1
|
McGrath-Blaser SE, McGathey N, Pardon A, Hartmann AM, Longo AV. Invasibility of a North American soil ecosystem to amphibian-killing fungal pathogens. Proc Biol Sci 2024; 291:20232658. [PMID: 38628130 PMCID: PMC11021929 DOI: 10.1098/rspb.2023.2658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 03/19/2024] [Indexed: 04/19/2024] Open
Abstract
North American salamanders are threatened by intercontinental spread of chytridiomycosis, a deadly disease caused by the fungal pathogen Batrachochytrium salamandrivorans (Bsal). To predict potential dispersal of Bsal spores to salamander habitats, we evaluated the capacity of soil microbial communities to resist invasion. We determined the degree of habitat invasibility using soils from five locations throughout the Great Smoky Mountains National Park, a region with a high abundance of susceptible hosts. Our experimental design consisted of replicate soil microcosms exposed to different propagule pressures of the non-native pathogen, Bsal, and an introduced but endemic pathogen, B. dendrobatidis (Bd). To compare growth and competitive interactions, we used quantitative PCR, live/dead cell viability assays, and full-length 16S rRNA sequencing. We found that soil microcosms with intact bacterial communities inhibited both Bsal and Bd growth, but inhibitory capacity diminished with increased propagule pressure. Bsal showed greater persistence than Bd. Linear discriminant analysis (LDA) identified the family Burkolderiaceae as increasing in relative abundance with the decline of both pathogens. Although our findings provide evidence of environmental filtering in soils, such barriers weakened in response to pathogen type and propagule pressure, showing that habitats vary their invasibility based on properties of their local microbial communities.
Collapse
Affiliation(s)
| | - Natalie McGathey
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Allison Pardon
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Arik M. Hartmann
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Ana V. Longo
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| |
Collapse
|
2
|
Hartmann A, Subramaniam K, Conrad C, Viadanna PHO, Waltzek TB, Longo AV. Genomic characterization of two ranavirus isolates identified from a gopher frog ( Lithobates capito) and a striped newt ( Notophthalmus perstriatus) during a mass mortality event in Florida. Microbiol Resour Announc 2024:e0001724. [PMID: 38651908 DOI: 10.1128/mra.00017-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2024] [Accepted: 04/04/2024] [Indexed: 04/25/2024] Open
Abstract
Two ranavirus isolates were recovered from anuran and salamander samples collected during an amphibian mass mortality event in North-Central Florida in 2021. Phylogenetic analyses of the full genomes confirmed that the two isolates were nearly identical and strains of the species Frog virus 3.
Collapse
Affiliation(s)
- Arik Hartmann
- Department of Biology, University of Florida, Gainesville, Florida, USA
| | - Kuttichantran Subramaniam
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
| | - Cody Conrad
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Pedro H O Viadanna
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- School of Biological Sciences, Washington State University, Pullman, Washington, USA
| | - Thomas B Waltzek
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, USA
- Department of Veterinary Microbiology and Pathology, Washington Animal Disease Diagnostic Laboratory, College of Veterinary Medicine, Washington State University, Pullman, Washington, USA
| | - Ana V Longo
- Department of Biology, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
3
|
Bacigalupe LD, Solano‐Iguaran JJ, Longo AV, Gaitán‐Espitia JD, Valenzuela‐Sánchez A, Alvarado‐Rybak M, Azat C. Nor climate nor human impact factors: Chytrid infection shapes the skin bacterial communities of an endemic amphibian in a biodiversity hotspot. Ecol Evol 2024; 14:e11249. [PMID: 38590552 PMCID: PMC10999949 DOI: 10.1002/ece3.11249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 03/27/2024] [Indexed: 04/10/2024] Open
Abstract
The bacterial communities of the amphibian skin (i.e., the bacteriome) are critical to the host's innate immune system. However, it is unclear how different drivers can alter this function by modulating the bacteriome's structure. Our aim was to assess the extent to which different host attributes and extrinsic factors influence the structure of the bacterial communities of the skin. Skin bacterial diversity was examined in 148 individuals of the four-eyed frog (Pleurodema thaul) from 16 localities spanning almost 1800 km in latitude. The richness and beta diversity of bacterial families and the richness and abundance of Bd-inhibitory bacterial genera were used to describe their structure. Predictors associated with the host (developmental stage, genetic lineage, individual Batrachochytrium dendrobatidis [Bd] infection status) and the landscape (current climate, degree of anthropogenic disturbance) were used in the statistical modeling in an information theoretical approach. Bd infection and host developmental stage were the only predictors affecting bacteriome richness, with Bd+ individuals and postmetamorphic stages (adults and juveniles) having higher richness than Bd- ones and tadpoles. High diversity in Bd+ individuals is not driven by bacterial genera with known anti-Bd properties. Beta diversity was not affected by Bd infection and was mainly a consequence of bacterial family turnover rather than nestedness. Finally, for those bacterial genera known to have inhibitory effects on chytrid, Bd+ individuals had a slightly higher diversity than Bd- ones. Our study confirms an association between Bd infection and the host developmental stage with the bacterial communities of the skin of P. thaul. Unexpectedly, macroclimate and human impact factors do not seem to play a role in shaping the amphibian skin microbiome. Our study exemplifies that focusing on a single host-parasite system over a large geographic scale can provide essential insights into the factors driving host-parasite-bacteriome interactions.
Collapse
Affiliation(s)
| | - Jaiber J. Solano‐Iguaran
- Instituto de Ciencias Ambientales y EvolutivasUniversidad Austral de ChileValdiviaChile
- Departamento de Salud HidrobiológicaInstituto de Fomento PesqueroPuerto MonttChile
| | - Ana V. Longo
- Department of BiologyUniversity of FloridaGainesvilleFloridaUSA
| | - Juan D. Gaitán‐Espitia
- School of Biological Sciences and the SWIRE Institute of Marine ScienceThe University of Hong KongHong KongSARChina
| | | | - Mario Alvarado‐Rybak
- Núcleo de Ciencias Aplicadas en Ciencias Veterinarias y AgronómicasUniversidad de Las AméricasSantiagoChile
| | - Claudio Azat
- Sustainability Research Centre & PhD in Conservation MedicineUniversidad Andres BelloSantiagoChile
| |
Collapse
|
4
|
Mulder KP, Savage AE, Gratwicke B, Longcore JE, Bronikowski E, Evans M, Longo AV, Kurata NP, Walsh T, Pasmans F, McInerney N, Murray S, Martel A, Fleischer RC. Sequence capture identifies fastidious chytrid fungi directly from host tissue. Fungal Genet Biol 2024; 170:103858. [PMID: 38101696 DOI: 10.1016/j.fgb.2023.103858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 12/04/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023]
Abstract
The chytrid fungus Batrachochytrium dendrobatidis (Bd) was discovered in 1998 as the cause of chytridiomycosis, an emerging infectious disease causing mass declines in amphibian populations worldwide. The rapid population declines of the 1970s-1990s were likely caused by the spread of a highly virulent lineage belonging to the Bd-GPL clade that was introduced to naïve susceptible populations. Multiple genetically distinct and regional lineages of Bd have since been isolated and sequenced, greatly expanding the known biological diversity within this fungal pathogen. To date, most Bd research has been restricted to the limited number of samples that could be isolated using culturing techniques, potentially causing a selection bias for strains that can grow on media and missing other unculturable or fastidious strains that are also present on amphibians. We thus attempted to characterize potentially non-culturable genetic lineages of Bd from distinct amphibian taxa using sequence capture technology on DNA extracted from host tissue and swabs. We focused our efforts on host taxa from two different regions that likely harbored distinct Bd clades: (1) wild-caught leopard frogs (Rana) from North America, and (2) a Japanese Giant Salamander (Andrias japonicus) at the Smithsonian Institution's National Zoological Park that exhibited signs of disease and tested positive for Bd using qPCR, but multiple attempts failed to isolate and culture the strain for physiological and genetic characterization. We successfully enriched for and sequenced thousands of fungal genes from both host clades, and Bd load was positively associated with number of recovered Bd sequences. Phylogenetic reconstruction placed all the Rana-derived strains in the Bd-GPL clade. In contrast, the A. japonicus strain fell within the Bd-Asia3 clade, expanding the range of this clade and generating additional genomic data to confirm its placement. The retrieved ITS locus matched public barcoding data from wild A. japonicus and Bd infections found on other amphibians in India and China, suggesting that this uncultured clade is widespread across Asia. Our study underscores the importance of recognizing and characterizing the hidden diversity of fastidious strains in order to reconstruct the spatiotemporal and evolutionary history of Bd. The success of the sequence capture approach highlights the utility of directly sequencing pathogen DNA from host tissue to characterize cryptic diversity that is missed by culture-reliant approaches.
Collapse
Affiliation(s)
- Kevin P Mulder
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium; Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA.
| | - Anna E Savage
- Department of Biology, University of Central Florida, Orlando, FL, USA
| | - Brian Gratwicke
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Joyce E Longcore
- School of Biology and Ecology, University of Maine, Orono, ME, USA
| | - Ed Bronikowski
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Matthew Evans
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Ana V Longo
- Department of Biology, University of Florida, Gainesville, FL, USA
| | - Naoko P Kurata
- Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA; Department of Natural Resources and the Environment, Cornell University, Ithaca, NY, USA; Department of Ichthyology, American Museum of Natural History, New York, NY, USA
| | - Tim Walsh
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Frank Pasmans
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Nancy McInerney
- Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - Suzan Murray
- Smithsonian's National Zoo and Conservation Biology Institute, Washington, DC, USA
| | - An Martel
- Wildlife Health Ghent, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Robert C Fleischer
- Center for Conservation Genomics, Smithsonian National Zoo and Conservation Biology Institute, Washington, DC, USA
| |
Collapse
|
5
|
Hartmann AM, McGrath-Blaser SE, Colón-Piñeiro Z, Longo AV. Ontogeny drives shifts in skin bacterial communities in facultatively paedomorphic salamanders. Microbiology (Reading) 2023; 169:001399. [PMID: 37815535 PMCID: PMC10634365 DOI: 10.1099/mic.0.001399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 10/02/2023] [Indexed: 10/11/2023]
Abstract
Microbiomes are major determinants of host growth, development and survival. In amphibians, host-associated bacteria in the skin can inhibit pathogen infection, but many processes can influence the structure and composition of the community. Here we quantified the shifts in skin-associated bacteria across developmental stages in the striped newt (Notophthalmus perstriatus), a threatened salamander species with a complex life history and vulnerable to infection by the amphibian chytrid fungus Batrachochytrium dendrobatidis and ranavirus. Our analyses show that pre-metamorphic larval and paedomorphic stages share similar bacterial compositions, and that the changes in the microbiome coincided with physiological restructuring during metamorphosis. Newts undergoing metamorphosis exhibited microbiome compositions that were intermediate between paedomorphic and post-metamorphic stages, further supporting the idea that metamorphosis is a major driver of host-associated microbes in amphibians. We did not find support for infection-related disruption of the microbiome, though infection replicates were small for each respective life stage.
