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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] [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.
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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
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2
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Neely WJ, Martins RA, Mendonça da Silva CM, Ferreira da Silva T, Fleck LE, Whetstone RD, Woodhams DC, Cook WH, Prist PR, Valiati VH, Greenspan SE, Tozetti AM, Earley RL, Becker CG. Linking microbiome and stress hormone responses in wild tropical treefrogs across continuous and fragmented forests. Commun Biol 2023; 6:1261. [PMID: 38087051 PMCID: PMC10716138 DOI: 10.1038/s42003-023-05600-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 11/16/2023] [Indexed: 12/18/2023] Open
Abstract
The amphibian skin microbiome is an important component of anti-pathogen defense, but the impact of environmental change on the link between microbiome composition and host stress remains unclear. In this study, we used radiotelemetry and host translocation to track microbiome composition and function, pathogen infection, and host stress over time across natural movement paths for the forest-associated treefrog, Boana faber. We found a negative correlation between cortisol levels and putative microbiome function for frogs translocated to forest fragments, indicating strong integration of host stress response and anti-pathogen potential of the microbiome. Additionally, we observed a capacity for resilience (resistance to structural change and functional loss) in the amphibian skin microbiome, with maintenance of putative pathogen-inhibitory function despite major temporal shifts in microbiome composition. Although microbiome community composition did not return to baseline during the study period, the rate of microbiome change indicated that forest fragmentation had more pronounced effects on microbiome composition than translocation alone. Our findings reveal associations between stress hormones and host microbiome defenses, with implications for resilience of amphibians and their associated microbes facing accelerated tropical deforestation.
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Affiliation(s)
- Wesley J Neely
- Department of Biology, The University of Alabama, Tuscaloosa, AL, 35487, USA.
- Department of Biology, Texas State University, San Marcos, TX, 78666, USA.
| | - Renato A Martins
- Department of Biology, and Center for Infectious Disease Dynamics, One Health Microbiome Center, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Camila M Mendonça da Silva
- Programa de Pos‑Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022‑750, Brazil
| | - Tainá Ferreira da Silva
- Programa de Pos‑Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022‑750, Brazil
| | - Lucas E Fleck
- Programa de Pos‑Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022‑750, Brazil
| | - Ross D Whetstone
- Department of Biology, University of Massachusetts Boston, Boston, MA, 02125, USA
| | - Douglas C Woodhams
- Department of Biology, University of Massachusetts Boston, Boston, MA, 02125, USA
| | - W Harrison Cook
- Department of Biology, The University of Alabama, Tuscaloosa, AL, 35487, USA
| | - Paula R Prist
- EcoHealth Alliance, 520 Eight Avenue, Suite 1200, New York, NY, 10018, USA
| | - Victor H Valiati
- Programa de Pos‑Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022‑750, Brazil
| | - Sasha E Greenspan
- Department of Biology, The University of Alabama, Tuscaloosa, AL, 35487, USA
| | - Alexandro M Tozetti
- Programa de Pos‑Graduacão em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS, 93022‑750, Brazil
| | - Ryan L Earley
- Department of Biology, The University of Alabama, Tuscaloosa, AL, 35487, USA
| | - C Guilherme Becker
- Department of Biology, and Center for Infectious Disease Dynamics, One Health Microbiome Center, The Huck Institutes of the Life Sciences, The Pennsylvania State University, University Park, PA, 16802, USA.
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3
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Hartmann AM, McGrath-Blaser SE, Colón-Piñeiro Z, Longo AV. Ontogeny drives shifts in skin bacterial communities in facultatively paedomorphic salamanders. MICROBIOLOGY (READING, ENGLAND) 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] [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.
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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
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4
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Li A, Li Z, Leng H, Jin L, Xiao Y, Sun K, Feng J. Seasonal assembly of skin microbiota driven by neutral and selective processes in the greater horseshoe bat. Mol Ecol 2023; 32:4695-4707. [PMID: 37322601 DOI: 10.1111/mec.17051] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 05/31/2023] [Accepted: 06/07/2023] [Indexed: 06/17/2023]
Abstract
Skin microbiota play an important role in protecting bat hosts from the fungal pathogen Pseudogymnoascus destructans, which has caused dramatic bat population declines and extinctions. Recent studies have provided insights into the bacterial communities of bat skin, but variation in skin bacterial community structure in the context of the seasonal dynamics of fungal invasion, as well as the processes that drive such variation, remain largely unexplored. In this study, we characterized bat skin microbiota over the course of the bat hibernation and active season stages and used a neutral model of community ecology to determine the relative roles of neutral and selective processes in driving microbial community variation. Our results showed significant seasonal shifts in skin community structure, as well as less diverse microbiota in hibernation than in the active season. Skin microbiota were influenced by the environmental bacterial reservoir. During both the hibernation and active season stages, more than 78% of ASVs in bat skin microbiota were consistent with neutral distribution, implying that neutral processes, that is, dispersal or ecological drift contributing the most to shifts in skin microbiota. In addition, the neutral model showed that some ASVs were actively selected by the bats from the environmental bacterial reservoir, accounting for approximately 20% and 31% of the total community during hibernation and active season stages, respectively. Overall, this research provides insights into the assemblage of bat-associated bacterial communities and will aid in the development of conservation strategies against fungal disease.
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Affiliation(s)
- Aoqiang Li
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
- School of Life Sciences, Central China Normal University, Wuhan, China
| | - Zhongle Li
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
- College of Life Science, Jilin Agricultural University, Changchun, China
| | - Haixia Leng
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Longru Jin
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Yanhong Xiao
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Keping Sun
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun, China
| | - Jiang Feng
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
- College of Life Science, Jilin Agricultural University, Changchun, China
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5
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Kouete MT, Bletz MC, LaBumbard BC, Woodhams DC, Blackburn DC. Parental care contributes to vertical transmission of microbes in a skin-feeding and direct-developing caecilian. Anim Microbiome 2023; 5:28. [PMID: 37189209 PMCID: PMC10184399 DOI: 10.1186/s42523-023-00243-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 03/20/2023] [Indexed: 05/17/2023] Open
Abstract
BACKGROUND Our current understanding of vertebrate skin and gut microbiomes, and their vertical transmission, remains incomplete as major lineages and varied forms of parental care remain unexplored. The diverse and elaborate forms of parental care exhibited by amphibians constitute an ideal system to study microbe transmission, yet investigations of vertical transmission among frogs and salamanders have been inconclusive. In this study, we assess bacteria transmission in Herpele squalostoma, an oviparous direct-developing caecilian in which females obligately attend juveniles that feed on their mother's skin (dermatophagy). RESULTS We used 16S rRNA amplicon-sequencing of the skin and gut of wild caught H. squalostoma individuals (males, females, including those attending juveniles) as well as environmental samples. Sourcetracker analyses revealed that juveniles obtain an important portion of their skin and gut bacteria communities from their mother. The contribution of a mother's skin to the skin and gut of her respective juveniles was much larger than that of any other bacteria source. In contrast to males and females not attending juveniles, only the skins of juveniles and their mothers were colonized by bacteria taxa Verrucomicrobiaceae, Nocardioidaceae, and Erysipelotrichaceae. In addition to providing indirect evidence for microbiome transmission linked to parental care among amphibians, our study also points to noticeable differences between the skin and gut communities of H. squalostoma and that of many frogs and salamanders, which warrants further investigation. CONCLUSION Our study is the first to find strong support for vertical bacteria transmission attributed to parental care in a direct-developing amphibian species. This suggests that obligate parental care may promote microbiome transmission in caecilians.
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Affiliation(s)
- Marcel T Kouete
- School of Natural Resources and Environment, University of Florida, Gainesville, FL, 32611, USA.
- Department of Natural History, Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA.
| | - Molly C Bletz
- Department of Biology, University of Massachusetts, Boston, MA, 02125, USA
| | | | - Douglas C Woodhams
- Department of Biology, University of Massachusetts, Boston, MA, 02125, USA
| | - David C Blackburn
- Department of Natural History, Florida Museum of Natural History, University of Florida, Gainesville, FL, 32611, USA
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6
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Fieschi-Méric L, Van Leeuwen P, Hopkins K, Bournonville M, Denoël M, Lesbarrères D. Strong restructuration of skin microbiota during captivity challenges ex-situ conservation of amphibians. Front Microbiol 2023; 14:1111018. [PMID: 36891392 PMCID: PMC9986596 DOI: 10.3389/fmicb.2023.1111018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 01/31/2023] [Indexed: 02/22/2023] Open
Abstract
In response to the current worldwide amphibian extinction crisis, conservation instances have encouraged the establishment of ex-situ collections for endangered species. The resulting assurance populations are managed under strict biosecure protocols, often involving artificial cycles of temperature and humidity to induce active and overwintering phases, which likely affect the bacterial symbionts living on the amphibian skin. However, the skin microbiota is an important first line of defense against pathogens that can cause amphibian declines, such as the chytrid Batrachochytrium dendrobatidis (Bd). Determining whether current husbandry practices for assurance populations might deplete amphibians from their symbionts is therefore essential to conservation success. Here, we characterize the effect of the transitions from the wild to captivity, and between aquatic and overwintering phases, on the skin microbiota of two newt species. While our results confirm differential selectivity of skin microbiota between species, they underscore that captivity and phase-shifts similarly affect their community structure. More specifically, the translocation ex-situ is associated with rapid impoverishment, decrease in alpha diversity and strong species turnover of bacterial communities. Shifts between active and overwintering phases also cause changes in the diversity and composition of the microbiota, and on the prevalence of Bd-inhibitory phylotypes. Altogether, our results suggest that current husbandry practices strongly restructure the amphibian skin microbiota. Although it remains to be determined whether these changes are reversible or have deleterious effects on their hosts, we discuss methods to limit microbial diversity loss ex-situ and emphasize the importance of integrating bacterial communities to applied amphibian conservation.
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Affiliation(s)
- Léa Fieschi-Méric
- Laboratory of Ecology and Conservation of Amphibians (LECA), Freshwater and OCeanic science Unit of reSearch (FOCUS), Université de Liège, Liège, Belgium.,Biology Department, Laurentian University, Sudbury, ON, Canada
| | | | - Kevin Hopkins
- Institute of Zoology, Zoological Society of London (ZSL), London, United Kingdom
| | - Marie Bournonville
- Aquarium-Muséum de l'Université de Liège, Freshwater and OCeanic science Unit of reSearch (FOCUS), Liège, Belgium
| | - Mathieu Denoël
- Laboratory of Ecology and Conservation of Amphibians (LECA), Freshwater and OCeanic science Unit of reSearch (FOCUS), Université de Liège, Liège, Belgium
| | - David Lesbarrères
- Biology Department, Laurentian University, Sudbury, ON, Canada.,Environment and Climate Change Canada, National Wildlife Research Centre, Ottawa, ON, Canada
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7
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Bunker ME, Weiss SL. Cloacal microbiomes of sympatric and allopatric Sceloporus lizards vary with environment and host relatedness. PLoS One 2022; 17:e0279288. [PMID: 36548265 PMCID: PMC9779040 DOI: 10.1371/journal.pone.0279288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 12/02/2022] [Indexed: 12/24/2022] Open
Abstract
Animals and their microbiomes exert reciprocal influence; the host's environment, physiology, and phylogeny can impact the composition of the microbiome, while the microbes present can affect host behavior, health, and fitness. While some microbiomes are highly malleable, specialized microbiomes that provide important functions can be more robust to environmental perturbations. Recent evidence suggests Sceloporus virgatus has one such specialized microbiome, which functions to protect eggs from fungal pathogens during incubation. Here, we examine the cloacal microbiome of three different Sceloporus species (spiny lizards; Family Phrynosomatidae)-Sceloporus virgatus, Sceloporus jarrovii, and Sceloporus occidentalis. We compare two species with different reproductive modes (oviparous vs. viviparous) living in sympatry: S. virgatus and S. jarrovii. We compare sister species living in similar habitats (riparian oak-pine woodlands) but different latitudes: S. virgatus and S. occidentalis. And, we compare three populations of one species (S. occidentalis) living in different habitat types: beach, low elevation forest, and the riparian woodland. We found differences in beta diversity metrics between all three comparisons, although those differences were more extreme between animals in different environments, even though those populations were more closely related. Similarly, alpha diversity varied among the S. occidentalis populations and between S. occidentalis and S. virgatus, but not between sympatric S. virgatus and S. jarrovii. Despite these differences, all three species and all three populations of S. occcidentalis had the same dominant taxon, Enterobacteriaceae. The majority of the variation between groups was in low abundance taxa and at the ASV level; these taxa are responsive to habitat differences, geographic distance, and host relatedness. Uncovering what factors influence the composition of wild microbiomes is important to understanding the ecology and evolution of the host animals, and can lead to more detailed exploration of the function of particular microbes and the community as a whole.
