatidis (bd) infection in rhinoderma spp. to determine whether chytridiomycosis is implicated in the population declines of these species. archived and live specimens of rhinoderma spp., sympatric amph ... | 2013 | 24278196 |