Collapse
Affiliation(s)
- Arik M. Hartmann
- Department of Biology, University of Florida, Gainesville, Florida, USA
| | | | | | - Ana V. Longo
- Department of Biology, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
6
|
Longo AV, Lips KR, Zamudio KR. Evolutionary ecology of host competence after a chytrid outbreak in a naive amphibian community. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220130. [PMID: 37305909 DOI: 10.1098/rstb.2022.0130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023] Open
Abstract
Naive multi-host communities include species that may differentially maintain, transmit and amplify novel pathogens; therefore, we expect species to fill distinct roles during infectious disease emergence. Characterizing these roles in wildlife communities is challenging because most disease emergence events are unpredictable. Here, we used field-collected data to investigate how species-specific attributes influenced the degree of exposure, probability of infection, and pathogen intensity, during the emergence of the fungal pathogen Batrachochytrium dendrobatidis (Bd) in a highly diverse tropical amphibian community. Our findings confirmed that ecological traits commonly evaluated as correlates of decline were positively associated with infection prevalence and intensity at the species level during the outbreak. We identified key hosts that disproportionally contributed to transmission dynamics in this community and found a signature of phylogenetic history in disease responses associated with increased pathogen exposure via shared life-history traits. Our findings establish a framework that could be applied in conservation efforts to identify key species driving disease dynamics under enzootics before reintroducing amphibians back into their original communities. Reintroductions of supersensitive hosts that are unable to overcome infections will limit the success of conservation programmes by amplifying the disease at the community level. This article is part of the theme issue 'Amphibian immunity: stress, disease and ecoimmunology'.
Collapse
Affiliation(s)
- Ana V Longo
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Karen R Lips
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Kelly R Zamudio
- Department of Integrative Biology, College of Natural Sciences, The University of Texas, Austin, TX 78712, USA
| |
Collapse
|
7
|
Longo AV, Hamja A, Forget S, Chenais S. 80-μs pulsewidth from a circulation-free diode-pumped liquid organic laser limited by thermal blooming. Opt Express 2023; 31:23533-23541. [PMID: 37475434 DOI: 10.1364/oe.480590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 12/08/2022] [Indexed: 07/22/2023]
Abstract
Continuous-wave laser emission is challenging to obtain in organic lasers, whether in the solid or liquid form, a limitation caused by long-lived triplet states and by thermal effects. In liquid dye lasers, both issues can be fixed by rapidly flowing the dye, which is technically complex and prevents those lasers to be further miniaturized or easily integrated. Here we address the issue of the maximal pulsewidth that can be obtained in liquid dye lasers in the absence of any dye flow, in a compact and cost-effective diode-pumped laser system. Pulses as long as 80 μs have been obtained, thanks to the combination of a hemispherical resonator design, almost insensitive to thermal-lens effects, and an intentional mismatch between pump and cavity spatial modes. The limitation in pulse duration is shown to be entirely due to thermal blooming, and more specifically to diffraction losses brought by the spherical aberration of the thermal lens.
Collapse
|
8
|
Torres-Sánchez M, Longo AV. Linking pathogen-microbiome-host interactions to explain amphibian population dynamics. Mol Ecol 2022; 31:5784-5794. [PMID: 36130047 DOI: 10.1111/mec.16701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 09/13/2022] [Accepted: 09/16/2022] [Indexed: 01/13/2023]
Abstract
Symbiotic interactions can determine the evolutionary trajectories of host species, influencing genetic variation through selection and changes in demography. In the context of strong selective pressures such as those imposed by infectious diseases, symbionts providing defences could contribute to increase host fitness upon pathogen emergence. Here, we generated genome-wide data of an amphibian species to find evidence of evolutionary pressures driven by two skin symbionts: a batrachochytrid fungal pathogen and an antifungal bacterium. Using demographic modelling, we found evidence of decreased effective population size, probably due to pathogen infections. Additionally, we investigated host genetic associations with infection status, antifungal bacterium abundance and overall microbiome diversity using structural equation models. We uncovered relatively lower nucleotide diversity in infected frogs and potential heterozygote advantage to recruit the candidate beneficial symbiont and fight infections. Our models indicate that environmental conditions have indirect effects on symbiont abundance through both host body traits and microbiome diversity. Likewise, we uncovered a potential offsetting effect among host heterozygosity-fitness correlations, plausibly pointing to different ecological and evolutionary processes among the three species due to dynamic interactions. Our findings revealed that evolutionary pressures not only arise from the pathogen but also from the candidate beneficial symbiont, and both interactions shape the genetics of the host. Our results advance knowledge about multipartite symbiotic relationships and provide a framework to model ecological and evolutionary dynamics in wild populations. Finally, our study approach can be applied to inform conservation actions such as bioaugmentation strategies for other imperilled amphibians affected by infectious diseases.
Collapse
Affiliation(s)
| | - Ana V Longo
- Department of Biology, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
9
|
Torres-Sánchez M, Villate J, McGrath-Blaser S, Longo AV. Panzootic chytrid fungus exploits diverse amphibian host environments through plastic infection strategies. Mol Ecol 2022; 31:4558-4570. [PMID: 35796691 DOI: 10.1111/mec.16601] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 06/28/2022] [Accepted: 06/30/2022] [Indexed: 11/29/2022]
Abstract
While some pathogens are limited to single species, others can colonize many hosts, likely contributing to the emergence of novel disease outbreaks. Despite this biodiversity threat, traits associated with host niche expansions are not well understood in multi-host pathogens. Here, we aimed to uncover functional machinery driving multi-host invasion by focusing on Batrachochytrium dendrobatidis (Bd), a pathogen that infects the skin of hundreds of amphibians worldwide. We performed a meta-analysis of Bd gene expression using data from published infection experiments and newly generated profiles. We analyzed Bd transcriptomic landscapes across the skin of 14 host species, reconstructed Bd isolates phylogenetic relationships, and inferred the origin and evolutionary history of differentially expressed genes under a phylogenetic framework comprising other 12 zoosporic fungi. Bd displayed plastic infection strategies when challenged by hosts with different disease susceptibility. Our analyses identified sets of differentially expressed genes under host environments with similar infection outcome. We stressed nutritional immunity and gene silencing as important processes required to overcome challenging skin environments in less susceptible hosts. Overall, Bd genes expressed during amphibian skin exploitation have arisen mainly via gene duplications with great family expansions, increasing the gene copy events previously described for this fungal species. Finally, we provide a comprehensive gene dataset that can be used to further examine eco-evolutionary hypotheses for this host-pathogen system. Our study supports the idea that host environments exert contrasting selective pressures, such that gene expression plasticity could be one of the evolutionary keys leading to the success of multi-host pathogens.
Collapse
Affiliation(s)
| | - Jennifer Villate
- Department of Biology, University of Florida, 32611, Gainesville, FL
| | | | - Ana V Longo
- Department of Biology, University of Florida, 32611, Gainesville, FL
| |
Collapse
|
10
|
Longo AV. Metabarcoding approaches in amphibian disease ecology: Disentangling the functional contributions of skin bacteria on disease outcome. Integr Comp Biol 2022; 62:252-261. [PMID: 35640913 DOI: 10.1093/icb/icac062] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 05/10/2022] [Accepted: 05/25/2022] [Indexed: 01/09/2023] Open
Abstract
Molecular technologies have revolutionized the field of wildlife disease ecology, allowing the detection of outbreaks, novel pathogens, and invasive strains. In particular, metabarcoding approaches, defined here as tools used to amplify and sequence universal barcodes from a single sample (e.g., 16S rRNA for bacteria, ITS for fungi, 18S rRNA for eukaryotes), are expanding our traditional view of host-pathogen dynamics by integrating microbial interactions that modulate disease outcome. Here, I provide an analysis from the perspective of the field of amphibian disease ecology, where the emergence of multi-host pathogens has caused global declines and species extinctions. I re-analyzed an experimental mesocosm dataset to infer the functional profiles of the skin microbiomes of coqui frogs (Eleutherodactylus coqui), an amphibian species that is consistently found infected with the fungal pathogen Batrachochytrium dendrobatidis and has high turnover of skin bacteria driven by seasonal shifts. I found that the metabolic activities of microbiomes operate at different capacities depending on the season. Global enrichment of predicted functions was more prominent during the warm-wet season, indicating that microbiomes during the cool-dry season were either depauperate, resistant to new bacterial colonization, or that their functional space was more saturated. These findings suggest important avenues to investigate how microbes regulate population growth and contribute to host physiological processes. Overall, this study highlights the current challenges and future opportunities in the application of metabarcoding to investigate the causes and consequences of disease in wild systems.
Collapse
Affiliation(s)
- Ana V Longo
- University of Florida, Department of Biology, PO Box 118525, Gainesville, FL
| |
Collapse
|
11
|
Hartmann AM, Maddox ML, Ossiboff RJ, Longo AV. Sustained Ranavirus Outbreak Causes Mass Mortality and Morbidity of Imperiled Amphibians in Florida. Ecohealth 2022; 19:8-14. [PMID: 35000043 DOI: 10.1007/s10393-021-01572-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Accepted: 11/10/2021] [Indexed: 06/14/2023]
Abstract
A persistent 2-month long outbreak of Ranavirus in a natural community of amphibians contributed to a mass die-off of gopher frog tadpoles (Lithobates capito) and severe disease in striped newts (Notophthalmus perstriatus) in Florida. Ongoing mortality in L. capito and disease signs in N. perstriatus continued for 5 weeks after the first observation. Hemorrhagic disease and necrosis were diagnosed from pathological examination of L. capito tadpoles. We confirmed detection of a frog virus 3 (FV3)-like Ranavirus via quantitative PCR in all species. Our findings highlight the susceptibility of these species to Rv and the need for long-term disease surveillance during epizootics.