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Affiliation(s)
- Marie E. Bunker
- University of Puget Sound, Tacoma, WA, United States of America
| | - Stacey L. Weiss
- University of Puget Sound, Tacoma, WA, United States of America
- * E-mail:
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8
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Goodwin KB, Hutchinson JD, Gompert Z. Spatiotemporal and ontogenetic variation, microbial selection, and predicted Bd-inhibitory function in the skin-associated microbiome of a Rocky Mountain amphibian. Front Microbiol 2022; 13:1020329. [PMID: 36583053 PMCID: PMC9792605 DOI: 10.3389/fmicb.2022.1020329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 11/22/2022] [Indexed: 12/15/2022] Open
Abstract
Host-associated microbiomes play important roles in host health and pathogen defense. In amphibians, the skin-associated microbiota can contribute to innate immunity with potential implications for disease management. Few studies have examined season-long temporal variation in the amphibian skin-associated microbiome, and the interactions between bacteria and fungi on amphibian skin remain poorly understood. We characterize season-long temporal variation in the skin-associated microbiome of the western tiger salamander (Ambystoma mavortium) for both bacteria and fungi between sites and across salamander life stages. Two hundred seven skin-associated microbiome samples were collected from salamanders at two Rocky Mountain lakes throughout the summer and fall of 2018, and 127 additional microbiome samples were collected from lake water and lake substrate. We used 16S rRNA and ITS amplicon sequencing with Bayesian Dirichlet-multinomial regression to estimate the relative abundances of bacterial and fungal taxa, test for differential abundance, examine microbial selection, and derive alpha diversity. We predicted the ability of bacterial communities to inhibit the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd), a cutaneous fungal pathogen, using stochastic character mapping and a database of Bd-inhibitory bacterial isolates. For both bacteria and fungi, we observed variation in community composition through time, between sites, and with salamander age and life stage. We further found that temporal trends in community composition were specific to each combination of salamander age, life stage, and lake. We found salamander skin to be selective for microbes, with many taxa disproportionately represented relative to the environment. Salamander skin appeared to select for predicted Bd-inhibitory bacteria, and we found a negative relationship between the relative abundances of predicted Bd-inhibitory bacteria and Bd. We hope these findings will assist in the conservation of amphibian species threatened by chytridiomycosis and other emerging diseases.
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Affiliation(s)
- Kenen B. Goodwin
- Department of Watershed Sciences, Utah State University, Logan, UT, United States,Department of Wildland Resources, Utah State University, Logan, UT, United States,*Correspondence: Kenen B. Goodwin,
| | - Jaren D. Hutchinson
- Department of Wildland Resources, Utah State University, Logan, UT, United States
| | - Zachariah Gompert
- Department of Biology, Utah State University, Logan, UT, United States
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9
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Martínez-Ugalde E, Ávila-Akerberg V, González Martínez TM, Vázquez Trejo M, Zavala Hernández D, Anaya-Morales SL, Rebollar EA. The skin microbiota of the axolotl Ambystoma altamirani is highly influenced by metamorphosis and seasonality but not by pathogen infection. Anim Microbiome 2022; 4:63. [PMID: 36503640 PMCID: PMC9743558 DOI: 10.1186/s42523-022-00215-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 10/16/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Microbiomes have been increasingly recognized as major contributors to host health and survival. In amphibians, bacterial members of the skin microbiota protect their hosts by inhibiting the growth of the fungal pathogen Batrachochytrium dendrobatidis (Bd). Even though several studies describe the influence of biotic and abiotic factors over the skin microbiota, it remains unclear how these symbiotic bacterial communities vary across time and development. This is particularly relevant for species that undergo metamorphosis as it has been shown that host physiology and ecology drastically influence diversity of the skin microbiome. RESULTS We found that the skin bacterial communities of the axolotl A. altamirani are largely influenced by the metamorphic status of the host and by seasonal variation of abiotic factors such as temperature, pH, dissolved oxygen and conductivity. Despite high Bd prevalence in these samples, the bacterial diversity of the skin microbiota did not differ between infected and non-infected axolotls, although relative abundance of particular bacteria were correlated with Bd infection intensity. CONCLUSIONS Our work shows that metamorphosis is a crucial process that shapes skin bacterial communities and that axolotls under different developmental stages respond differently to environmental seasonal variations. Moreover, this study greatly contributes to a better understanding of the factors that shape amphibian skin microbiota, especially in a largely underexplored group like axolotls (Mexican Ambystoma species).
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Affiliation(s)
- Emanuel Martínez-Ugalde
- grid.9486.30000 0001 2159 0001Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Víctor Ávila-Akerberg
- grid.412872.a0000 0001 2174 6731Instituto de Ciencias Agropecuarias y Rurales, Universidad Autónoma del Estado de México, Toluca, Mexico
| | - Tanya M. González Martínez
- grid.9486.30000 0001 2159 0001Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Montserrat Vázquez Trejo
- grid.9486.30000 0001 2159 0001Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Dalia Zavala Hernández
- grid.9486.30000 0001 2159 0001Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Sara Lucia Anaya-Morales
- grid.9486.30000 0001 2159 0001Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico ,grid.251313.70000 0001 2169 2489 Department of Biology, University of Mississippi, Oxford, MS USA
| | - Eria A. Rebollar
- grid.9486.30000 0001 2159 0001Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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10
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Xu L, Zhou J, Zheng P, Wan X, Zhu L, Huang J, Jiang J, Chen Y, Song Z. Seasonal variation significantly influenced the stochasticity of community assembly of amphibian symbiotic bacteria. Environ Microbiol 2022; 24:5734-5748. [PMID: 36156840 DOI: 10.1111/1462-2920.16224] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 09/23/2022] [Indexed: 01/12/2023]
Abstract
Seasonal variation has been shown to influence symbiotic bacterial community composition and structure in amphibians. It is still unknown how the symbiotic bacterial community assembly changes during different seasons, especially for amphibians who are particularly sensitive to environmental change. We found significant differences in the composition and diversity (alpha and beta diversity) of amphibian skin and gut bacteria. Co-occurrences network analysis showed that seasonal variation reduced the microbial network complexity of amphibians from summer to autumn. The normalized stochastic ratio (NST) and phylogenetic bin-based null model analysis (iCAMP) models showed that the same result that stochastic processes was the major factor regulating the symbiotic bacterial community assembly mechanisms of amphibians. From summer to autumn, the symbiotic bacterial community assembly mechanisms declined in the contribution of stochastic processes, while increasing in the contribution of deterministic processes. Dispersal limitation was the dominant microbial assembly mechanism, followed by homogeneous selection, and then heterogeneous selection in the symbiotic bacterial community communities of amphibians between summer and autumn. Furthermore, higher niche width of the symbiotic bacterial community of amphibians was found in summer than autumn. Overall, these results demonstrated that seasonal variation influenced amphibian symbiotic bacterial community between summer and autumn.
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Affiliation(s)
- Liangliang Xu
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China.,Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.,Observation and Research Station of Sichuan Province of Fish Resources and Environment in Upper Reaches of the Yangtze River, College of Life Sciences, Sichuan University, Chengdu, China
| | - Jin Zhou
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China.,Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Puyang Zheng
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China.,Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Xia Wan
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China.,Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Lifeng Zhu
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Jin Huang
- Shengda Hydropower Co., Ltd., Sinohydro Group Ltd., Leshan, China
| | - Jianping Jiang
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Youhua Chen
- Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China
| | - Zhaobin Song
- Key Laboratory of Bio-Resources and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, China.,Observation and Research Station of Sichuan Province of Fish Resources and Environment in Upper Reaches of the Yangtze River, College of Life Sciences, Sichuan University, Chengdu, China
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11
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Neely WJ, Greenspan SE, Stahl LM, Heraghty SD, Marshall VM, Atkinson CL, Becker CG. Habitat Disturbance Linked with Host Microbiome Dispersion and Bd Dynamics in Temperate Amphibians. MICROBIAL ECOLOGY 2022; 84:901-910. [PMID: 34671826 DOI: 10.1007/s00248-021-01897-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 10/08/2021] [Indexed: 06/13/2023]
Abstract
Anthropogenic habitat disturbances can dramatically alter ecological community interactions, including host-pathogen dynamics. Recent work has highlighted the potential for habitat disturbances to alter host-associated microbial communities, but the associations between anthropogenic disturbance, host microbiomes, and pathogens are unresolved. Amphibian skin microbial communities are particularly responsive to factors like temperature, physiochemistry, pathogen infection, and environmental microbial reservoirs. Through a field survey on wild populations of Acris crepitans (Hylidae) and Lithobates catesbeianus (Ranidae), we assessed the effects of habitat disturbance and connectivity on environmental bacterial reservoirs, Batrachochytrium dendrobatidis (Bd) infection, and skin microbiome composition. We found higher measures of microbiome dispersion (a measure of community variability) in A. crepitans from more disturbed ponds, supporting the hypothesis that disturbance increases stochasticity in biological communities. We also found that habitat disturbance limited microbiome similarity between locations for both species, suggesting greater isolation of bacterial assemblages in more disturbed areas. Higher disturbance was associated with lower Bd prevalence for A. crepitans, which could signify suboptimal microclimates for Bd in disturbed habitats. Combined, our findings show that reduced microbiome stability stemming from habitat disturbance could compromise population health, even in the absence of pathogenic infection.
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Affiliation(s)
- Wesley J Neely
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA.
| | - Sasha E Greenspan
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA
| | - Leigha M Stahl
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA
| | - Sam D Heraghty
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA
| | - Vanessa M Marshall
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA
| | - Carla L Atkinson
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA
| | - C Guilherme Becker
- Department of Biology, The University of Alabama, 1301 Sciences and Engineering Complex, 300 Hackberry Ln, Tuscaloosa, AL, 35487, USA
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12
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Le Sage EH, Ohmer MEB, LaBumbard BC, Altman KA, Reinert LK, Bednark JG, Bletz MC, Inman B, Lindauer A, McDonnell NB, Parker SK, Skerlec SM, Wantman T, Rollins‐Smith LA, Woodhams DC, Voyles J, Richards‐Zawacki CL. Localized carry‐over effects of pond drying on survival, growth, and pathogen defenses in amphibians. Ecosphere 2022. [DOI: 10.1002/ecs2.4224] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Affiliation(s)
- Emily H. Le Sage
- Department of Pathology, Microbiology and Immunology Vanderbilt University School of Medicine Nashville Tennessee USA
| | - Michel E. B. Ohmer
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | | | - Karie A. Altman
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Laura K. Reinert
- Department of Pathology, Microbiology and Immunology Vanderbilt University School of Medicine Nashville Tennessee USA
| | - Jeffery G. Bednark
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Molly C. Bletz
- Department of Biology University of Massachusetts Boston Massachusetts USA
| | - Brady Inman
- Department of Pathology, Microbiology and Immunology Vanderbilt University School of Medicine Nashville Tennessee USA
- Department of Biology University of Massachusetts Boston Massachusetts USA
| | - Alexa Lindauer
- Department of Biology University of Nevada Reno Nevada USA
| | - Nina B. McDonnell
- Department of Biology University of Massachusetts Boston Massachusetts USA
| | - Sadie K. Parker
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Samantha M. Skerlec
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Trina Wantman
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Louise A. Rollins‐Smith
- Department of Pathology, Microbiology and Immunology Vanderbilt University School of Medicine Nashville Tennessee USA
- Department of Biological Sciences Vanderbilt University Nashville Tennessee USA
- Department of Pediatrics Vanderbilt University School of Medicine Nashville Tennessee USA
| | | | - Jamie Voyles
- Department of Biology University of Nevada Reno Nevada USA
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13
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Rajarajan A, Wolinska J, Walser JC, Mäder M, Spaak P. Infection by a eukaryotic gut parasite in wild Daphnia sp. associates with a distinct bacterial community. FEMS Microbiol Ecol 2022; 98:6677393. [PMID: 36026529 PMCID: PMC9869925 DOI: 10.1093/femsec/fiac097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/04/2022] [Accepted: 08/23/2022] [Indexed: 01/26/2023] Open
Abstract
Host-associated bacterial communities play an important role in host fitness and resistance to diseases. Yet, few studies have investigated tripartite interaction between a host, parasite and host-associated bacterial communities in natural settings. Here, we use 16S rRNA gene amplicon sequencing to compare gut- and body- bacterial communities of wild water fleas belonging to the Daphnia longispina complex, between uninfected hosts and those infected with the common and virulent eukaryotic gut parasite Caullerya mesnili (Family: Ichthyosporea). We report community-level changes in host-associated bacteria with the presence of the parasite infection; namely decreased alpha diversity and increased beta diversity at the site of infection, i.e. host gut (but not host body). We also report decreased abundance of bacterial taxa proposed elsewhere to be beneficial for the host, and an appearance of taxa specifically associated with infected hosts. Our study highlights the host-microbiota-infection link in a natural system and raises questions about the role of host-associated microbiota in natural disease epidemics as well as the functional roles of bacteria specifically associated with infected hosts.
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Affiliation(s)
- Amruta Rajarajan
- Corresponding author: Office BU-G09, Überlandstrasse 133, 8600 Dübendorf, Zürich, Switzerland. E-mail: and
| | - Justyna Wolinska
- Department of Evolutionary and Integrative Ecology, Leibniz Institute of Freshwater Ecology and Inland Fisheries (IGB), 12587 Berlin, Germany,Department of Biology, Chemistry, Pharmacy, Institut für Biologie, Freie Universität Berlin (FU), 14195 Berlin, Germany
| | - Jean-Claude Walser
- Department of Environmental systems science (D-USYS), Genetic Diversity Centre (GDC), Federal Institute of Technology (ETH) Zürich, 8092, Zürich, Switzerland
| | - Minea Mäder
- Department of Aquatic Ecology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Zürich, Switzerland
| | - Piet Spaak
- Department of Aquatic Ecology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), 8600 Dübendorf, Zürich, Switzerland
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14
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Abstract
Temporal changes and transmission patterns in host-associated microbial communities have important implications for host health. The diversity of amphibian skin microbial communities is associated with disease outcome in amphibians exposed to the fungal pathogen Batrachochytrium dendrobatidis (Bd). To successfully develop conservation strategies against Bd, we need a comprehensive understanding of how skin microbes are maintained and transmitted over time within populations. We used 16S rRNA sequence analysis to compare Epipedobates anthonyi frogs housed with one conspecific to frogs housed singly at four time points over the course of 1 year. We found that both α and β diversity of frog skin bacterial communities changed significantly over the course of the experiment. Specifically, we found that bacterial communities of cohabitating frogs became more similar over time. We also observed that some bacterial taxa were differentially abundant between frogs housed singly and frogs housed with a conspecific. These results suggest that conspecific contact may play a role in mediating amphibian skin microbial diversity and that turnover of skin microbial communities can occur across time. Our findings provide rationale for future studies exploring horizontal transmission as a potential mechanism of host-associated microbial maintenance in amphibians.
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Affiliation(s)
- Ariel Kruger
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, NJ, USA
| | - Spencer Roth
- Department of Environmental Sciences, Rutgers University, New Brunswick, NJ, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN, USA
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15
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McKnight DT, Huerlimann R, Bower DS, Schwarzkopf L, Alford RA, Zenger KR. The interplay of fungal and bacterial microbiomes on rainforest frogs following a disease outbreak. Ecosphere 2022. [DOI: 10.1002/ecs2.4037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Affiliation(s)
- Donald T. McKnight
- College of Science and Engineering James Cook University Townsville Queensland Australia
| | - Roger Huerlimann
- College of Science and Engineering James Cook University Townsville Queensland Australia
- Marine Climate Change Unit Okinawa Institute of Science and Technology Onnason Okinawa Japan
| | - Deborah S. Bower
- College of Science and Engineering James Cook University Townsville Queensland Australia
- School of Environmental and Rural Science University of New England Armidale New South Wales Australia
| | - Lin Schwarzkopf
- College of Science and Engineering James Cook University Townsville Queensland Australia
| | - Ross A. Alford
- College of Science and Engineering James Cook University Townsville Queensland Australia
| | - Kyall R. Zenger
- College of Science and Engineering James Cook University Townsville Queensland Australia
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16
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Rosa GM, Perez R, Richards LA, Richards‐Zawacki CL, Smilanich AM, Reinert LK, Rollins‐Smith LA, Wetzel DP, Voyles J. Seasonality of host immunity in a tropical disease system. Ecosphere 2022. [DOI: 10.1002/ecs2.4158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Gonçalo M. Rosa
- Department of Biology University of Nevada, Reno Reno Nevada USA
- Institute of Zoology Zoological Society of London London UK
- Centre for Ecology, Evolution and Environmental Changes Faculdade de Ciências da Universidade de Lisboa Lisbon Portugal
| | - Rachel Perez
- Department of Biology New Mexico Institute of Mining and Technology Socorro New Mexico USA
| | - Lora A. Richards
- Department of Biology University of Nevada, Reno Reno Nevada USA
| | | | | | - Laura K. Reinert
- Department of Pathology Microbiology and Immunology, Vanderbilt University School of Medicine Nashville Tennessee USA
| | - Louise A. Rollins‐Smith
- Department of Pathology Microbiology and Immunology, Vanderbilt University School of Medicine Nashville Tennessee USA
| | - Daniel P. Wetzel
- Department of Biological Sciences University of Pittsburgh Pittsburgh Pennsylvania USA
| | - Jamie Voyles
- Department of Biology University of Nevada, Reno Reno Nevada USA
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17
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Shu Y, Jiang H, Yuen CNT, Wang W, He J, Zhang H, Liu G, Wei L, Chen L, Wu H. Microcystin-leucine arginine induces skin barrier damage and reduces resistance to pathogenic bacteria in Lithobates catesbeianus tadpoles. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 238:113584. [PMID: 35512477 DOI: 10.1016/j.ecoenv.2022.113584] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/22/2022] [Accepted: 04/27/2022] [Indexed: 06/14/2023]
Abstract
Despite the importance of the skin mucosal barrier and commensal microbiota for the health of amphibians, the potential of environmental contaminants to disrupt the skin mucosal barrier and microbiota have rarely been studied in toxicology. In this study, tadpoles (Lithobates catesbeianus) were exposed to 0, 0.5, and 2 μg/L of microcystin-leucine arginine (MC-LR) for 30 days to explore the impacts of environmentally realistic MC-LR concentrations on the physical skin barrier, immune barrier, commensal microbiota, and skin resistance to pathogenic bacterial invasion. MC-LR exposure significantly reduced the collagen fibrils in the dermis of skin tissues and down-regulated tight junction and stratum corneum-related gene transcriptions, suggesting the damage caused by MC-LR to the physical barrier of the skin. Increased skin eosinophils and upregulated transcriptions of inflammation-related genes in the exposed tadpoles underline the development of skin inflammation resulting from MC-LR exposure even at environmentally realistic concentrations. Comparative transcriptome and immunobiochemical analyses found that antimicrobial peptides (Brevinin-1PLc, Brevinin-2GHc, and Ranatuerin-2PLa) and lysozyme were down-regulated in the exposed groups, while complement, pattern recognition receptor, and specific immune processes were up-regulated. However, the content of endotoxin lipopolysaccharide produced by bacteria increased in a dose-dependent pattern. The disc diffusion test showed a reduced ability of skin supernatant to inhibit pathogenic bacteria in the exposed groups. Analysis of microbial 16 S rRNA gene by high-throughput sequencing revealed that MC-LR interfered with the abundance, composition, and diversity of the skin commensal microbiota, which favored the growth of pathogen-containing genera Rhodococcus, Acinetobacter, and Gordonibacter. In summary, the current study provides the first clues about the impact of MC-LR on the integrity and function of skin barrier of amphibians. These new toxicological evidences can facilitate a more comprehensive evaluation of the ecological risk of MC-LR to amphibians.
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Affiliation(s)
- Yilin Shu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China; State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Huiling Jiang
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Calista N T Yuen
- State Key Laboratory in Marine Pollution, City University of Hong Kong, Department of Chemistry, Hong Kong, China
| | - Wenchao Wang
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Jun He
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Huijuan Zhang
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Guangxuan Liu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Luting Wei
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China
| | - Lianguo Chen
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China.
| | - Hailong Wu
- Collaborative Innovation Center of Recovery and Reconstruction of Degraded Ecosystem in Wanjiang Basin Co-founded by Anhui Province and Ministry of Education, School of Ecology and Environment, Anhui Normal University, Wuhu 241002, China.
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18
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Martins RA, Greenspan SE, Medina D, Buttimer S, Marshall VM, Neely WJ, Siomko S, Lyra ML, Haddad CFB, São-Pedro V, Becker CG. Signatures of functional bacteriome structure in a tropical direct-developing amphibian species. Anim Microbiome 2022; 4:40. [PMID: 35672870 PMCID: PMC9172097 DOI: 10.1186/s42523-022-00188-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 05/17/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Host microbiomes may differ under the same environmental conditions and these differences may influence susceptibility to infection. Amphibians are ideal for comparing microbiomes in the context of disease defense because hundreds of species face infection with the skin-invading microbe Batrachochytrium dendrobatidis (Bd), and species richness of host communities, including their skin bacteria (bacteriome), may be exceptionally high. We conducted a landscape-scale Bd survey of six co-occurring amphibian species in Brazil’s Atlantic Forest. To test the bacteriome as a driver of differential Bd prevalence, we compared bacteriome composition and co-occurrence network structure among the six focal host species.
Results
Intensive sampling yielded divergent Bd prevalence in two ecologically similar terrestrial-breeding species, a group with historically low Bd resistance. Specifically, we detected the highest Bd prevalence in Ischnocnema henselii but no Bd detections in Haddadus binotatus. Haddadus binotatus carried the highest bacteriome alpha and common core diversity, and a modular network partitioned by negative co-occurrences, characteristics associated with community stability and competitive interactions that could inhibit Bd colonization.
Conclusions
Our findings suggest that community structure of the bacteriome might drive Bd resistance in H. binotatus, which could guide microbiome manipulation as a conservation strategy to protect diverse radiations of direct-developing species from Bd-induced population collapses.
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19
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Kim SA, Kang N, Park T. Hierarchical Structured Component Analysis for Microbiome Data Using Taxonomy Assignments. IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 2022; 19:1302-1312. [PMID: 33211665 DOI: 10.1109/tcbb.2020.3039326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The recent advent of high-throughput sequencing technology has enabled us to study the associations between human microbiome and diseases. The DNA sequences of microbiome samples are clustered as operational taxonomic units (OTUs) according to their similarity. The OTU table containing counts of OTUs present in each sample is used to measure correlations between OTUs and disease status and find key microbes for prediction of the disease status. Various statistical methods have been proposed for such microbiome data analysis. However, none of these methods reflects the hierarchy of taxonomy information. In this paper, we propose a hierarchical structural component model for microbiome data (HisCoM-microb) using taxonomy information as well as OTU table data. The proposed HisCoM-microb consists of two layers: one for OTUs and the other for taxa at the higher taxonomy level. Then we calculate simultaneously coefficient estimates of OTUs and taxa of the two layers inserted in the hierarchical model. Through this analysis, we can infer the association between taxa or OTUs and disease status, considering the impact of taxonomic structure on disease status. Both simulation study and real microbiome data analysis show that HisCoM-microb can successfully reveal the relations between each taxon and disease status and identify the key OTUs of the disease at the same time.
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20
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Li Z, Li A, Dai W, Leng H, Liu S, Jin L, Sun K, Feng J. Skin Microbiota Variation Among Bat Species in China and Their Potential Defense Against Pathogens. Front Microbiol 2022; 13:808788. [PMID: 35432245 PMCID: PMC9009094 DOI: 10.3389/fmicb.2022.808788] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 02/18/2022] [Indexed: 11/13/2022] Open
Abstract
Host-associated skin bacteria are essential for resisting pathogen infections and maintaining health. However, we have little understanding of how chiropteran skin microbiota are distributed among bat species and their habitats, or of their putative roles in defending against Pseudogymnoascus destructans in China. In this study, we characterized the skin microbiomes of four bat species at five localities using 16S rRNA gene amplicon sequencing to understand their skin microbial composition, structure, and putative relationship with disease. The alpha- and beta-diversities of skin microbiota differed significantly among the bat species, and the differences were affected by environmental temperature, sampling sites, and host body condition. The chiropteran skin microbial communities were enriched in bacterial taxa that had low relative abundances in the environment. Most of the potential functions of skin microbiota in bat species were associated with metabolism. Focusing on their functions of defense against pathogens, we found that skin microbiota could metabolize a variety of active substances that could be potentially used to fight P. destructans. The skin microbial communities of bats in China are related to the environment and the bat host, and may be involved in the host's defense against pathogens.
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Affiliation(s)
- Zhongle Li
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Aoqiang Li
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun, China
| | - Wentao Dai
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Haixia Leng
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Sen Liu
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Longru Jin
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Keping Sun
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
- Key Laboratory of Vegetation Ecology, Ministry of Education, Changchun, China
| | - Jiang Feng
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
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21
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Chen MY, Kueneman JG, González A, Humphrey G, Knight R, McKenzie VJ. Predicting fungal infection rate and severity with skin-associated microbial communities on amphibians. Mol Ecol 2022; 31:2140-2156. [PMID: 35076975 DOI: 10.1111/mec.16372] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 12/16/2021] [Accepted: 01/18/2022] [Indexed: 11/28/2022]
Abstract
Pathogen success (risk and severity) is influenced by host-associated microbiota, but the degree to which variation in microbial community traits predict future infection presence/absence (risk) and load (severity) for the host is unknown. We conducted a time-series experiment by sampling the skin-associated bacterial communities of five amphibian species before and after exposure to the fungal pathogen, Batrachochytrium dendrobaditis (Bd). We ask whether microbial community traits are predictors of, or are affected by, Bd infection risk and intensity. Our results show that richness of putative Bd-inhibitory bacteria strongly predicts infection risk, while the proportion of putative Bd-inhibitory bacteria predicts future infection intensity. Variation in microbial community composition is high across time and individual, and bacterial prevalence is low. Our findings demonstrate how ecological community traits of host-associated microbiota may be used to predict infection risk by pathogenic microbes.