Collapse
Affiliation(s)
- Arik M Hartmann
- Department of Biology, College of Liberal Arts and Sciences, University of Florida, Gainesville, FL, 32611, USA.
| | - Max L Maddox
- Department of Wildlife Ecology and Conservation, College of Agriculture and Life Sciences, University of Florida, Gainesville, FL, 32611, USA
| | - Robert J Ossiboff
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, 32610, USA
| | - Ana V Longo
- Department of Biology, College of Liberal Arts and Sciences, University of Florida, Gainesville, FL, 32611, USA
| |
Collapse
|
12
|
DiRenzo GV, Longo AV, Muletz-Wolz CR, Pessier AP, Goodheart JA, Lips KR. Correction to: Plethodontid salamanders show variable disease dynamics in response to Batrachochytrium salamandrivorans chytridiomycosis. Biol Invasions 2021. [DOI: 10.1007/s10530-021-02578-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
13
|
Friday B, Holzheuser C, Lips KR, Longo AV. Preparing for invasion: Assessing risk of infection by chytrid fungi in southeastern plethodontid salamanders. J Exp Zool A Ecol Integr Physiol 2020; 333:829-840. [PMID: 33174393 DOI: 10.1002/jez.2427] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 09/30/2020] [Accepted: 10/23/2020] [Indexed: 12/31/2022]
Abstract
Understanding the responses of naïve communities to the invasion of multihost pathogens requires accurate estimates of susceptibility across taxa. In the Americas, the likely emergence of a second amphibian pathogenic fungus (Batrachochytrium salamandrivorans, Bsal) calls for new ways of prioritizing disease mitigation among species due to the high diversity of naïve hosts with prior B. dendrobatidis (Bd) infections. Here, we applied the concept of pathogenic potential to quantify the virulence of chytrid fungi on naïve amphibians and evaluate species for conservation efforts in the event of an outbreak. The benefit of this measure is that it combines and summarizes the variation in disease effects into a single numerical index, allowing for comparisons across species, populations or groups of individuals that may inherently exhibit differences in susceptibility. As a proof of concept, we obtained standardized responses of disease severity by performing experimental infections with Bsal on five plethodontid salamanders from southeastern United States. Four out of five species carried natural infections of Bd at the start of the experiments. We showed that Bsal exhibited its highest value of pathogenic potential in a species that is already declining (Desmognathus auriculatus). We find that this index provides additional information beyond the standard measures of disease prevalence, intensity, and mortality, because it leveraged these disease parameters within each categorical group. Scientists and practitioners could use this measure to justify research, funding, trade, or conservation measures.
Collapse
Affiliation(s)
- Brenna Friday
- Department of Biology, University of Maryland, College Park, Maryland, USA.,Department of Biological Sciences, Wayne State University, Detroit, Michigan, USA
| | - Chace Holzheuser
- Department of Biology, University of Maryland, College Park, Maryland, USA.,Department of Biological Science, Florida State University, Tallahassee, Florida, USA
| | - Karen R Lips
- Department of Biology, University of Maryland, College Park, Maryland, USA
| | - Ana V Longo
- Department of Biology, University of Florida, Gainesville, Florida, USA
| |
Collapse
|
14
|
McDonald CA, Longo AV, Lips KR, Zamudio KR. Incapacitating effects of fungal coinfection in a novel pathogen system. Mol Ecol 2020; 29:3173-3186. [PMID: 32310322 DOI: 10.1111/mec.15452] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 03/16/2020] [Accepted: 04/08/2020] [Indexed: 12/20/2022]
Abstract
As globalization lowers geographic barriers to movement, coinfection with novel and enzootic pathogens is increasingly likely. Novel and enzootic pathogens can interact synergistically or antagonistically, leading to increased or decreased disease severity. Here we examine host immune responses to coinfection with two closely related fungal pathogens: Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). Both pathogens have had detrimental effects on amphibian populations, with Bd now largely enzootic, while Bsal is currently spreading and causing epizootics. Recent experimental work revealed that newts coinfected with Bd and Bsal had significantly higher mortality than those infected with either pathogen alone. Here we characterize host immunogenomic responses to chytrid coinfection relative to single infection. Across several classes of immune genes including pattern recognition receptors, cytokines, and MHC, coinfected host gene expression was weakly upregulated or comparable to that seen in single Bd infection, but significantly decreased when compared to Bsal infection. Combined with strong complement pathway downregulation and keratin upregulation, these results indicate that coinfection with Bd and Bsal compromises immune responses active against Bsal alone. As Bsal continues to invade naïve habitats where Bd is enzootic, coinfection will be increasingly common. If other Bd-susceptible species in the region have similar responses, interactions between the two pathogens could cause severe population and community-level declines.
Collapse
Affiliation(s)
- Cait A McDonald
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| | - Ana V Longo
- Department of Biology, University of Maryland, College Park, MD, USA
| | - Karen R Lips
- Department of Biology, University of Maryland, College Park, MD, USA
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| |
Collapse
|
15
|
Scheele BC, Pasmans F, Skerratt LF, Berger L, Martel A, Beukema W, Acevedo AA, Burrowes PA, Carvalho T, Catenazzi A, De la Riva I, Fisher MC, Flechas SV, Foster CN, Frías-Álvarez P, Garner TWJ, Gratwicke B, Guayasamin JM, Hirschfeld M, Kolby JE, Kosch TA, La Marca E, Lindenmayer DB, Lips KR, Longo AV, Maneyro R, McDonald CA, Mendelson J, Palacios-Rodriguez P, Parra-Olea G, Richards-Zawacki CL, Rödel MO, Rovito SM, Soto-Azat C, Toledo LF, Voyles J, Weldon C, Whitfield SM, Wilkinson M, Zamudio KR, Canessa S. Response to Comment on "Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity". Science 2020; 367:367/6484/eaay2905. [PMID: 32193294 DOI: 10.1126/science.aay2905] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Accepted: 02/20/2020] [Indexed: 01/03/2023]
Abstract
Lambert et al question our retrospective and holistic epidemiological assessment of the role of chytridiomycosis in amphibian declines. Their alternative assessment is narrow and provides an incomplete evaluation of evidence. Adopting this approach limits understanding of infectious disease impacts and hampers conservation efforts. We reaffirm that our study provides unambiguous evidence that chytridiomycosis has affected at least 501 amphibian species.
Collapse
Affiliation(s)
- Ben C Scheele
- Fenner School of Environment and Society, Australian National University, Canberra, ACT 2601, Australia. .,National Environmental Science Programme, Threatened Species Recovery Hub, Canberra, ACT 2601, Australia.,One Health Research Group, Melbourne Veterinary School, University of Melbourne, Werribee, VIC 3030, Australia
| | - Frank Pasmans
- Wildlife Health Ghent, Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - Lee F Skerratt
- One Health Research Group, Melbourne Veterinary School, University of Melbourne, Werribee, VIC 3030, Australia
| | - Lee Berger
- One Health Research Group, Melbourne Veterinary School, University of Melbourne, Werribee, VIC 3030, Australia
| | - An Martel
- Wildlife Health Ghent, Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - Wouter Beukema
- Wildlife Health Ghent, Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - Aldemar A Acevedo
- Programa de Doctorado en Ciencias Biológicas, Laboratorio de Biología Evolutiva, Pontificia Universidad Católica de Chile, Santiago, Chile.,Grupo de Investigación en Ecología y Biogeografía, Universidad de Pamplona, Barrio El Buque, Pamplona, Colombia
| | | | - Tamilie Carvalho
- Laboratório de História Natural de Anfíbios Brasileiros, Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
| | - Alessandro Catenazzi
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
| | | | - Matthew C Fisher
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK
| | - Sandra V Flechas
- Department of Biological Sciences, Universidad de los Andes, Bogotá, Colombia.,Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Sede Venado de Oro, Bogotá, Colombia
| | - Claire N Foster
- Fenner School of Environment and Society, Australian National University, Canberra, ACT 2601, Australia
| | - Patricia Frías-Álvarez
- One Health Research Group, Melbourne Veterinary School, University of Melbourne, Werribee, VIC 3030, Australia
| | - Trenton W J Garner
- Institute of Zoology, Zoological Society London, Regents Park, London NW1 4RY, UK.,Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa
| | - Brian Gratwicke
- Smithsonian National Zoological Park and Conservation Biology Institute, Washington, DC 20008, USA
| | - Juan M Guayasamin
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Instituto de Investigaciones Biológicas y Ambientales BIOSFERA, Laboratorio de Biología Evolutiva, Campus Cumbayá, Quito, Ecuador.,Centro de Investigación de la Biodiversidad y Cambio Climático (BioCamb), Ingeniería en Biodiversidad y Cambio Climático, Facultad de Medio Ambiente, Universidad Tecnológica Indoamérica, Calle Machala y Sabanilla, Quito, Ecuador.,Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Mareike Hirschfeld
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Berlin 10115, Germany
| | - Jonathan E Kolby
- One Health Research Group, Melbourne Veterinary School, University of Melbourne, Werribee, VIC 3030, Australia.,Honduras Amphibian Rescue and Conservation Center, Lancetilla Botanical Garden and Research Center, Tela, Honduras.,The Conservation Agency, Jamestown, RI 02835, USA
| | - Tiffany A Kosch
- One Health Research Group, Melbourne Veterinary School, University of Melbourne, Werribee, VIC 3030, Australia.,AL Rae Centre for Genetics and Breeding, Massey University, Palmerston North 4442, New Zealand
| | - Enrique La Marca
- School of Geography, Faculty of Forestry Engineering and Environmental Sciences, University of Los Andes, Merida, Venezuela
| | - David B Lindenmayer
- Fenner School of Environment and Society, Australian National University, Canberra, ACT 2601, Australia.,National Environmental Science Programme, Threatened Species Recovery Hub, Canberra, ACT 2601, Australia
| | - Karen R Lips
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Ana V Longo
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Raúl Maneyro
- Laboratorio de Sistemática e Historia Natural de Vertebrados, Facultad de Ciencias, Universidad de la República, CP 11400 Montevideo, Uruguay
| | - Cait A McDonald
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Joseph Mendelson