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Affiliation(s)
- Melissa Y Chen
- Department of Ecology and Evolutionary Biology, University of Colorado, Ramaley N-122, UCB 334, Boulder, CO, 80309, USA
| | - Jordan G Kueneman
- Smithsonian Tropical Research Institute, Luis Clement Avenue, Bldg. 401 Tupper, Balboa Ancon, Panama, Republic of Panama
| | - Antonio González
- Department of Pediatrics, Bioengineering and Computer Science and Engineering, and Center for Microbiome Innovation, University of California, Gilman Drive, La Jolla, San Diego, CA, 92093, USA
| | - Greg Humphrey
- Department of Pediatrics, Bioengineering and Computer Science and Engineering, and Center for Microbiome Innovation, University of California, Gilman Drive, La Jolla, San Diego, CA, 92093, USA
| | - Rob Knight
- Department of Pediatrics, Bioengineering and Computer Science and Engineering, and Center for Microbiome Innovation, University of California, Gilman Drive, La Jolla, San Diego, CA, 92093, USA
| | - Valerie J McKenzie
- Department of Ecology and Evolutionary Biology, University of Colorado, Ramaley N-122, UCB 334, Boulder, CO, 80309, USA
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22
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Bacterial biofilm thickness and fungal-inhibitory bacterial richness both prevent establishment of the amphibian fungal pathogen, Batrachochytrium dendrobatidis. Appl Environ Microbiol 2022; 88:e0160421. [PMID: 35044804 DOI: 10.1128/aem.01604-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Host-associated microbial biofilms can provide protection against pathogen establishment. In many host-microbe symbioses (including, but not limited to: humans, plants, insects, and amphibians), there is a correlation between host-associated microbial diversity and pathogen infection risk. Diversity may prevent infection by pathogens through sampling effects and niche complementarity- but an alternative hypothesis may be that microbial biomass is confounded with diversity, and that host-associated biofilms are deterring pathogen establishment through space pre-emption. In this study, we use the amphibian system as a model for host-microbe-pathogen interactions to ask two questions: (1) is bacterial richness confounded with biofilm thickness or cell density, and (2) to what extent does biofilm thickness, cell density, and bacterial richness each deter the establishment of the amphibian fungal pathogen, Batrachochytrium dendrobatidis (Bd)? To answer these questions, we built a custom biofilm microcosm that mimics the host-environment interface by allowing nutrients to diffuse out of a fine-pore biofilm scaffolding. This created a competitive environment in which bacteria and the fungal pathogen compete for colonization space. We then challenged bacterial biofilms ranging in community richness, biofilm thickness, bacterial cell density, and Bd-inhibitory metabolite production with live Bd zoospores to determine how Bd establishment success on membranes vary. We found that biofilm thickness and Bd-inhibitory isolate richness work in complement to reduce Bd establishment success. This work underscores that physical aspects of biofilm communities can play a large role in pathogen inhibition and in many studies, these traits are not studied. IMPORTANCE Our finding highlights the fact that diversity, as measured through 16S rDNA sequencing, may obscure the true mechanisms behind microbe-mediated pathogen defence, and that physical space occupation by biofilm-forming symbionts may significantly contribute to pathogen protection. These findings have implications across a wide range of host-microbe systems, since 16S rDNA sequencing is a standard tool used across many microbial systems. Further, our results are potentially relevant to many host-pathogen systems, since host-associated bacterial biofilms are ubiquitous.
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23
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Nava-González B, Suazo-Ortuño I, López PB, Maldonado-López Y, Lopez-Toledo L, Raggi L, Parra-Olea G, Alvarado-Díaz J, Gómez-Gil B. Inhibition of Batrachochytrium dendrobatidis Infection by Skin Bacterial Communities in Wild Amphibian Populations. MICROBIAL ECOLOGY 2021; 82:666-676. [PMID: 33598748 DOI: 10.1007/s00248-021-01706-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
Skin-associated bacteria are known to inhibit infection by the fungal pathogen Batrachochytrium dendrobatidis (Bd) in amphibians. It has also been postulated that skin-associated bacterial community is related to Bd infection intensity. However, our understanding of host microbial dynamics and their importance in regulating Bd intensity is limited. We analyzed Bd infection and skin-associated bacteria from two amphibian species, the salamander Ambystoma rivulare and the frog Lithobates spectabilis that co-occurred in a tropical high-altitude site in central Mexico. Sixty-three percent of sampled salamander individuals and 80% of frog individuals tested positive for Bd. Overall, we registered 622 skin-associated bacterial genera, from which 73 are known to have Bd inhibitory effects. These inhibitory taxa represented a relative abundance of 50% in relation to total relative bacterial abundance. Our results indicated that, although sharing some bacterial taxa, bacterial community from the skin of both species was different in taxonomic composition and in relative abundance. Pseudomonas spp. and Stenotrophomonas spp. were among the five most abundant bacterial taxa of both species. Both bacterial taxa inhibit Bd infection. We detected that bacterial richness and relative abundance of inhibitory Bd bacteria were negatively related to intensity of Bd infection independent of species and seasons. Despite the high Bd prevalence in both host species, no dead or sick individuals were registered during field surveys. The relatively low levels of Bd load apparently do not compromise survival of host species. Therefore, our results suggested that individuals analyzed were able to survive and thrive under a dynamic relation with enzootic infections of Bd and their microbiota.
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Affiliation(s)
- Bisbrian Nava-González
- Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Juanito Itzícuaro SN, Nueva Esperanza, 58330, Morelia, Michoacán, México
| | - Ireri Suazo-Ortuño
- Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Juanito Itzícuaro SN, Nueva Esperanza, 58330, Morelia, Michoacán, México.
| | - Perla Bibian López
- Universidad Tecnológica de Morelia, Avenida Vicepresidente Pino Suárez 750, Cd. Industrial, 58200, Morelia, Michoacán, México
| | - Yurixhi Maldonado-López
- CONACyT-Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Juanito Itzícuaro SN, Nueva Esperanza, 58330, Morelia, Michoacán, México
| | - Leonel Lopez-Toledo
- Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Juanito Itzícuaro SN, Nueva Esperanza, 58330, Morelia, Michoacán, México
| | - Luciana Raggi
- CONACYT-Instituto de Investigaciones Agropecuarias y Forestales, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Juanito Itzícuaro SN, Nueva Esperanza, 58330, Morelia, Michoacán, México
| | - Gabriela Parra-Olea
- Instituto de Biología, Universidad Nacional Autónoma de México, Cd de México, México
| | - Javier Alvarado-Díaz
- Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Avenida Juanito Itzícuaro SN, Nueva Esperanza, 58330, Morelia, Michoacán, México
| | - Bruno Gómez-Gil
- CIAD A.C., Mazatlán Unit for Aquaculture, AP 711, Mazatlán, 82000, Sinaloa, México
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24
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Ellison S, Knapp R, Vredenburg V. Longitudinal patterns in the skin microbiome of wild, individually marked frogs from the Sierra Nevada, California. ISME COMMUNICATIONS 2021; 1:45. [PMID: 37938625 PMCID: PMC9723788 DOI: 10.1038/s43705-021-00047-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 08/04/2021] [Accepted: 08/17/2021] [Indexed: 05/29/2023]
Abstract
The amphibian skin microbiome has been the focus of numerous studies because of the protective effects that some bacteria provide against the pathogenic fungus Batrachochytrium dendrobatidis, which has caused a global panzootic among amphibians. However, the mechanisms driving community structure and function in the amphibian skin microbiome are still poorly understood, and longitudinal analyses of the skin microbiome have not yet been conducted in wild populations. In this study, we investigate longitudinal patterns in the skin microbiome of 19 individually marked adult frogs from two wild populations of the endangered Sierra Nevada yellow-legged frog (Rana sierrae), sampled over the course of 2 years. We found that individuals with low bacterial diversity (dominated by order Burkhorderiales) had significantly more stable bacterial communities than those with higher diversity. Amplicon sequence variants (ASVs) with high relative abundance were significantly less transient than those with low relative abundance, and ASVs with intermediate-level relative abundances experienced the greatest volatility over time. Based on these results, we suggest that efforts to develop probiotic treatments to combat B. dendrobatidis should focus on bacteria that are found at high relative abundances in some members of a population, as these strains are more likely to persist and remain stable in the long term.
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Affiliation(s)
- Silas Ellison
- Department of Biology, San Francisco State University, San Francisco, California, USA.
| | - Roland Knapp
- Sierra Nevada Aquatic Research Laboratory, University of California, Mammoth Lakes, CA, USA
| | - Vance Vredenburg
- Department of Biology, San Francisco State University, San Francisco, California, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, California, USA
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25
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Walke JB, Becker MH, Krinos A, Chang EAB, Santiago C, Umile TP, Minbiole KPC, Belden LK. Seasonal changes and the unexpected impact of environmental disturbance on skin bacteria of individual amphibians in a natural habitat. FEMS Microbiol Ecol 2021; 97:6024676. [PMID: 33278302 DOI: 10.1093/femsec/fiaa248] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 12/02/2020] [Indexed: 01/16/2023] Open
Abstract
Amphibians host diverse skin bacteria that have a role in pathogen defense, but these skin communities could change over time and impact this function. Here, we monitored individual Eastern red-spotted newts (Notophthalmus viridescens; N = 17) for 2 years in a field pond enclosure and assessed the effects of season and disturbance on skin bacterial community dynamics. We created disturbances by adding additional pond substrate to the enclosure at two timepoints. We planned to sample the skin bacterial community and metabolite profiles of each newt every 6 weeks; we ultimately sampled eight individuals at least six times. We used 16S rRNA gene amplicon sequencing to characterize the bacterial communities and HPLC-MS for metabolite profiling. We found that disturbance had a dramatic effect on skin bacterial communities and metabolite profiles, while season had an effect only using select metrics. There were seven core bacterial taxa (97% OTUs) that were found on all newts in all seasons, pre- and post-disturbance. Lastly, there was a correlation between bacterial and metabolite profiles post-disturbance, which was not observed pre-disturbance. This longitudinal study suggests that environmental disturbances can have lasting effects on skin bacterial communities that overwhelm seasonal changes, although the core bacteria remain relatively consistent over time.
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Affiliation(s)
- Jenifer B Walke
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Matthew H Becker
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | - Arianna Krinos
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
| | | | - Celina Santiago
- Department of Chemistry, Villanova University, Villanova, PA 19085, USA
| | - Thomas P Umile
- Department of Chemistry, Villanova University, Villanova, PA 19085, USA
| | | | - Lisa K Belden
- Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA
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26
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Bijnens K, Thijs S, Leynen N, Stevens V, McAmmond B, Van Hamme J, Vangronsveld J, Artois T, Smeets K. Differential effect of silver nanoparticles on the microbiome of adult and developing planaria. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2021; 230:105672. [PMID: 33227667 DOI: 10.1016/j.aquatox.2020.105672] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/04/2020] [Accepted: 10/27/2020] [Indexed: 05/23/2023]
Abstract
Silver nanoparticles (AgNPs) are widely incorporated in household, consumer and medical products. Their unintentional release via wastewaters raises concerns on their environmental impact, particularly for aquatic organisms and their associated bacterial communities. It is known that the microbiome plays an important role in its host's health and physiology, e.g. by producing essential nutrients and providing protection against pathogens. A thorough understanding of the effects of AgNPs on bacterial communities and on their interactions with the host is crucial to fully assess AgNP toxicity on aquatic organisms. Our results indicate that the microbiome of the invertebrate Schmidtea mediterranea, a freshwater planarian, is affected by AgNP exposure at the tested 10 μg/ml concentration. Using targeted amplification of the bacterial 16S rRNA gene V3-V4 region, two independent experiments on the microbiomes of adult worms revealed a consistent decrease in Betaproteobacteriales after AgNP exposure, mainly attributed to a decrease in Curvibacter and Undibacterium. Although developing tissues and organisms are known to be more sensitive to toxic compounds, three independent experiments in regenerating worms showed a less pronounced effect of AgNP exposure on the microbiome, possibly because underlying bacterial community changes during development mask the AgNP induced effect. The presence of a polyvinyl-pyrrolidone (PVP) coating did not significantly alter the outcome of the experiments compared to those with uncoated particles. The observed variation between the different experiments underlines the highly variable nature of microbiomes and emphasises the need to repeat microbiome experiments, within and between physiological states of the animal.
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Affiliation(s)
- Karolien Bijnens
- Centre for Environmental Sciences, Zoology, Biodiversity and Toxicology, Hasselt University, Hasselt, Belgium
| | - Sofie Thijs
- Centre for Environmental Sciences, Environmental Biology, Hasselt University, Hasselt, Belgium
| | - Nathalie Leynen
- Centre for Environmental Sciences, Zoology, Biodiversity and Toxicology, Hasselt University, Hasselt, Belgium
| | - Vincent Stevens
- Centre for Environmental Sciences, Environmental Biology, Hasselt University, Hasselt, Belgium
| | - Breanne McAmmond
- Department of Biological Sciences, Thompson Rivers University, Kamloops, British Columbia, Canada
| | - Jonathan Van Hamme
- Department of Biological Sciences, Thompson Rivers University, Kamloops, British Columbia, Canada
| | - Jaco Vangronsveld
- Centre for Environmental Sciences, Environmental Biology, Hasselt University, Hasselt, Belgium; Department of Plant Physiology, Faculty of Biology and Biotechnology, Maria Skłodowska-Curie University, Lublin, Poland
| | - Tom Artois
- Centre for Environmental Sciences, Zoology, Biodiversity and Toxicology, Hasselt University, Hasselt, Belgium
| | - Karen Smeets
- Centre for Environmental Sciences, Zoology, Biodiversity and Toxicology, Hasselt University, Hasselt, Belgium.
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27
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Douglas AJ, Hug LA, Katzenback BA. Composition of the North American Wood Frog (Rana sylvatica) Bacterial Skin Microbiome and Seasonal Variation in Community Structure. MICROBIAL ECOLOGY 2021; 81:78-92. [PMID: 32613267 DOI: 10.1007/s00248-020-01550-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 06/22/2020] [Indexed: 06/11/2023]
Abstract
While a number of amphibian skin microbiomes have been characterized, it is unclear how these communities might vary in response to seasonal changes in the environment and the corresponding behaviors that many amphibians exhibit. Given recent studies demonstrating the importance of the skin microbiome in frog innate immune defense against pathogens, investigating how changes in the environment impact the microbial species present will provide a better understanding of conditions that may alter host susceptibility to pathogens in their environment. We sampled the bacterial skin microbiome of North American wood frogs (Rana sylvatica) from two breeding ponds in the spring, along with the bacterial community present in their vernal breeding pools, and frogs from the nearby forest floor in the summer and fall to determine whether community composition differs by sex, vernal pond site, or temporally across season (spring, summer, fall). Taxon relative abundance data reveals a profile of bacterial phyla similar to those previously described on anuran skin, with Proteobacteria, Bacteroidetes, and Actinobacteria dominating the wood frog skin microbiome. Our results indicate that sex had no significant effect on skin microbiota diversity; however, this may be due to our limited female frog sample size. Vernal pool site had a small but significant effect on skin microbiota, but skin-associated communities were more similar to each other than to the communities observed in the frogs' respective pond water. Across seasons, diversity analyses suggest that there are significant differences between the bacterial skin microbiome of frogs from spring and summer/fall groups while the average α-diversity per frog remained consistent. These results illustrate seasonal variation in wood frog skin microbiome structure and highlight the importance of considering temporal trends in an amphibian microbiome, particularly for species whose life history requires recurrent shifts in habitat and behavior.