- Zoo Atlanta, Atlanta, GA 30315, USA.,School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | | | - Gabriela Parra-Olea
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico City, México
| | | | - Mark-Oliver Rödel
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Berlin 10115, Germany
| | - Sean M Rovito
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Irapuato, Guanajuato CP36824, México
| | - Claudio Soto-Azat
- Centro de Investigación para la Sustentabilidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370251, Chile
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros, Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
| | - Jamie Voyles
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Ché Weldon
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa
| | - Steven M Whitfield
- Conservation and Research Department, Zoo Miami, Miami, FL 33177, USA.,School of Earth, Environment, and Society, Florida International University, Miami, FL 33199, USA
| | - Mark Wilkinson
- Department of Life Sciences, Natural History Museum, London SW7 5BD, UK
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Stefano Canessa
- Wildlife Health Ghent, Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| |
Collapse
|
16
|
Longo AV, Rodríguez‐Gómez CA, Zegarra JP, Monzón O, Claudio‐Hernández HJ, Joglar RL, Zamudio KR, Burrowes PA, López‐Torres AL. Tick parasitism as a cost of sexual selection and male parental care in a Neotropical frog. Ecosphere 2020. [DOI: 10.1002/ecs2.3010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Ana V. Longo
- Department of Biology University of Florida P.O. Box 118525 Gainesville Florida 32605 USA
| | - Carlos A. Rodríguez‐Gómez
- Proyecto Coquí 120 La Sierra #132 San Juan 00926 Puerto Rico
- Para La Naturaleza P.O. Box 9023554 San Juan 00902‐3554 Puerto Rico
| | - Jan P. Zegarra
- Caribbean Ecological Services Field Office U.S. Fish and Wildlife Service P.O. Box 491 Boquerón 00622 Puerto Rico
| | - Omar Monzón
- Para La Naturaleza P.O. Box 9023554 San Juan 00902‐3554 Puerto Rico
| | | | - Rafael L. Joglar
- Proyecto Coquí 120 La Sierra #132 San Juan 00926 Puerto Rico
- Department of Biology University of Puerto Rico P.O. Box 23360 San Juan 00931‐3360 Puerto Rico
| | - Kelly R. Zamudio
- Department of Ecology and Evolutionary Biology Cornell University E145 Corson Hall Ithaca New York 14853 USA
| | - Patricia A. Burrowes
- Department of Biology University of Puerto Rico P.O. Box 23360 San Juan 00931‐3360 Puerto Rico
| | | |
Collapse
|
17
|
Ossiboff RJ, Towe AE, Brown MA, Longo AV, Lips KR, Miller DL, Carter ED, Gray MJ, Frasca S. Differentiating Batrachochytrium dendrobatidis and B. salamandrivorans in Amphibian Chytridiomycosis Using RNAScope ® in situ Hybridization. Front Vet Sci 2019; 6:304. [PMID: 31572738 PMCID: PMC6751264 DOI: 10.3389/fvets.2019.00304] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Accepted: 08/28/2019] [Indexed: 12/25/2022] Open
Abstract
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 detection methods for these fungi are well-characterized, differentiation of the morphologically similar organisms in the tissues of affected amphibians is incredibly difficult. Moreover, an accurate tool to identify and differentiate Batrachochytrium in affected amphibian tissues is essential for a specific diagnosis of the causative agent in chytridiomycosis cases. To address this need, an automated dual-plex chromogenic RNAScope®in situ hybridization (ISH) assay was developed and characterized for simultaneous detection and differentiation of B. dendrobatidis and B. salamandrivorans. The assay, utilizing double Z target probe pairs designed to hybridize to 28S rRNA sequences, was specific for the identification of both organisms in culture and in formalin-fixed paraffin-embedded amphibian tissues. The assay successfully identified organisms in tissue samples from five salamander and one frog species preserved in formalin for up to 364 days and was sensitive for the detection of Batrachochytrium in animals with qPCR loads as low as 1.1 × 102 zoospores/microliter. ISH staining of B. salamandrivorans also highlighted the infection of dermal cutaneous glands, a feature not observed in amphibian B. dendrobatidis cases and which may play an important role in B. salamandrivorans pathogenesis in salamanders. The developed ISH assay will benefit both amphibian chytridiomycosis surveillance projects and pathogenesis studies by providing a reliable tool for Batrachochytrium differentiation in tissues.
Collapse
Affiliation(s)
- Robert J Ossiboff
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Anastasia E Towe
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Knoxville, TN, United States
| | - Melissa A Brown
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| | - Ana V Longo
- Department of Biology, University of Florida, Gainesville, FL, United States.,Department of Biology, University of Maryland College Park, College Park, MD, United States
| | - Karen R Lips
- Department of Biology, University of Maryland College Park, College Park, MD, United States
| | - Debra L Miller
- Department of Biomedical and Diagnostic Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, Knoxville, TN, United States.,Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, TN, United States
| | - E Davis Carter
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, TN, United States
| | - Matthew J Gray
- Center for Wildlife Health, University of Tennessee Institute of Agriculture, Knoxville, TN, United States
| | - Salvatore Frasca
- Department of Comparative, Diagnostic, and Population Medicine, College of Veterinary Medicine, University of Florida, Gainesville, FL, United States
| |
Collapse
|
18
|
Scheele BC, Pasmans F, Skerratt LF, Berger L, Martel A, Beukema W, Acevedo AA, Burrowes PA, Carvalho T, Catenazzi A, De la Riva I, Fisher MC, Flechas SV, Foster CN, Frías-Álvarez P, Garner TWJ, Gratwicke B, Guayasamin JM, Hirschfeld M, Kolby JE, Kosch TA, La Marca E, Lindenmayer DB, Lips KR, Longo AV, Maneyro R, McDonald CA, Mendelson J, Palacios-Rodriguez P, Parra-Olea G, Richards-Zawacki CL, Rödel MO, Rovito SM, Soto-Azat C, Toledo LF, Voyles J, Weldon C, Whitfield SM, Wilkinson M, Zamudio KR, Canessa S. Amphibian fungal panzootic causes catastrophic and ongoing loss of biodiversity. Science 2019; 363:1459-1463. [PMID: 30923224 DOI: 10.1126/science.aav0379] [Citation(s) in RCA: 531] [Impact Index Per Article: 106.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 02/06/2019] [Indexed: 12/18/2022]
Abstract
Anthropogenic trade and development have broken down dispersal barriers, facilitating the spread of diseases that threaten Earth's biodiversity. We present a global, quantitative assessment of the amphibian chytridiomycosis panzootic, one of the most impactful examples of disease spread, and demonstrate its role in the decline of at least 501 amphibian species over the past half-century, including 90 presumed extinctions. The effects of chytridiomycosis have been greatest in large-bodied, range-restricted anurans in wet climates in the Americas and Australia. Declines peaked in the 1980s, and only 12% of declined species show signs of recovery, whereas 39% are experiencing ongoing decline. There is risk of further chytridiomycosis outbreaks in new areas. The chytridiomycosis panzootic represents the greatest recorded loss of biodiversity attributable to a disease.
Collapse
Affiliation(s)
- Ben C Scheele
- Fenner School of Environment and Society, Australian National University, Canberra, ACT 2601, Australia. .,National Environmental Science Programme, Threatened Species Recovery Hub, Canberra, ACT 2601, Australia.,One Health Research Group, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia
| | - Frank Pasmans
- Wildlife Health Ghent, Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - Lee F Skerratt
- One Health Research Group, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia
| | - Lee Berger
- One Health Research Group, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia
| | - An Martel
- Wildlife Health Ghent, Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - Wouter Beukema
- Wildlife Health Ghent, Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| | - Aldemar A Acevedo
- Programa de Doctorado en Ciencias Biológicas, Laboratorio de Biología Evolutiva, Pontificia Universidad Católica de Chile, Avenida Libertador Bernardo O'Higgins 340, Santiago, Chile.,Grupo de Investigación en Ecología y Biogeografía, Universidad de Pamplona, Barrio El Buque, Km 1, Vía a Bucaramanga, Pamplona, Colombia
| | - Patricia A Burrowes
- Department of Biology, University of Puerto Rico, P.O. Box 23360, San Juan, Puerto Rico
| | - Tamilie Carvalho
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
| | - Alessandro Catenazzi
- Department of Biological Sciences, Florida International University, Miami, FL 33199, USA
| | - Ignacio De la Riva
- Museo Nacional de Ciencias Naturales-CSIC, C/ José Gutiérrez Abascal 2, Madrid 28006, Spain
| | - Matthew C Fisher
- MRC Centre for Global Infectious Disease Analysis, School of Public Health, Imperial College London, London W2 1PG, UK
| | - Sandra V Flechas
- Department of Biological Sciences, Universidad de los Andes, Bogotá, Colombia.,Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Sede Venado de Oro, Paseo Bolívar 16-20, Bogotá, Colombia
| | - Claire N Foster
- Fenner School of Environment and Society, Australian National University, Canberra, ACT 2601, Australia
| | - Patricia Frías-Álvarez
- One Health Research Group, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia
| | - Trenton W J Garner
- Institute of Zoology, Zoological Society London, Regents Park, London NW1 4RY, UK.,Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa
| | - Brian Gratwicke
- Smithsonian National Zoological Park and Conservation Biology Institute, Washington, DC 20008, USA
| | - Juan M Guayasamin
- Universidad San Francisco de Quito USFQ, Colegio de Ciencias Biológicas y Ambientales COCIBA, Instituto de Investigaciones Biológicas y Ambientales BIOSFERA, Laboratorio de Biología Evolutiva, Campus Cumbayá, Quito, Ecuador.,Centro de Investigación de la Biodiversidad y Cambio Climático (BioCamb), Ingeniería en Biodiversidad y Cambio Climático, Facultad de Medio Ambiente, Universidad Tecnológica Indoamérica, Calle Machala y Sabanilla, Quito, Ecuador.,Department of Biology, Colorado State University, Fort Collins, CO 80523, USA
| | - Mareike Hirschfeld
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstr. 43, Berlin 10115, Germany
| | - Jonathan E Kolby
- One Health Research Group, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia.,Honduras Amphibian Rescue and Conservation Center, Lancetilla Botanical Garden and Research Center, Tela, Honduras.,The Conservation Agency, Jamestown, RI 02835, USA
| | - Tiffany A Kosch
- One Health Research Group, Melbourne Veterinary School, The University of Melbourne, Werribee, VIC 3030, Australia.,AL Rae Centre for Genetics and Breeding, Massey University, Palmerston North 4442, New Zealand