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Affiliation(s)
- Alexander J Douglas
- Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
| | - Laura A Hug
- Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
| | - Barbara A Katzenback
- Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.
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28
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Ruthsatz K, Lyra ML, Lambertini C, Belasen AM, Jenkinson TS, da Silva Leite D, Becker CG, Haddad CFB, James TY, Zamudio KR, Toledo LF, Vences M. Skin microbiome correlates with bioclimate and Batrachochytrium dendrobatidis infection intensity in Brazil's Atlantic Forest treefrogs. Sci Rep 2020; 10:22311. [PMID: 33339839 PMCID: PMC7749163 DOI: 10.1038/s41598-020-79130-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 12/04/2020] [Indexed: 12/20/2022] Open
Abstract
In Brazil’s Atlantic Forest (AF) biodiversity conservation is of key importance since the fungal pathogen Batrachochytrium dendrobatidis (Bd) has led to the rapid loss of amphibian populations here and worldwide. The impact of Bd on amphibians is determined by the host's immune system, of which the skin microbiome is a critical component. The richness and diversity of such cutaneous bacterial communities are known to be shaped by abiotic factors which thus may indirectly modulate host susceptibility to Bd. This study aimed to contribute to understanding the environment-host–pathogen interaction determining skin bacterial communities in 819 treefrogs (Anura: Hylidae and Phyllomedusidae) from 71 species sampled across the AF. We investigated whether abiotic factors influence the bacterial community richness and structure on the amphibian skin. We further tested for an association between skin bacterial community structure and Bd co-occurrence. Our data revealed that temperature, precipitation, and elevation consistently correlate with richness and diversity of the skin microbiome and also predict Bd infection status. Surprisingly, our data suggest a weak but significant positive correlation of Bd infection intensity and bacterial richness. We highlight the prospect of future experimental studies on the impact of changing environmental conditions associated with global change on environment-host–pathogen interactions in the AF.
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Affiliation(s)
- Katharina Ruthsatz
- Institute of Zoology, Universität Hamburg, Martin-Luther-King-Platz 3, 20146, Hamburg, Germany. .,Zoological Institute, Technische Universität Braunschweig, Mendelssohnstraße 4, 38106, Brunswick, Germany.
| | - Mariana L Lyra
- Laboratório de Herpetologia, Depto de Biodiversidade, Instituto de Biociências and Centro de Aquicultura (CAUNESP), Universidade Estadual Paulista - UNESP, Rio Claro, 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, 13083-862, Brazil
| | - Anat M Belasen
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853-2701, USA
| | - Thomas S Jenkinson
- Department of Wildlife, Fish and Conservation Biology, University of California, Davis, Davis, CA, USA
| | - Domingos da Silva Leite
- Laboratório de Antígenos Bacterianos II, Departamento de Genética, Evolução, Microbiologia e Imunologia, Instituto de Biologia, Universidade Estadual de Campinas, Caixa Postal 6109, Campinas, São Paulo, CEP 13083-862, Brazil
| | - C Guilherme Becker
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL, 35847, USA
| | - Célio F B Haddad
- Laboratório de Herpetologia, Depto de Biodiversidade, Instituto de Biociências and Centro de Aquicultura (CAUNESP), Universidade Estadual Paulista - UNESP, Rio Claro, São Paulo, Brazil
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Kelly R Zamudio
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, 14853-2701, USA
| | - 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, 13083-862, Brazil
| | - Miguel Vences
- Zoological Institute, Technische Universität Braunschweig, Mendelssohnstraße 4, 38106, Brunswick, Germany
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29
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Le Sage EH, LaBumbard BC, Reinert LK, Miller BT, Richards-Zawacki CL, Woodhams DC, Rollins-Smith LA. Preparatory immunity: Seasonality of mucosal skin defences and Batrachochytrium infections in Southern leopard frogs. J Anim Ecol 2020; 90:542-554. [PMID: 33179786 DOI: 10.1111/1365-2656.13386] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 10/28/2020] [Indexed: 12/14/2022]
Abstract
Accurately predicting the impacts of climate change on wildlife health requires a deeper understanding of seasonal rhythms in host-pathogen interactions. The amphibian pathogen, Batrachochytrium dendrobatidis (Bd), exhibits seasonality in incidence; however, the role that biological rhythms in host defences play in defining this pattern remains largely unknown. The aim of this study was to examine whether host immune and microbiome defences against Bd correspond with infection risk and seasonal fluctuations in temperature and humidity. Over the course of a year, five populations of Southern leopard frogs (Rana [Lithobates] sphenocephala) in Tennessee, United States, were surveyed for host immunity, microbiome and pathogen dynamics. Frogs were swabbed for pathogen load and skin bacterial diversity and stimulated to release stored antimicrobial peptides (AMPs). Secretions were analysed to estimate total hydrophobic peptide concentrations, presence of known AMPs and effectiveness of Bd growth inhibition in vitro. The diversity and proportion of bacterial reads with a 99% match to sequences of isolates known to inhibit Bd growth in vitro were used as an estimate of predicted anti-Bd function of the skin microbiome. Batrachochytrium dendrobatidis dynamics followed the expected seasonal fluctuations-peaks in cooler months-which coincided with when host mucosal defences were most potent against Bd. Specifically, the concentration and expression of stored AMPs cycled synchronously with Bd dynamics. Although microbiome changes followed more linear trends over time, the proportion of bacteria that can function to inhibit Bd growth was greatest when risk of Bd infection was highest. We interpret the increase in peptide storage in the fall and the shift to a more anti-Bd microbiome over winter as a preparatory response for subsequent infection risk during the colder periods when AMP synthesis and bacterial growth is slow and pathogen pressure from this cool-adapted fungus is high. Given that a decrease in stored AMP concentrations as temperatures warm in spring likely means greater secretion rates, the subsequent decrease in prevalence suggests seasonality of Bd in this host may be in part regulated by annual immune rhythms, and dominated by the effects of temperature.
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Affiliation(s)
- Emily H Le Sage
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | | | - Laura K Reinert
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Brian T Miller
- Department of Biology, Middle Tennessee State University, Murfreesboro, TN, USA
| | | | - Doug C Woodhams
- Department of Biology, University of Massachusetts, Boston, MA, USA
| | - Louise A Rollins-Smith
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University School of Medicine, Nashville, TN, USA.,Department of Biological Sciences, Vanderbilt University, Nashville, TN, USA.,Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN, USA
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30
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Stencel A. Do seasonal microbiome changes affect infection susceptibility, contributing to seasonal disease outbreaks? Bioessays 2020; 43:e2000148. [PMID: 33165975 DOI: 10.1002/bies.202000148] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/24/2020] [Accepted: 09/29/2020] [Indexed: 12/13/2022]
Abstract
The aim of the present paper is to explore whether seasonal outbreaks of infectious diseases may be linked to changes in host microbiomes. This is a very important issue, because one way to have more control over seasonal outbreaks is to understand the factors that underlie them. In this paper, I will evaluate the relevance of the microbiome as one of such factors. The paper is based on two pillars of reasoning. Firstly, on the idea that microbiomes play an important role in their hosts' defence against infectious diseases. Secondly, on the idea that microbiomes are not stable, but change seasonally. These two ideas are combined in order to argue that seasonal changes in a given microbiome may influence the functionality of the host's immune system and consequently make it easier for infectious agents to infect the host at certain times of year. I will argue that, while this is only a theoretical possibility, certain studies may back up such claims. Furthermore, I will show that this does not necessarily contradict other hypotheses aimed at explaining seasonal outbreaks; in fact, it may even enhance them.
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Affiliation(s)
- Adrian Stencel
- Institute of Philosophy, Jagiellonian University, Kraków, Poland
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31
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Tong Q, Cui LY, Hu ZF, Du XP, Abid HM, Wang HB. Environmental and host factors shaping the gut microbiota diversity of brown frog Rana dybowskii. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 741:140142. [PMID: 32615421 DOI: 10.1016/j.scitotenv.2020.140142] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/24/2020] [Revised: 05/18/2020] [Accepted: 06/10/2020] [Indexed: 06/11/2023]
Abstract
Symbiotic microbial communities are common in amphibians, and the composition of gut microbial communities varies with factors such as host phylogeny, life stage, ecology, and diet. However, little is known regarding how amphibians acquire their microbiota or how their growth, development, and environmental factors affect the diversity of their microbiotas. We sampled the gut microbiota during different developmental stages of brown frog Rana dybowskii, including tadpoles (T), frogs in metamorphosis (M), frogs just post-metamorphosis and after eating (F), juvenile frogs in summer (Js), adult frogs in summer (As), adult frogs in autumn (Aa), and hibernating frogs (Ah). We recorded data on the environmental (ambient temperature, fasting status, habitat, and season) and host (body mass and developmental period) factors. We investigated whether the gut microbiota diversity of R. dybowskii differs according to the host developmental stage via high-throughput Illumina sequencing and whether the gut microbiota diversity is affected by environmental and host factors. We found that alpha and beta diversity varied significantly during different developmental stages. The linear discriminant analysis effect size (LEfSe) analysis identified eight phyla exhibiting significant differences: Cyanobacteria (T group), Proteobacteria (M group), Fusobacteria (F group), Firmicutes (As group), Actinobacteria (Aa group), Verrucomicrobia (Aa group), Tenericutes (Aa group), and Bacteroidetes (Ah group). The Venn diagrams showed that 49 shared OTUs were present during all stages of development, whereas 10 OTUs were present in >90% of the samples. The environmental and host factors were significantly correlated with microbial community changes. Furthermore, the AIC-based model results suggested that development was the only variable that needed inclusion in the redundancy analysis (RDA) to explain the variance in taxa. These results have broad implications for our understanding of gut microbiota development and its associations with amphibian development and environmental factors.
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Affiliation(s)
- Qing Tong
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, China; Hejiang Forestry Research Institute of Heilongjiang Province, Jiamusi, China
| | - Li-Yong Cui
- Hejiang Forestry Research Institute of Heilongjiang Province, Jiamusi, China
| | - Zong-Fu Hu
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Xiao-Peng Du
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Hayat Muhammad Abid
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, China
| | - Hong-Bin Wang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, China.
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32
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Brannelly LA, McCallum HI, Grogan LF, Briggs CJ, Ribas MP, Hollanders M, Sasso T, Familiar López M, Newell DA, Kilpatrick AM. Mechanisms underlying host persistence following amphibian disease emergence determine appropriate management strategies. Ecol Lett 2020; 24:130-148. [PMID: 33067922 DOI: 10.1111/ele.13621] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Revised: 06/18/2020] [Accepted: 09/08/2020] [Indexed: 12/19/2022]
Abstract
Emerging infectious diseases have caused many species declines, changes in communities and even extinctions. There are also many species that persist following devastating declines due to disease. The broad mechanisms that enable host persistence following declines include evolution of resistance or tolerance, changes in immunity and behaviour, compensatory recruitment, pathogen attenuation, environmental refugia, density-dependent transmission and changes in community composition. Here we examine the case of chytridiomycosis, the most important wildlife disease of the past century. We review the full breadth of mechanisms allowing host persistence, and synthesise research on host, pathogen, environmental and community factors driving persistence following chytridiomycosis-related declines and overview the current evidence and the information required to support each mechanism. We found that for most species the mechanisms facilitating persistence have not been identified. We illustrate how the mechanisms that drive long-term host population dynamics determine the most effective conservation management strategies. Therefore, understanding mechanisms of host persistence is important because many species continue to be threatened by disease, some of which will require intervention. The conceptual framework we describe is broadly applicable to other novel disease systems.
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Affiliation(s)
- Laura A Brannelly
- Veterinary BioSciences, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Werribee, Vic, 3030, Australia
| | - Hamish I McCallum
- Environmental Futures Research Institute and School of Environment and Science, Griffith University, Nathan, Qld., 4111, Australia
| | - Laura F Grogan
- Environmental Futures Research Institute and School of Environment and Science, Griffith University, Nathan, Qld., 4111, Australia.,Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Cheryl J Briggs
- Ecology, Evolution and Marine Biology, University of California Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Maria P Ribas
- Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia.,Wildlife Conservation Medicine Research Group, Departament de Medicina i Cirurgia Animals, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain
| | - Matthijs Hollanders
- Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Thais Sasso
- Environmental Futures Research Institute and School of Environment and Science, Griffith University, Nathan, Qld., 4111, Australia
| | - Mariel Familiar López
- School of Environment and Sciences, Griffith University, Gold Coast, Qld., 4215, Australia
| | - David A Newell
- Forest Research Centre, School of Environment, Science and Engineering, Southern Cross University, Lismore, NSW, 2480, Australia
| | - Auston M Kilpatrick
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, 95064, USA
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33
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Preuss JF, Greenspan SE, Rossi EM, Lucas Gonsales EM, Neely WJ, Valiati VH, Woodhams DC, Becker CG, Tozetti AM. Widespread Pig Farming Practice Linked to Shifts in Skin Microbiomes and Disease in Pond-Breeding Amphibians. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:11301-11312. [PMID: 32845628 DOI: 10.1021/acs.est.0c03219] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Farming practices may reshape the structure of watersheds, water quality, and the health of aquatic organisms. Nutrient enrichment from agricultural pollution increases disease pressure in many host-pathogen systems, but the mechanisms underlying this pattern are not always resolved. For example, nutrient enrichment should strongly influence pools of aquatic environmental bacteria, which has the potential to alter microbiome composition of aquatic animals and their vulnerability to disease. However, shifts in the host microbiome have received little attention as a link between nutrient enrichment and diseases of aquatic organisms. We examined nutrient enrichment through the widespread practice of integrated pig-fish farming and its effects on microbiome composition of Brazilian amphibians and prevalence of the globally distributed amphibian skin pathogen Batrachochytrium dendrobatidis (Bd). This farming system drove surges in fecal coliform bacteria, disturbing amphibian skin bacterial communities such that hosts recruited higher proportions of Bd-facilitative bacteria and carried higher Bd prevalence. Our results highlight previously overlooked connections between global trends in land use change, microbiome dysbiosis, and wildlife disease. These interactions may be particularly important for disease management in the tropics, a region with both high biodiversity and continually intensifying anthropogenic pressures on aquatic wildlife habitats.