| | - Enrique La Marca
- School of Geography, Faculty of Forestry Engineering and Environmental Sciences, University of Los Andes, Merida, Venezuela
| | - David B Lindenmayer
- Fenner School of Environment and Society, Australian National University, Canberra, ACT 2601, Australia.,National Environmental Science Programme, Threatened Species Recovery Hub, Canberra, ACT 2601, Australia
| | - Karen R Lips
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - Ana V Longo
- Department of Biology, University of Florida, Gainesville, FL 32611, USA
| | - Raúl Maneyro
- Laboratorio de Sistemática e Historia Natural de Vertebrados. Facultad de Ciencias, Universidad de la República. Igua 4225, CP 11400, Montevideo, Uruguay
| | - Cait A McDonald
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Joseph Mendelson
- Zoo Atlanta, Atlanta, GA 30315, USA.,School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | | | - Gabriela Parra-Olea
- Departamento de Zoología, Instituto de Biología, Universidad Nacional Autónoma de México, Mexico City, México
| | | | - Mark-Oliver Rödel
- Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstr. 43, Berlin 10115, Germany
| | - Sean M Rovito
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, km 9.6 Libramiento Norte Carretera Irapuato-León, Irapuato, Guanajuato CP36824, México
| | - Claudio Soto-Azat
- Centro de Investigación para la Sustentabilidad, Facultad de Ciencias de la Vida, Universidad Andres Bello, Santiago 8370251, Chile
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, Brazil
| | - Jamie Voyles
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Ché Weldon
- Unit for Environmental Sciences and Management, North-West University, Potchefstroom 2520, South Africa
| | - Steven M Whitfield
- Zoo Miami, Conservation and Research Department, Miami, FL 33177, USA.,Florida International University School of Earth, Environment, and Society, 11200 SW 8th St., Miami, FL 33199, USA
| | - Mark Wilkinson
- Department of Life Sciences, The Natural History Museum, London SW7 5BD, UK
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Stefano Canessa
- Wildlife Health Ghent, Department of Pathology, Bacteriology, and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, B-9820 Merelbeke, Belgium
| |
Collapse
|
19
|
|
20
|
Kueneman JG, Bletz MC, McKenzie VJ, Becker CG, Joseph MB, Abarca JG, Archer H, Arellano AL, Bataille A, Becker M, Belden LK, Crottini A, Geffers R, Haddad CFB, Harris RN, Holden WM, Hughey M, Jarek M, Kearns PJ, Kerby JL, Kielgast J, Kurabayashi A, Longo AV, Loudon A, Medina D, Nuñez JJ, Perl RGB, Pinto-Tomás A, Rabemananjara FCE, Rebollar EA, Rodríguez A, Rollins-Smith L, Stevenson R, Tebbe CC, Vargas Asensio G, Waldman B, Walke JB, Whitfield SM, Zamudio KR, Zúñiga Chaves I, Woodhams DC, Vences M. Community richness of amphibian skin bacteria correlates with bioclimate at the global scale. Nat Ecol Evol 2019; 3:381-389. [DOI: 10.1038/s41559-019-0798-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 01/06/2019] [Indexed: 12/15/2022]
|
21
|
DiRenzo GV, Zipkin EF, Grant EHC, Royle JA, Longo AV, Zamudio KR, Lips KR. Eco-evolutionary rescue promotes host-pathogen coexistence. Ecol Appl 2018; 28:1948-1962. [PMID: 30368999 DOI: 10.1002/eap.1792] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Revised: 09/12/2018] [Accepted: 06/22/2018] [Indexed: 06/08/2023]
Abstract
Emerging infectious pathogens are responsible for some of the most severe host mass mortality events in wild populations. Yet, effective pathogen control strategies are notoriously difficult to identify, in part because quantifying and forecasting pathogen spread and disease dynamics is challenging. Following an outbreak, hosts must cope with the presence of the pathogen, leading to host-pathogen coexistence or extirpation. Despite decades of research, little is known about host-pathogen coexistence post-outbreak when low host abundances and cryptic species make these interactions difficult to study. Using a novel disease-structured N-mixture model, we evaluate empirical support for three host-pathogen coexistence hypotheses (source-sink, eco-evolutionary rescue, and spatial variation in pathogen transmission) in a Neotropical amphibian community decimated by Batrachochytrium dendrobatidis (Bd) in 2004. During 2010-2014, we surveyed amphibians in Parque Nacional G. D. Omar Torríjos Herrera, Coclé Province, El Copé, Panama. We found that the primary driver of host-pathogen coexistence was eco-evolutionary rescue, as evidenced by similar amphibian survival and recruitment rates between infected and uninfected hosts. Average apparent monthly survival rates of uninfected and infected hosts were both close to 96%, and the expected number of uninfected and infected hosts recruited (via immigration/reproduction) was less than one host per disease state per 20-m site. The secondary driver of host-pathogen coexistence was spatial variation in pathogen transmission as we found that transmission was highest in areas of low abundance but there was no support for the source-sink hypothesis. Our results indicate that changes in the host community (i.e., through genetic or species composition) can reduce the impacts of emerging infectious disease post-outbreak. Our disease-structured N-mixture model represents a valuable advancement for conservation managers trying to understand underlying host-pathogen interactions and provides new opportunities to study disease dynamics in remnant host populations decimated by virulent pathogens.
Collapse
Affiliation(s)
- Graziella V DiRenzo
- Department of Biology, University of Maryland, College Park, Maryland, 20744, USA
- Department of Integrative Biology and Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Elise F Zipkin
- Department of Integrative Biology and Ecology, Evolutionary Biology, and Behavior Program, Michigan State University, East Lansing, Michigan, 48824, USA
| | - Evan H Campbell Grant
- U.S. Geological Survey, Patuxent Wildlife Research Center, SO Conte Anadromous Fish Research Lab, Turners Falls, Massachusetts, 01376, USA
| | - J Andrew Royle
- U.S. Geological Survey, Patuxent Wildlife Research Center, Laurel, Maryland, 20708-4017, USA
| | - Ana V Longo
- Department of Biology, University of Maryland, College Park, Maryland, 20744, USA
| | - Kelly R Zamudio
- Department of Ecology & Evolutionary Biology, Cornell University, Ithaca, New York, 14583, USA
| | - Karen R Lips
- Department of Biology, University of Maryland, College Park, Maryland, 20744, USA
| |
Collapse
|
22
|
DiRenzo GV, Tunstall TS, Ibáñez R, deVries MS, Longo AV, Zamudio KR, Lips KR. External Reinfection of a Fungal Pathogen Does not Contribute to Pathogen Growth. Ecohealth 2018; 15:815-826. [PMID: 30128614 DOI: 10.1007/s10393-018-1358-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 06/23/2018] [Accepted: 07/05/2018] [Indexed: 06/08/2023]
Abstract
Chytridiomycosis is an emerging infectious disease of amphibians caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), which has led to devastating declines in amphibian populations worldwide. Current theory predicts that Bd infections are maintained through both reproduction on the host's skin and reinfection from sources outside of the host. To investigate the importance of external reinfection on pathogen burden, we infected captive-bred individuals of the highly susceptible Panamanian Golden Frog, Atelopus glyphus, and wild-caught glass frogs, Espadarana prosoblepon, with Bd. We housed the animals in one of three treatments: individually, in heterospecific pairs, and in conspecific pairs. For 8 weeks, we measured the Bd load and shedding rate of all frogs. We found that Atelopus had high rates of increase in both Bd load and shedding rate, but pathogen growth rates did not differ among treatments. The infection intensity of Espadarana co-housed with Atelopus was indistinguishable from those housed singly and those in conspecific pairs, despite being exposed to a large external source of Bd zoospores. Our results indicate that Bd load in both species is driven by pathogen replication within an individual, with reinfection from outside the host contributing little to the amplification of host fungal load.
Collapse
Affiliation(s)
- Graziella V DiRenzo
- Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, 93106, USA
| | - Tate S Tunstall
- Institute for Conservation Research, San Diego Zoo, San Diego, CA, 92027, USA.
| | - Roberto Ibáñez
- Smithsonian Tropical Research Institute, Panama City, Panama
| | - Maya S deVries
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, 92037, USA
| | - Ana V Longo
- Department of Biology, University of Maryland, College Park, College Park, MD, 20742, USA
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 1458, USA
| | - Karen R Lips
- Department of Biology, University of Maryland, College Park, College Park, MD, 20742, USA
| |
Collapse
|
23
|
Becker CG, Longo AV, Haddad CFB, Zamudio KR. Land cover and forest connectivity alter the interactions among host, pathogen and skin microbiome. Proc Biol Sci 2018; 284:rspb.2017.0582. [PMID: 28835551 DOI: 10.1098/rspb.2017.0582] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Accepted: 07/14/2017] [Indexed: 12/11/2022] Open
Abstract
Deforestation has detrimental consequences on biodiversity, affecting species interactions at multiple scales. The associations among vertebrates, pathogens and their commensal/symbiotic microbial communities (i.e. microbiomes) have important downstream effects for biodiversity conservation, yet we know little about how deforestation contributes to changes in host microbial diversity and pathogen abundance. Here, we tested the effects of landcover, forest connectivity and infection by the chytrid fungus Batrachochytrium dendrobatidis (Bd) on amphibian skin bacterial diversity along deforestation gradients in Brazilian landscapes. If disturbance to natural habitat alters skin microbiomes as it does in vertebrate host communities, then we would expect higher host bacterial diversity in natural forest habitats. Bd infection loads are also often higher in these closed-canopy forests, which may in turn impact skin-associated bacterial communities. We found that forest corridors shaped composition of host skin microbiomes; high forest connectivity predicted greater similarity of skin bacterial communities among host populations. In addition, we found that host skin bacterial diversity and Bd loads increased towards natural vegetation. Because symbiotic bacteria can potentially buffer hosts from Bd infection, we also evaluated the bi-directional microbiome-Bd link but failed to find a significant effect of skin bacterial diversity reducing Bd infections. Although weak, we found support for Bd increasing bacterial diversity and/or for core bacteria dominance reducing Bd loads. Our research incorporates a critical element in the study of host microbiomes by linking environmental heterogeneity of landscapes to the host-pathogen-microbiome triangle.
Collapse
Affiliation(s)
- C G Becker
- Universidade Estadual Paulista, Instituto de Biociências, Departamento de Zoologia and Centro de Aquicultura (CAUNESP), 13506-900 Rio Claro, SP, Brazil
| | - A V Longo
- Department of Biology, University of Maryland, College Park, MD 20742, USA
| | - C F B Haddad
- Universidade Estadual Paulista, Instituto de Biociências, Departamento de Zoologia and Centro de Aquicultura (CAUNESP), 13506-900 Rio Claro, SP, Brazil
| | - K R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
24
|
DiRenzo GV, Campbell Grant EH, Longo AV, Che‐Castaldo C, Zamudio KR, Lips KR. Imperfect pathogen detection from non‐invasive skin swabs biases disease inference. Methods Ecol Evol 2017. [DOI: 10.1111/2041-210x.12868] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Evan H. Campbell Grant
- U.S. Geological Survey Patuxent Wildlife Research Center SO Conte Anadromous Fish Research Lab Turners Falls MA USA
| | - Ana V. Longo
- Department of Biology University of Maryland College Park MD USA
| | | | - Kelly R. Zamudio
- Department of Ecology & Evolutionary Biology Cornell University Ithaca NY USA
| | - Karen R. Lips
- Department of Biology University of Maryland College Park MD USA
| |
Collapse
|
25
|
Hydeman ME, Longo AV, Velo-Antón G, Rodriguez D, Zamudio KR, Bell RC. Prevalence and genetic diversity of Batrachochytrium dendrobatidis in Central African island and continental amphibian communities. Ecol Evol 2017; 7:7729-7738. [PMID: 29043029 PMCID: PMC5632636 DOI: 10.1002/ece3.3309] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2017] [Revised: 07/07/2017] [Accepted: 07/12/2017] [Indexed: 01/14/2023] Open
Abstract
The fungal pathogen Batrachochytrium dendrobatidis (Bd) infects hundreds of amphibian species and is implicated in global amphibian declines. Bd is comprised of several lineages that differ in pathogenicity, thus, identifying which Bd strains are present in a given amphibian community is essential for understanding host–pathogen dynamics. The presence of Bd has been confirmed in Central Africa, yet vast expanses of this region have not yet been surveyed for Bd prevalence, and the genetic diversity of Bd is largely unknown in this part of the world. Using retrospective surveys of museum specimens and contemporary field surveys, we estimated the prevalence of Bd in Central African island and continental amphibian assemblages, and genotyped strains of Bd present in each community. Our sampling of museum specimens included just a few individuals collected in the Gulf of Guinea archipelago prior to 1998, yet one of these individuals was Bd‐positive indicating that the pathogen has been on Bioko Island since 1966. We detected Bd across all subsequent sample years in our study and found modest support for a relationship between host life history and Bd prevalence, a positive relationship between prevalence and host community species richness, and no significant relationship between elevation and prevalence. The Global Panzootic Lineage (BdGPL) was present in all the island and continental amphibian communities we surveyed. Our results are consistent with a long‐term and widespread distribution of Bd in amphibian communities of Gabon and the Gulf of Guinea archipelago.
Collapse
Affiliation(s)
- Marina E Hydeman
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY USA
| | - Ana V Longo
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY USA
| | - Guillermo Velo-Antón
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY USA.,CIBIO-InBIO Universidade do Porto Campus Agrário de Vairão Vairão Portugal
| | - David Rodriguez
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY USA.,Department of Biology Texas State University San Marcos TX USA
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY USA
| | - Rayna C Bell
- Department of Ecology and Evolutionary Biology Cornell University Ithaca NY USA.,Department of Vertebrate Zoology National Museum of Natural History Smithsonian Institution Washington DC USA
| |
Collapse
|
26
|
Longo AV, Zamudio KR. Temperature variation, bacterial diversity and fungal infection dynamics in the amphibian skin. Mol Ecol 2017; 26:4787-4797. [PMID: 28664981 DOI: 10.1111/mec.14220] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 06/02/2017] [Accepted: 06/12/2017] [Indexed: 12/23/2022]
Abstract
Host-associated bacterial communities on the skin act as the first line of defence against invading pathogens. Yet, for most natural systems, we lack a clear understanding of how temperature variability affects structure and composition of skin bacterial communities and, in turn, promotes or limits the colonization of opportunistic pathogens. Here, we examine how natural temperature fluctuations might be related to changes in skin bacterial diversity over time in three amphibian populations infected by the pathogenic fungus Batrachochytrium dendrobatidis (Bd). Our focal host species (Eleutherodactylus coqui) is a direct-developing frog that has suffered declines at some populations in the last 20 years, while others have not experienced any changes. We quantified skin bacterial alpha- and beta-diversity at four sampling time points, a period encompassing two seasons and ample variation in natural infections and environmental conditions. Despite the different patterns of infection across populations, we detected an overall increase in bacterial diversity through time, characterized by the replacement of bacterial operational taxonomic units (OTUs). Increased frog body temperatures possibly allowed the colonization of bacteria as well as the recruitment of a subset of indicator OTUs, which could have promoted the observed changes in diversity patterns. Our results suggest that natural environmental fluctuations might be involved in creating opportunities for bacterial replacement, potentially attenuating pathogen transmission and thus contributing to host persistence in E. coqui populations.
Collapse
Affiliation(s)
- Ana V Longo
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| |
Collapse
|
27
|
Burrowes PA, Martes MC, Torres-Ríos M, Longo AV. Arboreality predicts Batrachochytrium dendrobatidis infection level in tropical direct-developing frogs. J NAT HIST 2017. [DOI: 10.1080/00222933.2017.1297504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
28
|
Longo AV, Zamudio KR. Environmental fluctuations and host skin bacteria shift survival advantage between frogs and their fungal pathogen. ISME J 2016; 11:349-361. [PMID: 27935596 DOI: 10.1038/ismej.2016.138] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/08/2016] [Accepted: 08/15/2016] [Indexed: 12/11/2022]
Abstract
Fluctuating environments can modulate host-pathogen interactions by providing a temporary advantage to one of the interacting organisms. However, we know very little about how environmental conditions facilitate beneficial interactions between hosts and their microbial communities, resulting in individual persistence with a particular pathogen. Here, we experimentally infected Eleutherodactylus coqui frogs with the fungal pathogen Batrachochytrium dendrobatidis (Bd) under environmental conditions known to confer the survival advantage to the host during the warm-wet season, or alternatively to the pathogen during the cool-dry season. We used 16S rRNA amplicon sequencing to quantify changes in bacterial richness and phylogenetic diversity, and identified operational taxonomic units (OTUs) that became overrepresented or suppressed as a consequence of Bd infection. During the warm-wet season, frogs limited Bd infections, recruited putatively beneficial bacteria and returned to pre-infection levels of richness and phylogenetic diversity. In contrast, during the cool-dry season, Bd infections kept increasing through time, and bacterial diversity remained constant. Our findings confirm that infection outcome not only depends on abiotic factors, but also on biotic interactions between hosts and their associated bacterial communities.
Collapse
Affiliation(s)
- Ana V Longo
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
29
|
Bovo RP, Andrade DV, Toledo LF, Longo AV, Rodriguez D, Haddad CFB, Zamudio KR, Becker CG. Physiological responses of Brazilian amphibians to an enzootic infection of the chytrid fungus Batrachochytrium dendrobatidis. Dis Aquat Organ 2016; 117:245-52. [PMID: 26758658 DOI: 10.3354/dao02940] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Pathophysiological effects of clinical chytridiomycosis in amphibians include disorders of cutaneous osmoregulation and disruption of the ability to rehydrate, which can lead to decreased host fitness or mortality. Less attention has been given to physiological responses of hosts where enzootic infections of Batrachochytrium dendrobatidis (Bd) do not cause apparent population declines in the wild. Here, we experimentally tested whether an enzootic strain of Bd causes significant mortality and alters host water balance (evaporative water loss, EWL; skin resistance, R(s); and water uptake, WU) in individuals of 3 Brazilian amphibian species (Dendropsophus minutus, n = 19; Ischnocnema parva, n = 17; Brachycephalus pitanga, n = 15). Infections with enzootic Bd caused no significant mortality, but we found an increase in R(s) in 1 host species concomitant with a reduction in EWL. These results suggest that enzootic Bd infections can indeed cause sub-lethal effects that could lead to reduction of host fitness in Brazilian frogs and that these effects vary among species. Thus, our findings underscore the need for further assessment of physiological responses to Bd infections in different host species, even in cases of sub-clinical chytridiomycosis and long-term enzootic infections in natural populations.
Collapse
Affiliation(s)
- Rafael P Bovo
- Departamento de Zoologia, c. p. 199, Universidade Estadual Paulista, 13506-900, Rio Claro, SP, Brazil
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Becker CG, Rodriguez D, Toledo LF, Longo AV, Lambertini C, Corrêa DT, Leite DS, Haddad CFB, Zamudio KR. Partitioning the net effect of host diversity on an emerging amphibian pathogen. Proc Biol Sci 2015; 281:rspb.2014.1796. [PMID: 25297867 DOI: 10.1098/rspb.2014.1796] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The 'dilution effect' (DE) hypothesis predicts that diverse host communities will show reduced disease. The underlying causes of pathogen dilution are complex, because they involve non-additive (driven by host interactions and differential habitat use) and additive (controlled by host species composition) mechanisms. Here, we used measures of complementarity and selection traditionally employed in the field of biodiversity-ecosystem function (BEF) to quantify the net effect of host diversity on disease dynamics of the amphibian-killing fungus Batrachochytrium dendrobatidis (Bd). Complementarity occurs when average infection load in diverse host assemblages departs from that of each component species in uniform populations. Selection measures the disproportionate impact of a particular species in diverse assemblages compared with its performance in uniform populations, and therefore has strong additive and non-additive properties. We experimentally infected tropical amphibian species of varying life histories, in single- and multi-host treatments, and measured individual Bd infection loads. Host diversity reduced Bd infection in amphibians through a mechanism analogous to complementarity (sensu BEF), potentially by reducing shared habitat use and transmission among hosts. Additionally, the selection component indicated that one particular terrestrial species showed reduced infection loads in diverse assemblages at the expense of neighbouring aquatic hosts becoming heavily infected. By partitioning components of diversity, our findings underscore the importance of additive and non-additive mechanisms underlying the DE.