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Affiliation(s)
- Jackson F Preuss
- Programa de Pós-Graduação em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS 93022-750, Brazil
- Departamento de Ciências da Vida, Universidade do Oeste de Santa Catarina, São Miguel do Oeste, SC 89900-000, Brazil
| | - Sasha E Greenspan
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Eliandra M Rossi
- Departamento de Ciências da Vida, Universidade do Oeste de Santa Catarina, São Miguel do Oeste, SC 89900-000, Brazil
| | - Elaine M Lucas Gonsales
- Departamento de Zootecnia e Ciências Biológicas, Universidade Federal de Santa Maria, RS 98300-000, Brazil
| | - Wesley J Neely
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Victor Hugo Valiati
- Programa de Pós-Graduação em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS 93022-750, Brazil
| | - Douglas C Woodhams
- Department of Biology, University of Massachusetts Boston, Boston, Massachusetts 02125, United States
| | - C Guilherme Becker
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487, United States
| | - Alexandro M Tozetti
- Programa de Pós-Graduação em Biologia, Universidade do Vale do Rio dos Sinos, São Leopoldo, RS 93022-750, Brazil
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Abstract
Understanding the interactions between host behavior and microbiome dynamics remains an outstanding priority in the field of microbial ecology. Here, we provide the reader with a simple example of how the behavior and living environment of wild amphibians shape their symbiotic microbiome externally (on the skin) and internally (in the stomach and gut). Seasonal dynamics in symbiotic microbiomes have been investigated in a number of vertebrates and are mainly caused by changes in the diet (in the gut microbiome) or the living environment (in the skin microbiome). Most amphibian microbiome studies focus on the skin, whereas internal microbiome structure and dynamics are often overlooked. The present study investigated the seasonal dynamics in three types of symbiotic microbiomes (the skin, stomach, and gut) across four wild frog species, belonging to different families, in May and October. The frogs harbored more water source microbes in May than in October. On the contrary, the frogs harbored more soil source microbes in October than in May. The frog species investigated tend to live in a water environment in May to maintain body surface humidity at high environmental temperatures and to breed. In October, these four species prefer to live on the land, as the environmental temperature decreases, to prepare for hibernation in caves or under stones. Thus, seasonal changes in the wild amphibian symbiotic microbiome may be caused by the difference in microbe transmission from their living environment due to specific behaviors. This study demonstrated that the behavior and living environment of wild amphibians shape their symbiotic microbiome externally (on the skin) and internally (in the stomach and gut). We revealed the potential association between specific behaviors in poikilothermic animals and host symbiotic microbiomes. IMPORTANCE Understanding the interactions between host behavior and microbiome dynamics remains an outstanding priority in the field of microbial ecology. Here, we provide the reader with a simple example of how the behavior and living environment of wild amphibians shape their symbiotic microbiome externally (on the skin) and internally (in the stomach and gut).
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Kruger A. Frog Skin Microbiota Vary With Host Species and Environment but Not Chytrid Infection. Front Microbiol 2020; 11:1330. [PMID: 32670233 PMCID: PMC7328345 DOI: 10.3389/fmicb.2020.01330] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Accepted: 05/25/2020] [Indexed: 01/15/2023] Open
Abstract
Describing the structure and function of the amphibian cutaneous microbiome has gained importance with the spread of Batrachochytrium dendrobatidis (Bd), the fungal pathogen that can cause the skin disease chytridiomycosis. Sampling amphibian skin microbiota is needed to characterize current infection status and to help predict future susceptibility to Bd based on microbial composition since some skin microbes have antifungal capabilities that may confer disease resistance. Here, I use 16S rRNA sequencing to describe the composition and structure of the cutaneous microbiota of six species of amphibians. Frog skin samples were also tested for Bd, and I found 11.8% Bd prevalence among all individuals sampled (n = 76). Frog skin microbiota varied by host species and sampling site, but did not differ among Bd-positive and Bd-negative individuals. These results suggest that bacterial composition reflects host species and the environment, but does not reflect Bd infection among the species sampled here. Of the bacterial OTUs identified using an indicator species analysis as strongly associated with amphibians, significantly more indicator OTUs were putative anti-Bd taxa than would be expected based on the proportion of anti-Bd OTUs among all frog OTUs, suggesting strong associations between host species and anti-Bd OTUs. This relationship may partially explain why some of these frogs are asymptomatic carriers of Bd, but more work is needed to determine the other factors that contribute to interspecific variation in Bd susceptibility. This work provides important insights on inter- and intra-specific variation in microbial community composition, putative function, and disease dynamics in populations of amphibians that appear to be coexisting with Bd.
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Affiliation(s)
- Ariel Kruger
- Department of Ecology, Evolution, and Natural Resources, Rutgers University, New Brunswick, NJ, United States
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36
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Assessing similarities and disparities in the skin microbiota between wild and laboratory populations of house mice. ISME JOURNAL 2020; 14:2367-2380. [PMID: 32518248 PMCID: PMC7490391 DOI: 10.1038/s41396-020-0690-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 05/15/2020] [Accepted: 05/22/2020] [Indexed: 12/23/2022]
Abstract
The house mouse is a key model organism in skin research including host–microbiota interactions, yet little is known about the skin microbiota of free-living mice. It is similarly unclear how closely laboratory mice, which typically live under exceptionally hygienic conditions, resemble the ancestral state of microbial variation in the wild. In this study, we sampled an area spanning 270 km2 in south-west France and collected 203 wild Mus musculus domesticus. We profiled the ear skin microbiota on standing and active communities (DNA-based and RNA-based 16 rRNA gene sequencing, respectively), and compared multiple community aspects between wild-caught and laboratory-reared mice kept in distinct facilities. Compared to lab mice, we reveal the skin microbiota of wild mice on the one hand to be unique in their composition within the Staphylococcus genus, with a majority of sequences most closely matching known novobiocin-resistant species, and display evidence of a rare biosphere. On the other hand, despite drastic disparities between natural and laboratory environments, we find that shared taxa nonetheless make up the majority of the core skin microbiota of both wild- and laboratory skin communities, suggesting that mammalian skin is a highly specialized habitat capable of strong selection from available species pools. Finally, the influence of environmental factors suggests RNA-based profiling as a preferred method to reduce environmental noise.
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37
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Yin Z, Sun K, Li A, Sun D, Li Z, Xiao G, Feng J. Changes in the gut microbiota during Asian particolored bat ( Vespertilio sinensis) development. PeerJ 2020; 8:e9003. [PMID: 32435532 PMCID: PMC7227643 DOI: 10.7717/peerj.9003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Accepted: 03/26/2020] [Indexed: 12/26/2022] Open
Abstract
Background The gut microbiota is closely linked to host development, diet and health and is influenced by both the host and the environment. Although many studies have focused on the dynamics of the gut microbiota during development in captive animals, few studies have focused on the dynamics of the gut microbiota during development in wild animals, especially for the order Chiroptera. Methods In this study, we characterized the gut microbiota of the wild Asian particolored bat (Vespertilio sinensis) from 1 day to 6 weeks after birth. We explored the changes in their gut microbial community compositions, examined possible influencing factors, and predicted the feeding transition period. Results The gut microbiota changed during the development of V. sinensis. The alpha diversity of the bats' gut microbiota gradually increased but did not change significantly from the 1st day to the 4th week after birth; however, the alpha diversity decreased significantly in week 5, then stabilized. The beta diversity differed slightly in weeks 4-6. In week 4, the fecal samples showed the highest diversity in bacterial community composition. Thus, we predicted that the potential feeding transition period for V. sinensis may occur during week 4. Redundancy analysis showed that age and body mass index significantly affected the compositional changes of the gut microbiota in Asian particolored bats. Conclusion The gut microbiota changed during the development of V. sinensis. We suggest that changes in the alpha and beta diversity during week 4 after birth indicate a potential feeding transition, highlighting the importance of diet in the gut microbiota during the development of V. sinensis.
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Affiliation(s)
- Zhongwei Yin
- College of Life Science, Jilin Agricultural University, Changchun, China.,Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Keping Sun
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Aoqiang Li
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Deyi Sun
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Zhongle Li
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China.,College of Animal Science and Technology, Jilin Agricultural University, Changchun, China
| | - Guohong Xiao
- Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
| | - Jiang Feng
- College of Life Science, Jilin Agricultural University, Changchun, China.,Jilin Provincial Key Laboratory of Animal Resource Conservation and Utilization, Northeast Normal University, Changchun, China
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38
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Bernardo-Cravo AP, Schmeller DS, Chatzinotas A, Vredenburg VT, Loyau A. Environmental Factors and Host Microbiomes Shape Host-Pathogen Dynamics. Trends Parasitol 2020; 36:616-633. [PMID: 32402837 DOI: 10.1016/j.pt.2020.04.010] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2019] [Revised: 04/11/2020] [Accepted: 04/11/2020] [Indexed: 12/18/2022]
Abstract
Microorganisms are increasingly recognized as ecosystem-relevant components because they affect the population dynamics of hosts. Functioning at the interface of the host and pathogen, skin and gut microbiomes are vital components of immunity. Recent work reveals a strong influence of biotic and abiotic environmental factors (including the environmental microbiome) on disease dynamics, yet the importance of the host-host microbiome-pathogen-environment interaction has been poorly reflected in theory. We use amphibians and the disease chytridiomycosis caused by the fungal pathogen Batrachochytrium dendrobatidis to show how interactions between host, host microbiome, pathogen, and the environment all affect disease outcome. Our review provides new perspectives that improve our understanding of disease dynamics and ecology by incorporating environmental factors and microbiomes into disease theory.
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Affiliation(s)
- Adriana P Bernardo-Cravo
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France; Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstrasse 15, 04318, Leipzig, Germany
| | - Dirk S Schmeller
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France.
| | - Antonis Chatzinotas
- Helmholtz Centre for Environmental Research - UFZ, Department of Environmental Microbiology, Permoserstrasse 15, 04318, Leipzig, Germany; Leipzig University, Institute of Biology, Johannisallee 21-23, 04103 Leipzig, Germany; German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Deutscher Platz 5e, Leipzig, 04103, Germany
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
| | - Adeline Loyau
- ECOLAB, Université de Toulouse, CNRS, INPT, UPS, Toulouse, France; Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Alte Fischerhütte 2, Stechlin, D-16775, Germany
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39
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Tong Q, Hu ZF, Du XP, Bie J, Wang HB. Effects of Seasonal Hibernation on the Similarities Between the Skin Microbiota and Gut Microbiota of an Amphibian (Rana dybowskii). MICROBIAL ECOLOGY 2020; 79:898-909. [PMID: 31820074 DOI: 10.1007/s00248-019-01466-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2018] [Accepted: 11/14/2019] [Indexed: 06/10/2023]
Abstract
Both the gut and skin microbiotas have important functions for amphibians. The gut microbiota plays an important role in both the health and evolution of the host species, whereas the role of skin microbiota in disease resistance is particularly important for amphibians. Many studies have examined the effects of environmental factors on the skin and gut microbiotas, but no study has yet explored the similarities between the skin and gut microbiotas. In this study, the gut and skin microbiotas of Rana dybowskii in summer and winter were investigated via high-throughput Illumina sequencing. The results showed that the alpha diversity of gut and skin microbiotas decreased significantly from summer to winter. In both seasons, the microbial composition and structure differed significantly between the gut and skin, and the similarities between these microbiotas differed between seasons. The pairwise distances between the gut and skin microbiotas were greater in winter than in summer. The ratio of core OTUs and shared OTUs to the sum of the OTUs in the gut and skin microbiotas in summer was significantly higher than that in winter. The similarities between the gut and skin microbiotas are important for understanding amphibian ecology and life history.
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Affiliation(s)
- Qing Tong
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
- Key Laboratory of the Provincial Education Department of Heilongjiang for Common Animal Disease Prevention and Treatment, Harbin, 150030, China
| | - Zong-Fu Hu
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Xiao-Peng Du
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Jia Bie
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China
| | - Hong-Bin Wang
- College of Veterinary Medicine, Northeast Agricultural University, Harbin, 150030, People's Republic of China.
- Key Laboratory of the Provincial Education Department of Heilongjiang for Common Animal Disease Prevention and Treatment, Harbin, 150030, China.