Collapse
Affiliation(s)
- C Guilherme Becker
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - David Rodriguez
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA Department of Agriculture, Texas State University, San Marcos, TX 78666, USA
| | - L Felipe Toledo
- Departamento de Biologia Animal, Universidade Estadual de Campinas, Campinas, São Paulo 13083-970, Brazil
| | - Ana V Longo
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| | - Carolina Lambertini
- Departamento de Biologia Animal, Universidade Estadual de Campinas, Campinas, São Paulo 13083-970, Brazil
| | - Décio T Corrêa
- Departamento de Biologia Animal, Universidade Estadual de Campinas, Campinas, São Paulo 13083-970, Brazil Department of Integrative Biology, The University of Texas at Austin, Austin, TX 78712, USA
| | - Domingos S Leite
- Departamento de Genética, Evolução e Bioagentes, Universidade Estadual de Campinas, Campinas, São Paulo 13083-970, Brazil
| | - Célio F B Haddad
- Departamento de Zoologia, Universidade Estadual Paulista, Rio Claro, São Paulo 13506-900, Brazil
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
31
|
James TY, Toledo LF, Rödder D, da Silva Leite D, Belasen AM, Betancourt-Román CM, Jenkinson TS, Soto-Azat C, Lambertini C, Longo AV, Ruggeri J, Collins JP, Burrowes PA, Lips KR, Zamudio KR, Longcore JE. Disentangling host, pathogen, and environmental determinants of a recently emerged wildlife disease: lessons from the first 15 years of amphibian chytridiomycosis research. Ecol Evol 2015; 5:4079-97. [PMID: 26445660 PMCID: PMC4588650 DOI: 10.1002/ece3.1672] [Citation(s) in RCA: 150] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2015] [Accepted: 07/25/2015] [Indexed: 12/18/2022] Open
Abstract
The amphibian fungal disease chytridiomycosis, which affects species across all continents, recently emerged as one of the greatest threats to biodiversity. Yet, many aspects of the basic biology and epidemiology of the pathogen, Batrachochytrium dendrobatidis (Bd), are still unknown, such as when and from where did Bd emerge and what is its true ecological niche? Here, we review the ecology and evolution of Bd in the Americas and highlight controversies that make this disease so enigmatic. We explore factors associated with variance in severity of epizootics focusing on the disease triangle of host susceptibility, pathogen virulence, and environment. Reevaluating the causes of the panzootic is timely given the wealth of data on Bd prevalence across hosts and communities and the recent discoveries suggesting co-evolutionary potential of hosts and Bd. We generate a new species distribution model for Bd in the Americas based on over 30,000 records and suggest a novel future research agenda. Instead of focusing on pathogen "hot spots," we need to identify pathogen "cold spots" so that we can better understand what limits the pathogen's distribution. Finally, we introduce the concept of "the Ghost of Epizootics Past" to discuss expected patterns in postepizootic host communities.
Collapse
Affiliation(s)
- Timothy Y James
- Department of Ecology and Evolutionary Biology University of Michigan Ann Arbor Michigan 48109
| | - L Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB) Departamento de Biologia Animal Instituto de Biologia Universidade Estadual de Campinas Caixa Postal 6109 Campinas São Paulo CEP 13083-863 Brazil
| | - Dennis Rödder
- Section of Herpetology Zoologisches Forschungsmuseum Alexander Koenig Adenauerallee 160 53113 Bonn Germany
| | - Domingos da Silva Leite
- Laboratório de Antígenos Bacterianos II Departamento de Genética, Evolução e Bioagentes Instituto de Biologia Universidade Estadual de Campinas Caixa Postal 6109 Campinas São Paulo CEP 13083-862 Brazil
| | - Anat M Belasen
- Department of Ecology and Evolutionary Biology University of Michigan Ann Arbor Michigan 48109
| | | | - Thomas S Jenkinson
- Department of Ecology and Evolutionary Biology University of Michigan Ann Arbor Michigan 48109
| | - Claudio Soto-Azat
- Centro de Investigación para la Sustentabilidad Facultad de Ecología y Recursos Naturales, Universidad Andres Bello Santiago Chile
| | - Carolina Lambertini
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB) Departamento de Biologia Animal Instituto de Biologia Universidade Estadual de Campinas Caixa Postal 6109 Campinas São Paulo CEP 13083-863 Brazil
| | - Ana V Longo
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York 14853
| | - Joice Ruggeri
- Departamento de Zoologia Laboratório de Anfíbios e Répteis Universidade Federal do Rio de Janeiro, Instituto de Biologia Ilha do Fundão, Caixa postal: 68044 Rio de Janeiro RJ CEP 21941-590 Brazil
| | - James P Collins
- School of Life Sciences Arizona State University PO Box 874501 Tempe Arizona 85287-4501
| | | | - Karen R Lips
- Department of Biology University of Maryland College Park Maryland 20901
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology Cornell University Ithaca New York 14853
| | - Joyce E Longcore
- School of Biology and Ecology University of Maine Orono Maine 04469-5722
| |
Collapse
|
32
|
Ruggeri J, Longo AV, Gaiarsa MP, Alencar LRV, Lambertini C, Leite DS, Carvalho-e-Silva SP, Zamudio KR, Toledo LF, Martins M. Seasonal Variation in Population Abundance and Chytrid Infection in Stream-Dwelling Frogs of the Brazilian Atlantic Forest. PLoS One 2015; 10:e0130554. [PMID: 26161777 PMCID: PMC4498819 DOI: 10.1371/journal.pone.0130554] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 05/22/2015] [Indexed: 11/18/2022] Open
Abstract
Enigmatic amphibian declines were first reported in southern and southeastern Brazil in the late 1980s and included several species of stream-dwelling anurans (families Hylodidae and Cycloramphidae). At that time, we were unaware of the amphibian-killing fungus Batrachochytrium dendrobatidis (Bd); therefore, pollution, habitat loss, fragmentation and unusual climatic events were hypothesized as primary causes of these declines. We now know that multiple lineages of Bd have infected amphibians of the Brazilian Atlantic forest for over a century, yet declines have not been associated specifically with Bd outbreaks. Because stream-dwelling anurans occupy an environmental hotspot ideal for disease transmission, we investigated temporal variation in population and infection dynamics of three stream-adapted species (Hylodes asper, H. phyllodes, and Cycloramphus boraceiensis) on the northern coast of São Paulo state, Brazil. We surveyed standardized transects along streams for four years, and show that fluctuations in the number of frogs correlate with specific climatic variables that also increase the likelihood of Bd infections. In addition, we found that Bd infection probability in C. boraceiensis, a nocturnal species, was significantly higher than in Hylodes spp., which are diurnal, suggesting that the nocturnal activity may either facilitate Bd zoospore transmission or increase susceptibility of hosts. Our findings indicate that, despite long-term persistence of Bd in Brazil, some hosts persist with seasonally variable infections, and thus future persistence in the face of climate change will depend on the relative effect of those changes on frog recruitment and pathogen proliferation.
Collapse
Affiliation(s)
- Joice Ruggeri
- Instituto de Biologia, Universidade Federal do Rio de Janeiro, Ilha do Fundão, Rio de Janeiro, Brazil
| | - Ana V. Longo
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, United States of America
| | - Marília P. Gaiarsa
- Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Laura R. V. Alencar
- Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| | - Carolina Lambertini
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Domingos S. Leite
- Laboratório de Antígenos Bacterianos, Departamento de Genética, Evolução e Bioagentes, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | | | - Kelly R. Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, United States of America
| | - Luís Felipe Toledo
- Laboratório de História Natural de Anfíbios Brasileiros (LaHNAB), Departamento de Biologia Animal, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo, Brazil
| | - Marcio Martins
- Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil
| |
Collapse
|
33
|
Longo AV, Savage AE, Hewson I, Zamudio KR. Seasonal and ontogenetic variation of skin microbial communities and relationships to natural disease dynamics in declining amphibians. R Soc Open Sci 2015; 2:140377. [PMID: 26587253 PMCID: PMC4632566 DOI: 10.1098/rsos.140377] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 06/18/2015] [Indexed: 05/09/2023]
Abstract
Recently, microbiologists have focused on characterizing the probiotic role of skin bacteria for amphibians threatened by the fungal disease chytridiomycosis. However, the specific characteristics of microbial diversity required to maintain health or trigger disease are still not well understood in natural populations. We hypothesized that seasonal and developmental transitions affecting susceptibility to chytridiomycosis could also alter the stability of microbial assemblages. To test our hypothesis, we examined patterns of skin bacterial diversity in two species of declining amphibians (Lithobates yavapaiensis and Eleutherodactylus coqui) affected by the pathogenic fungus Batrachochytrium dendrobatidis (Bd). We focused on two important transitions that affect Bd susceptibility: ontogenetic (from juvenile to adult) shifts in E. coqui and seasonal (from summer to winter) shifts in L. yavapaiensis. We used a combination of community-fingerprinting analyses and 16S rRNA amplicon sequencing to quantify changes in bacterial diversity and assemblage composition between seasons and developmental stages, and to investigate the relationship between bacterial diversity and pathogen load. We found that winter-sampled frogs and juveniles, two states associated with increased Bd susceptibility, exhibited higher diversity compared with summer-sampled frogs and adult individuals. Our findings also revealed that hosts harbouring higher bacterial diversity carried lower Bd infections, providing support for the protective role of bacterial communities. Ongoing work to understand skin microbiome resilience after pathogen disturbance has the potential to identify key taxa involved in disease resistance.
Collapse
Affiliation(s)
- Ana V. Longo
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
- Author for correspondence: Ana V. Longo e-mail:
| | - Anna E. Savage
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
- Department of Biology, University of Central Florida, Orlando, FL 32816, USA
| | - Ian Hewson
- Department of Microbiology, Cornell University, Ithaca, NY 14853, USA
| | - Kelly R. Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA
| |
Collapse
|
34
|
Yuan ML, Dean SH, Longo AV, Rothermel BB, Tuberville TD, Zamudio KR. Kinship, inbreeding and fine-scale spatial structure influence gut microbiota in a hindgut-fermenting tortoise. Mol Ecol 2015; 24:2521-36. [PMID: 25809385 DOI: 10.1111/mec.13169] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 03/11/2015] [Accepted: 03/19/2015] [Indexed: 12/12/2022]
Abstract
Herbivorous vertebrates rely on complex communities of mutualistic gut bacteria to facilitate the digestion of celluloses and hemicelluloses. Gut microbes are often convergent based on diet and gut morphology across a phylogenetically diverse group of mammals. However, little is known about microbial communities of herbivorous hindgut-fermenting reptiles. Here, we investigate how factors at the individual level might constrain the composition of gut microbes in an obligate herbivorous reptile. Using multiplexed 16S rRNA gene sequencing, we characterized the faecal microbial community of a population of gopher tortoises (Gopherus polyphemus) and examined how age, genetic diversity, spatial structure and kinship influence differences among individuals. We recovered phylotypes associated with known cellulolytic function, including candidate phylum Termite Group 3, suggesting their importance for gopher tortoise digestion. Although host genetic structure did not explain variation in microbial composition and community structure, we found that fine-scale spatial structure, inbreeding, degree of relatedness and possibly ontogeny shaped patterns of diversity in faecal microbiomes of gopher tortoises. Our findings corroborate widespread convergence of faecal-associated microbes based on gut morphology and diet and demonstrate the role of spatial and demographic structure in driving differentiation of gut microbiota in natural populations.
Collapse
Affiliation(s)
- Michael L Yuan
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853-2701, USA; Archbold Biological Station, Venus, FL, 33960, USA
| | | | | | | | | | | |
Collapse
|
35
|
Longo AV, Rodriguez D, da Silva Leite D, Toledo LF, Mendoza Almeralla C, Burrowes PA, Zamudio KR. ITS1 copy number varies among Batrachochytrium dendrobatidis strains: implications for qPCR estimates of infection intensity from field-collected amphibian skin swabs. PLoS One 2013; 8:e59499. [PMID: 23555682 PMCID: PMC3605245 DOI: 10.1371/journal.pone.0059499] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2012] [Accepted: 02/14/2013] [Indexed: 12/02/2022] Open
Abstract
Genomic studies of the amphibian-killing fungus (Batrachochytrium dendrobatidis, [Bd]) identified three highly divergent genetic lineages, only one of which has a global distribution. Bd strains within these linages show variable genomic content due to differential loss of heterozygosity and recombination. The current quantitative polymerase chain reaction (qPCR) protocol to detect the fungus from amphibian skin swabs targets the intergenic transcribed spacer 1 (ITS1) region using a TaqMan fluorescent probe specific to Bd. We investigated the consequences of genomic differences in the quantification of ITS1 from eight distinct Bd strains, including representatives from North America, South America, the Caribbean, and Australia. To test for potential differences in amplification, we compared qPCR standards made from Bd zoospore counts for each strain, and showed that they differ significantly in amplification rates. To test potential mechanisms leading to strain differences in qPCR reaction parameters (slope and y-intercept), we: a) compared standard curves from the same strains made from extracted Bd genomic DNA in equimolar solutions, b) quantified the number of ITS1 copies per zoospore using a standard curve made from PCR-amplicons of the ITS1 region, and c) cloned and sequenced PCR-amplified ITS1 regions from these same strains to verify the presence of the probe site in all haplotypes. We found high strain variability in ITS1 copy number, ranging from 10 to 144 copies per single zoospore. Our results indicate that genome size might explain strain differences in ITS1 copy number, but not ITS1 sequence variation because the probe-binding site and primers were conserved across all haplotypes. For standards constructed from uncharacterized Bd strains, we recommend the use of single ITS1 PCR-amplicons as the absolute standard in conjunction with current quantitative assays to inform on copy number variation and provide universal estimates of pathogen zoospore loads from field-caught amphibians.
Collapse
Affiliation(s)
- Ana V Longo
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, United States of America.
| | | | | | | | | | | | | |
Collapse
|
36
|
Becker CG, Rodriguez D, Longo AV, Talaba AL, Zamudio KR. Disease risk in temperate amphibian populations is higher at closed-canopy sites. PLoS One 2012; 7:e48205. [PMID: 23118953 PMCID: PMC3485156 DOI: 10.1371/journal.pone.0048205] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2012] [Accepted: 09/20/2012] [Indexed: 01/11/2023] Open
Abstract
Habitat loss and chytridiomycosis (a disease caused by the chytrid fungus Batrachochytrium dendrobatidis - Bd) are major drivers of amphibian declines worldwide. Habitat loss regulates host-pathogen interactions by altering biotic and abiotic factors directly linked to both host and pathogen fitness. Therefore, studies investigating the links between natural vegetation and chytridiomycosis require integrative approaches to control for the multitude of possible interactions of biological and environmental variables in spatial epidemiology. In this study, we quantified Bd infection dynamics across a gradient of natural vegetation and microclimates, looking for causal associations between vegetation cover, multiple microclimatic variables, and pathogen prevalence and infection intensity. To minimize the effects of host diversity in our analyses, we sampled amphibian populations in the Adirondack Mountains of New York State, a region with relatively high single-host dominance. We sampled permanent ponds for anurans, focusing on populations of the habitat generalist frog Lithobates clamitans, and recorded various biotic and abiotic factors that potentially affect host-pathogen interactions: natural vegetation, canopy density, water temperature, and host population and community attributes. We screened for important explanatory variables of Bd infections and used path analyses to statistically test for the strength of cascading effects linking vegetation cover, microclimate, and Bd parameters. We found that canopy density, natural vegetation, and daily average water temperature were the best predictors of Bd. High canopy density resulted in lower water temperature, which in turn predicted higher Bd prevalence and infection intensity. Our results confirm that microclimatic shifts arising from changes in natural vegetation play an important role in Bd spatial epidemiology, with areas of closed canopy favoring Bd. Given increasing rates of anthropogenic habitat modification and the resulting declines in temperate and tropical frogs, understanding how vegetation cover and disease interact is critical for predicting Bd spread and developing appropriate management tools for wild populations.
Collapse
Affiliation(s)
- C Guilherme Becker
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York, USA.
| | | | | | | | | |
Collapse
|
37
|
Rodriguez D, Longo AV, Zamudio KR. Magnetic capture hybridization of Batrachochytrium dendrobatidis genomic DNA. J Microbiol Methods 2012; 90:156-9. [PMID: 22579582 DOI: 10.1016/j.mimet.2012.04.021] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 04/26/2012] [Accepted: 04/26/2012] [Indexed: 11/25/2022]
Abstract
We hybridized biotinylated probes that anneal at multiple locations throughout the Batrachochytrium dendrobatidis (Bd) genome to selectively capture Bd genomic DNA (gDNA) by binding the probe-gDNA complex to streptavidin coated magnetic beads. We then whole genome amplified the captured gDNA. This method extends the usefulness of field-collected swabs for downstream PCR-based genomic applications.
Collapse
Affiliation(s)
- David Rodriguez
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY 14853, USA.
| | | | | |
Collapse
|
38
|
López-Torres AL, Claudio-Hernández HJ, Rodríguez-Gómez CA, Longo AV, Joglar RL. Green Iguanas (Iguana iguana) in Puerto Rico: is it time for management? Biol Invasions 2011. [DOI: 10.1007/s10530-011-0057-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
39
|
Longo AV, Burrowes PA, Joglar RL. Seasonality of Batrachochytrium dendrobatidis infection in direct-developing frogs suggests a mechanism for persistence. Dis Aquat Organ 2010; 92:253-60. [PMID: 21268989 DOI: 10.3354/dao02054] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Batrachochytrium dendrobatidis (Bd), a disease-causing amphibian-specific fungus, is widely distributed in Puerto Rico, but is restricted to elevations above 600 m. The effect of this pathogen in the wild was studied by monitoring Eleutherodactylus coqui and E. portoricensis in 2 upland forests at El Yunque, a site characterized by historic population declines in the presence of chytridiomycosis. We tested a potential synergistic interaction between climate and Bd by measuring prevalence of infection and level of infection per individual sampled (number of zoospores), across the dry and wet seasons for 2 yr (between 2005 and 2007). Infection levels in adult frogs were significantly higher during the dry season in both species studied, suggesting a cyclic pattern of dry/ cool-wet/warm climate-driven synergistic interaction. These results are consistent with ex situ experiments in which E. coqui infected with Bd were more susceptible to chytridiomycosis when subjected to limited water treatments resembling drought. Long-term data on the prevalence of Bd in the populations studied versus intensity of infection in individual frogs provided contradictory information. However, the conflicting nature of these data was essential to understand the status of Bd in the species and geographical area studied. We conclude that in Puerto Rico, Bd is enzootic, and vulnerability of eleutherodactylid frogs to this pathogen is related to seasonal climatic variables. Our data suggest a mechanism by which this disease can persist in tropical frog communities without decimation of its hosts, but that complex interactions during severe droughts may lead to population crashes.
Collapse
Affiliation(s)
- Ana V Longo
- Department of Biology, University of Puerto Rico, PO Box 23360, San Juan, Puerto Rico 00931-3360.
| | | | | |
Collapse
|
40
|
Longo AV, Burrowes PA. Persistence with Chytridiomycosis does not assure survival of direct-developing frogs. Ecohealth 2010; 7:185-95. [PMID: 20585971 DOI: 10.1007/s10393-010-0327-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 05/22/2010] [Accepted: 06/01/2010] [Indexed: 05/24/2023]
Abstract
The chytrid fungus, Batrachochytrium dendrobatidis (Bd) has been linked to extinction and decline of numerous amphibians. We studied the population-level effects of Bd in two post-decline anuran species, Eleutherodactylus coqui and E. portoricensis, at El Yunque National Forest, Puerto Rico. Data on amphibian abundance was updated to report long-term population trends. Mark-recapture data was used to monitor Bd-infection status and estimate survival probabilities of infected versus uninfected adults. Prevalence of Bd (number of infected/total sampled) and individual infection level (number of zoospores) were compared among age classes at Palo Colorado Forest (661 m) and Elfin Forest (850 m). Results revealed that both species continued to decrease in Palo Colorado Forest, while in the Elfin Forest, E. portoricensis recuperated from drastic declines. Age class, season, and locality significantly predicted zoospore load. Age was also significantly associated with high zoospores loads among Bd-positive frogs, and the prevalence of Bd was higher in juveniles than adults in all populations studied. We suggest that early age represents a critical life stage in the survival of direct-developing frogs infected by this fungus. Survival probability was always higher for uninfected frogs, but recapture rates of infected versus uninfected adults were significantly different only in Palo Colorado, alerting that the negative effect of Bd infection under enzootic conditions is greater at mid-elevations. This work contributes to our understanding of how direct-developing amphibians persist with Bd, pointing to critical life stages and synergistic interactions that may induce fluctuations and/or declines in the wild.
Collapse
Affiliation(s)
- Ana V Longo
- Department of Ecology and Evolutionary Biology, Cornell University, E145 Corson Hall, Ithaca, NY 14853, USA.
| | | |
Collapse
|