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40
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Uren Webster TM, Rodriguez-Barreto D, Castaldo G, Gough P, Consuegra S, Garcia de Leaniz C. Environmental plasticity and colonisation history in the Atlantic salmon microbiome: A translocation experiment. Mol Ecol 2020; 29:886-898. [PMID: 32011775 PMCID: PMC7078932 DOI: 10.1111/mec.15369] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 01/11/2020] [Accepted: 01/29/2020] [Indexed: 12/20/2022]
Abstract
Microbial communities associated with the gut and the skin are strongly influenced by environmental factors, and can rapidly adapt to change. Historical processes may also affect the microbiome. In particular, variation in microbial colonisation in early life has the potential to induce lasting effects on microbial assemblages. However, little is known about the relative extent of microbiome plasticity or the importance of historical colonisation effects following environmental change, especially for nonmammalian species. To investigate this we performed a reciprocal translocation of Atlantic salmon between artificial and semi-natural conditions. Wild and hatchery-reared fry were transferred to three common garden experimental environments for 6 weeks: standard hatchery conditions, hatchery conditions with an enriched diet, and simulated wild conditions. We characterized the faecal and skin microbiome of individual fish before and after the environmental translocation, using a BACI (before-after-control-impact) design. We found evidence of extensive microbiome plasticity for both the gut and skin, with the greatest changes in alpha and beta diversity associated with the largest changes in environment and diet. Microbiome richness and diversity were entirely determined by environment, with no detectable effects of fish origin, and there was also a near-complete turnover in microbiome structure. However, we also identified, for the first time in fish, evidence of historical colonisation effects reflecting early-life experience, including ASVs characteristic of captive rearing. These results have important implications for host adaptation to local selective pressures, and highlight how conditions experienced during early life can have a long-term influence on the microbiome and, potentially, host health.
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Affiliation(s)
- Tamsyn M Uren Webster
- Centre for Sustainable Aquatic Research, College of Science, Swansea University, Swansea, UK
| | | | - Giovanni Castaldo
- Centre for Sustainable Aquatic Research, College of Science, Swansea University, Swansea, UK
| | - Peter Gough
- Cynrig Fish Culture Unit, Natural Resources Wales, Llanfrynach, UK
| | - Sofia Consuegra
- Centre for Sustainable Aquatic Research, College of Science, Swansea University, Swansea, UK
| | - Carlos Garcia de Leaniz
- Centre for Sustainable Aquatic Research, College of Science, Swansea University, Swansea, UK
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41
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Xu LL, Chen H, Zhang M, Zhu W, Chang Q, Lu G, Chen Y, Jiang J, Zhu L. Changes in the community structure of the symbiotic microbes of wild amphibians from the eastern edge of the Tibetan Plateau. Microbiologyopen 2020; 9:e1004. [PMID: 32045512 PMCID: PMC7142363 DOI: 10.1002/mbo3.1004] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2019] [Revised: 10/31/2019] [Accepted: 01/15/2020] [Indexed: 12/11/2022] Open
Abstract
Environment has a potential effect on the animal symbiotic microbiome. Here, to study the potential relationship of the symbiotic microbiomes of wild amphibians with altitude, we collected the gut and skin samples from frogs (nine species) and the environmental samples (water and soil samples) from the Leshan Mountains (altitude: 360–410 m) and Gongga Mountains (altitude: 3340–3989 m) on the eastern edge of the Tibetan Plateau. Bufo gargarizans (Bg) samples were collected from both the Leshan and Gongga mountain regions (Bg was the only species sampled on both mountains). The DNA extracted from each sample was performed high‐throughput sequencing (MiSeq) of bacterial 16S rRNA gene amplicons. High relative abundance of Caulobacteraceae and Sphingomonadaceae was found in skin samples from both Bg and the other high‐altitude amphibians (nine species combined). High relative abundance of Coxiellaceae and Mycoplasmataceae was found in gut samples from both Bg and the other high‐altitude amphibians. Furthermore, the alpha and beta diversities of skin and gut samples from Bg and the other amphibian species (nine species combined) were similar. In terms of the symbiotic microbial community, the low‐altitude samples were less diverse and more similar to each other than the high‐altitude samples were. We speculated that extreme high‐altitude environments and host phylogeny may affect the amphibian microbiome. Despite the distinct microbial community differences between the skin and gut microbiomes, some functions were similar in the Bg and combined high‐altitude samples. The Bg and high‐altitude skin samples had higher oxidative stress tolerance and biofilm formation than the low‐altitude skin samples. However, the opposite results were observed for the Bg and high‐altitude gut samples. Further study is required to determine whether these characteristics favor high‐altitude amphibian adaptation to extreme environments.
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Affiliation(s)
- Liang Liang Xu
- Chengdu Institute of BiologyChinese Academy of SciencesChengduChina
- College of Life SciencesNanjing Normal UniversityNanjingChina
| | - Hua Chen
- Shanghai Biozeron Bioinformatics CenterShanghaiChina
| | - Mengjie Zhang
- Chengdu Institute of BiologyChinese Academy of SciencesChengduChina
- College of Life SciencesNanjing Normal UniversityNanjingChina
| | - Wei Zhu
- Chengdu Institute of BiologyChinese Academy of SciencesChengduChina
| | - Qing Chang
- College of Life SciencesNanjing Normal UniversityNanjingChina
| | - Guoqing Lu
- Department of BiologyUniversity of Nebraska at OmahaOmahaNEUSA
| | - Youhua Chen
- Chengdu Institute of BiologyChinese Academy of SciencesChengduChina
| | - Jianping Jiang
- Chengdu Institute of BiologyChinese Academy of SciencesChengduChina
| | - Lifeng Zhu
- College of Life SciencesNanjing Normal UniversityNanjingChina
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42
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Barnes EM, Carter EL, Lewis JD. Predicting Microbiome Function Across Space Is Confounded by Strain-Level Differences and Functional Redundancy Across Taxa. Front Microbiol 2020; 11:101. [PMID: 32117131 PMCID: PMC7018939 DOI: 10.3389/fmicb.2020.00101] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 01/17/2020] [Indexed: 12/30/2022] Open
Abstract
Variation in the microbiome among individual organisms may play a critical role in the relative susceptibility of those organisms to infection, disease, and death. However, predicting microbiome function is difficult because of spatial and temporal variation in microbial diversity, and taxonomic diversity is not predictive of microbiome functional diversity. Addressing this issue may be particularly important when addressing pandemic diseases, such as the global amphibian die-off associated with Bd. Some of the most important factors in probiotic development for disease treatment are whether bacteria with desired function can be found on native amphibians in the local environment. To address this issue, we isolated, sequenced, and assayed the cutaneous bacterial communities of Plethodon cinereus along a gradient of land use change. Our results suggest that cutaneous community composition, but not overall diversity, change with changes in land use, but this does not correspond to significant change in Bd-inhibitory function. We found that Bd-inhibition is a functionally redundant trait, but that level of inhibition varies over phylogenetic, spatial, and temporal scales. This research provides further evidence for the importance of continued examination of amphibian microbial communities across environmental gradients, including biotic and abiotic interactions, when considering disease dynamics.
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Affiliation(s)
- Elle M Barnes
- Department of Biological Sciences, Louis Calder Center - Biological Field Station, Fordham University, Armonk, NY, United States.,Department of Biological Sciences and Center for Urban Ecology, Fordham University, Bronx, NY, United States
| | - Erin L Carter
- Department of Biological Sciences and Center for Urban Ecology, Fordham University, Bronx, NY, United States
| | - J D Lewis
- Department of Biological Sciences, Louis Calder Center - Biological Field Station, Fordham University, Armonk, NY, United States.,Department of Biological Sciences and Center for Urban Ecology, Fordham University, Bronx, NY, United States
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43
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Kruger A. Functional Redundancy of Batrachochytrium dendrobatidis Inhibition in Bacterial Communities Isolated from Lithobates clamitans Skin. MICROBIAL ECOLOGY 2020; 79:231-240. [PMID: 31165187 DOI: 10.1007/s00248-019-01387-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 04/29/2019] [Indexed: 06/09/2023]
Abstract
The cutaneous microbial community can influence the health of amphibians exposed to Batrachochytrium dendrobatidis (Bd), a fungal pathogen that has contributed to recent amphibian declines. Resistance to Bd in amphibian populations is correlated with the presence of anti-Bd cutaneous microbes, which confer disease resistance by inhibiting Bd growth. I aimed to determine if green frogs (Lithobates clamitans), an abundant and widely distributed species in New Jersey, harbored bacteria that inhibit Bd and whether the presence and identity of these microbes varied among sites. I used in vitro challenge assays to determine if bacteria isolated from green frog skin could inhibit or enhance the growth of Bd. I found that green frogs at all sites harbored anti-Bd bacteria. However, there were differences in Bd inhibition capabilities among bacterial isolates identified as the same operational taxonomic unit (OTU), lending support to the idea that phylogenetic relatedness does not always predict Bd inhibition status. Additionally, anti-Bd bacterial richness did not vary by site, but the composition of anti-Bd bacterial taxa was distinct at each site. This suggests that there is functional redundancy of Bd inhibition across unique communities of anti-Bd symbionts found on frogs at different sites. These findings highlight the need to better elucidate the structure-function relationship of microbiomes and their role in disease resistance.
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Affiliation(s)
- Ariel Kruger
- Graduate Program in Ecology and Evolution, Department of Ecology, Evolution, and Natural Resources, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, NJ, 08901, USA.
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Campbell LJ, Pawlik AH, Harrison XA. Amphibian ranaviruses in Europe: important directions for future research. Facets (Ott) 2020. [DOI: 10.1139/facets-2020-0007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Ranaviruses are an emerging group of pathogens capable of infecting all cold-blooded vertebrates. In Europe, ranaviruses pose a particularly potent threat to wild amphibian populations. Since the 1980s research on amphibian-infecting ranaviruses in Europe has been growing. The wide distribution of amphibian populations in Europe, the ease with which many are monitored, and the tractable nature of counterpart ex situ experimental systems have provided researchers with a unique opportunity to study many aspects of host–ranavirus interactions in the wild. These characteristics of European amphibian populations will also enable researchers to lead the way as the field of host–ranavirus interactions progresses. In this review, we provide a summary of the current key knowledge regarding amphibian infecting ranaviruses throughout Europe. We then outline important areas of further research and suggest practical ways each could be pursued. We address the study of potential interactions between the amphibian microbiome and ranaviruses, how pollution may exacerbate ranaviral disease either as direct stressors of amphibians or indirect modification of the amphibian microbiome. Finally, we discuss the need for continued surveillance of ranaviral emergence in the face of climate change.
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Affiliation(s)
- Lewis J. Campbell
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53711, USA
| | - Alice H. Pawlik
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall TR10 9FE, UK
| | - Xavier A. Harrison
- Centre for Ecology and Conservation, University of Exeter, Penryn, Cornwall TR10 9FE, UK
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45
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Harrison XA, Price SJ, Hopkins K, Leung WTM, Sergeant C, Garner TWJ. Diversity-Stability Dynamics of the Amphibian Skin Microbiome and Susceptibility to a Lethal Viral Pathogen. Front Microbiol 2019; 10:2883. [PMID: 31956320 PMCID: PMC6951417 DOI: 10.3389/fmicb.2019.02883] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 11/29/2019] [Indexed: 12/20/2022] Open
Abstract
Variation among animals in their host-associated microbial communities is increasingly recognized as a key determinant of important life history traits including growth, metabolism, and resistance to disease. Quantitative estimates of the factors shaping the stability of host microbiomes over time at the individual level in non-model organisms are scarce. Addressing this gap in our knowledge is important, as variation among individuals in microbiome stability may represent temporal gain or loss of key microbial species and functions linked to host health and/or fitness. Here we use controlled experiments to investigate how both heterogeneity in microbial species richness of the environment and exposure to the emerging pathogen Ranavirus influence the structure and temporal dynamics of the skin microbiome in a vertebrate host, the European common frog (Rana temporaria). Our evidence suggests that altering the bacterial species richness of the environment drives divergent temporal microbiome dynamics of the amphibian skin. Exposure to ranavirus effects changes in skin microbiome structure irrespective of total microbial diversity, but individuals with higher pre-exposure skin microbiome diversity appeared to exhibit higher survival. Higher diversity skin microbiomes also appear less stable over time compared to lower diversity microbiomes, but stability of the 100 most abundant ("core") community members was similar irrespective of microbiome richness. Our study highlights the importance of extrinsic factors in determining the stability of host microbiomes over time, which may in turn have important consequences for the stability of host-microbe interactions and microbiome-fitness correlations.
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Affiliation(s)
- Xavier A Harrison
- Institute of Zoology, Zoological Society of London, London, United Kingdom.,Centre for Ecology and Conservation, University of Exeter, Exeter, United Kingdom
| | - Stephen J Price
- Institute of Zoology, Zoological Society of London, London, United Kingdom.,UCL Genetics Institute, University College London, London, United Kingdom
| | - Kevin Hopkins
- Institute of Zoology, Zoological Society of London, London, United Kingdom
| | - William T M Leung
- Institute of Zoology, Zoological Society of London, London, United Kingdom
| | - Chris Sergeant
- Institute of Zoology, Zoological Society of London, London, United Kingdom
| | - Trenton W J Garner
- Institute of Zoology, Zoological Society of London, London, United Kingdom
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46
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Garcia-Recinos L, Burrowes PA, Dominguez-Bello M. The Skin Microbiota of Eleutherodactylus Frogs: Effects of Host Ecology, Phylogeny, and Local Environment. Front Microbiol 2019; 10:2571. [PMID: 31781069 PMCID: PMC6856660 DOI: 10.3389/fmicb.2019.02571] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Accepted: 10/23/2019] [Indexed: 01/08/2023] Open
Abstract
Amphibian skin microbiota has a potential protective role against diseases. However, the effects of environmental and host factors on symbiotic bacterial communities are not well understood. Caribbean frogs in the genus Eleutherodactylus represent a case of congeneric species that differ in ecological specialization by the process of adaptive radiation. For a small clade of Eleutherodactylus from Puerto Rico, we investigated the role of local environments, host species, and microhabitat in the composition of their skin microbiome. The potential congruence between microbial communities in hosts that are most closely related phylogenetically was also addressed. We hypothesized that the skin microbiota of Eleutherodactylus frogs would be mostly associated to microhabitat use, but also differ according to locality, and to a lesser extent to host species. To test this hypothesis, we swabbed the skin of a total of 98 adult individuals of seven Eleutherodactylus species distributed in two nearby localities in Puerto Rico, and sequenced the V4 region of the 16S rRNA gene. Results showed that locality had the greatest effect on determining skin bacterial communities of amphibian hosts, but this effect was stronger on the composition (based on presence/absence) than on its structure (based on sequence abundance). The most ecologically distinct host, E. cooki, and the generalist E. coqui presented, respectively, the most dissimilar and similar microbiota compared to other hosts. Host phylogeny showed a weak influence on skin microbiota. Results suggest that both local environment and ecological specialization are structuring the skin bacterial community in these Eleutherodactylus species, but that characteristics intrinsic to species may also render unique hosts the ability to maintain distinct microbiotas.
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Affiliation(s)
- Liza Garcia-Recinos
- Department of Biology, University of Puerto Rico, San Juan, Puerto Rico
- Centro de Estudios Conservacionistas, Universidad de San Carlos de Guatemala, Guatemala, Guatemala
| | | | - Maria Dominguez-Bello
- Department of Biology, University of Puerto Rico, San Juan, Puerto Rico
- Department of Biochemistry and Microbiology, Rutgers University, New Brunswick, NJ, United States
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Hughey MC, Sokol ER, Walke JB, Becker MH, Belden LK. Ecological Correlates of Large-Scale Turnover in the Dominant Members of Pseudacris crucifer Skin Bacterial Communities. MICROBIAL ECOLOGY 2019; 78:832-842. [PMID: 30949751 DOI: 10.1007/s00248-019-01372-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 03/22/2019] [Indexed: 06/09/2023]
Abstract
Animals host a wide diversity of symbiotic microorganisms that contribute important functions to host health, and our knowledge of what drives variation in the composition of these complex communities continues to grow. Microbiome studies at larger spatial scales present opportunities to evaluate the contribution of large-scale factors to variation in the microbiome. We conducted a large-scale field study to assess variation in the bacterial symbiont communities on adult frog skin (Pseudacris crucifer), characterized using 16S rRNA gene amplicon sequencing. We found that skin bacterial communities on frogs were less diverse than, and structurally distinct from, the surrounding habitat. Frog skin was typically dominated by one of two bacterial OTUs: at western sites, a Proteobacteria dominated the community, whereas eastern sites were dominated by an Actinobacteria. Using a metacommunity framework, we then sought to identify factors explaining small- and large-scale variation in community structure-that is, among hosts within a pond, and among ponds spanning the study transect. We focused on the presence of a fungal skin pathogen, Batrachochytrium dendrobatidis (Bd) as one potential driver of variation. We found no direct link between skin bacterial community structure and Bd infection status of individual frog hosts. Differences in pond-level community structure, however, were explained by Bd infection prevalence. Importantly, Bd infection prevalence itself was correlated with numerous other environmental factors; thus, skin bacterial diversity may be influenced by a complex suite of extrinsic factors. Our findings indicate that large-scale factors and processes merit consideration when seeking to understand microbiome diversity.
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Affiliation(s)
- Myra C Hughey
- Biology Department, Vassar College, Poughkeepsie, NY, USA.
- Department of Biological Sciences, Virginia Tech, 4088 Derring Hall, 926 West Campus Drive, Blacksburg, VA, USA.
| | - Eric R Sokol
- Department of Biological Sciences, Virginia Tech, 4088 Derring Hall, 926 West Campus Drive, Blacksburg, VA, USA
- Battelle, National Ecological Observatory Network (NEON), Boulder, CO, USA
- Institute of Arctic and Alpine Research (INSTAAR), University of Colorado Boulder, Boulder, CO, USA
| | - Jenifer B Walke
- Department of Biological Sciences, Virginia Tech, 4088 Derring Hall, 926 West Campus Drive, Blacksburg, VA, USA
- Department of Biology, Eastern Washington University, Cheney, WA, USA
| | - Matthew H Becker
- Department of Biological Sciences, Virginia Tech, 4088 Derring Hall, 926 West Campus Drive, Blacksburg, VA, USA
- Department of Biology and Chemistry, Liberty University, Lynchburg, VA, USA
| | - Lisa K Belden
- Department of Biological Sciences, Virginia Tech, 4088 Derring Hall, 926 West Campus Drive, Blacksburg, VA, USA
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Jiménez RR, Alvarado G, Estrella J, Sommer S. Moving Beyond the Host: Unraveling the Skin Microbiome of Endangered Costa Rican Amphibians. Front Microbiol 2019; 10:2060. [PMID: 31572313 PMCID: PMC6751270 DOI: 10.3389/fmicb.2019.02060] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Accepted: 08/21/2019] [Indexed: 01/12/2023] Open
Abstract
Some neotropical amphibians, including a few species in Costa Rica, were presumed to be "extinct" after dramatic population declines in the late 1980s but have been rediscovered in isolated populations. Such populations seem to have evolved a resistance/tolerance to Batrachochytrium dendrobatidis (Bd), a fungal pathogen that causes a deadly skin disease and is considered one of the main drivers of worldwide amphibian declines. The skin microbiome is an important component of the host's innate immune system and is associated with Bd-resistance. However, the way that the bacterial diversity of the skin microbiome confers protection against Bd in surviving species remains unclear. We studied variation in the skin microbiome and the prevalence of putatively anti-Bd bacterial taxa in four co-habiting species in the highlands of the Juan Castro Blanco National Park in Costa Rica using 16S rRNA amplicon sequencing. Lithobates vibicarius, Craugastor escoces, and Isthmohyla rivularis have recently been rediscovered, whereas Isthmohyla pseudopuma has suffered population fluctuations but has never disappeared. To investigate the life stage at which the protective skin microbiome is shaped and when shifts occur in the diversity of putatively anti-Bd bacteria, we studied the skin microbiome of tadpoles, juveniles and adults of L. vibicarius. We show that the skin bacterial composition of sympatric species and hosts with distinct Bd-infection statuses differs at the phyla, family, and genus level. We detected 94 amplicon sequence variants (ASVs) with putative anti-Bd activity pertaining to distinct bacterial taxa, e.g., Pseudomonas spp., Acinetobacter johnsonii, and Stenotrophomonas maltophilia. Bd-uninfected L. vibicarius harbored 79% more putatively anti-Bd ASVs than Bd-infected individuals. Although microbiome composition and structure differed across life stages, the diversity of putative anti-Bd bacteria was similar between pre- and post-metamorphic stages of L. vibicarius. Despite low sample size, our results support the idea that the skin microbiome is dynamic and protects against ongoing Bd presence in endangered species persisting after their presumed extinction. Our study serves as a baseline to understand the microbial patterns in species of high conservation value. Identification of microbial signatures linked to variation in disease susceptibility might, therefore, inform mitigation strategies for combating the global decline of amphibians.
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Affiliation(s)
- Randall R. Jiménez
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
| | - Gilbert Alvarado
- Laboratory of Comparative Wildlife Pathology, School of Veterinary Medicine and Animal Sciences, University of São Paulo, São Paulo, Brazil
- Laboratory of Experimental and Comparative Pathology (LAPECOM), Biology School, University of Costa Rica, San José, Costa Rica
| | - Josimar Estrella
- Laboratory of Experimental and Comparative Pathology (LAPECOM), Biology School, University of Costa Rica, San José, Costa Rica
| | - Simone Sommer
- Institute of Evolutionary Ecology and Conservation Genomics, University of Ulm, Ulm, Germany
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Sandmeier F, Leonard K, Tracy C, Drake K, Esque T, Nussear K, Germano J. Tools to understand seasonality in health: quantification of microbe loads and analyses of compositional ecoimmunological data reveal complex patterns in Mojave Desert Tortoise (Gopherus agassizii) populations. CAN J ZOOL 2019. [DOI: 10.1139/cjz-2018-0255] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Using data from six wild Mojave Desert Tortoise (Gopherus agassizii (Cooper, 1861)) populations, we quantified seasonal differences in immune system measurements and microbial load in the respiratory tract, pertinent to this species’ susceptibility to upper respiratory tract disease. We quantified bacteria-killing activity of blood plasma and differential leukocyte counts to detect trends in temporal variation in immune function. We used centered log-ratio (clr) transformations of leukocyte counts and stress that such transformations are necessary for compositional data. We tested animals for the potential pathogen Pasteurella testudinis Snipes and Biberstein, 1982 with a newly created quantitative polymerase chain reaction (qPCR) assay, as well as for the known respiratory pathogens Mycoplasma agassizii Brown et al., 2001 and Mycoplasma testudineum Brown et al., 2004. We found very little disease and suggest that P. testudinis is a prevalent, commensal microbe in these Mojave Desert Tortoise populations, and its quantification may be a tool to study natural fluctuations in microbe levels in Mojave Desert Tortoise respiratory tracts. Our analyses showed that both the potential for inflammatory responses and microbe levels are highest in the spring for healthy Mojave Desert Tortoises, when lymphocyte levels are lowest. The genetic and statistical tools that we used are easily applicable to other wildlife systems and provide the necessary data to quantify species-wide trends in health and test hypotheses pertinent to host–microbe dynamics.
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Affiliation(s)
- F.C. Sandmeier
- Biology Department, Colorado State University–Pueblo, 2200 Bonforte Boulevard, Pueblo, CO 81001, USA
| | - K.L. Leonard
- Biology Department, Colorado State University–Pueblo, 2200 Bonforte Boulevard, Pueblo, CO 81001, USA
| | - C.R. Tracy
- Biology Department, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV 89557, USA
| | - K.K. Drake
- U.S. Geological Survey, 160 North Stephanie Street, Henderson, NV 89074, USA
| | - T.E. Esque
- U.S. Geological Survey, 160 North Stephanie Street, Henderson, NV 89074, USA
| | - K. Nussear
- Geography Department, University of Nevada, Reno, 1664 North Virginia Street, Reno, NV 89557, USA
| | - J.M. Germano
- New Zealand Department of Conservation, 18 Manners Street, Wellington 6011, New Zealand
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Ellison S, Rovito S, Parra-Olea G, Vásquez-Almazán C, Flechas SV, Bi K, Vredenburg VT. The Influence of Habitat and Phylogeny on the Skin Microbiome of Amphibians in Guatemala and Mexico. MICROBIAL ECOLOGY 2019; 78:257-267. [PMID: 30467714 DOI: 10.1007/s00248-018-1288-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Accepted: 11/06/2018] [Indexed: 06/09/2023]
Abstract
Microbial symbionts are increasingly recognized as playing a critical role in organismal health across a wide range of hosts. Amphibians are unique hosts in that their skin helps to regulate the exchange of water, ions, and gases, and it plays an active role in defense against pathogens through the synthesis of anti-microbial peptides. The microbiome of amphibian skin includes a diverse community of bacteria known to defend against pathogens, including the global pandemic lineage of Batrachochytrium dendrobatidis associated with mass amphibian die-offs. The relative influence of host phylogeny and environment in determining the composition of the amphibian skin microbiome remains poorly understood. We collected skin swabs from montane amphibians in Mexico and Guatemala, focusing on two genera of plethodontid salamanders and one genus of frogs. We used high throughput sequencing to characterize the skin bacterial microbiome and tested the impact of phylogeny and habitat on bacterial diversity. Our results show that phylogenetic history strongly influences the diversity and community structure of the total bacterial microbiome at higher taxonomic levels (between orders), but on lower scales (within genera and species), the effect of habitat predominates. These results add to a growing consensus that habitat exerts a strong effect on microbiome structure and composition, particularly at shallow phylogenetic scales.
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Affiliation(s)
- Silas Ellison
- Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA, 94132, USA
| | - Sean Rovito
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, 94720, USA.
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Km 9.6 Libramiento Norte Carretera Irapuato-León, 36824, Irapuato, Guanajuato, Mexico.
| | - Gabriela Parra-Olea
- Departamento de Zoología, Insituto de Biología, Universidad Nacional Autónoma de México, CP04510, México, DF, Mexico
| | - Carlos Vásquez-Almazán
- Museo de Historia Natural y Escuela de Biología, Universidad de San Carlos, Guatemala, Guatemala
| | - Sandra V Flechas
- Department of Biological Sciences, Universidad de los Andes, AA 4976, Bogotá, Colombia
- Instituto de Investigación de Recursos Biológicos Alexander von Humboldt, Bogotá, Colombia
| | - Ke Bi
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, 94720, USA
- Computational Genomics Resource Laboratory, California Institute for Quantitative Biosciences University of California, Berkeley, CA, 94720, USA
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA, 94132, USA
- Museum of Vertebrate Zoology, University of California, Berkeley, CA, 94720, USA
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