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Jones KR, Belden LK, Hughey MC. Priority effects alter microbiome composition and increase abundance of probiotic taxa in treefrog tadpoles. Appl Environ Microbiol 2024; 90:e0061924. [PMID: 38757977 DOI: 10.1128/aem.00619-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Accepted: 04/21/2024] [Indexed: 05/18/2024] Open
Abstract
Host-associated microbial communities, like other ecological communities, may be impacted by the colonization order of taxa through priority effects. Developing embryos and their associated microbiomes are subject to stochasticity during colonization by bacteria. For amphibian embryos, often developing externally in bacteria-rich environments, this stochasticity may be particularly impactful. For example, the amphibian microbiome can mitigate lethal outcomes from disease for their hosts; however, this may depend on microbiome composition. Here, we examined the assembly of the bacterial community in spring peeper (Pseudacris crucifer) embryos and tadpoles. First, we reared embryos from identified mating pairs in either lab or field environments to examine the relative impact of environment and parentage on embryo and tadpole bacterial communities. Second, we experimentally inoculated embryos to determine if priority effects (i) could be used to increase the relative abundance of Janthinobacterium lividum, an amphibian-associated bacteria capable of preventing fungal infection, and (ii) would lead to observed differences in the relative abundances of two closely related bacteria from the genus Pseudomonas. Using 16S rRNA gene amplicon sequencing, we observed differences in community composition based on rearing location and parentage in embryos and tadpoles. In the inoculation experiment, we found that priority inoculation could increase the relative abundance of J. lividum, but did not find that either Pseudomonas isolate was able to prevent colonization by the other when given priority. These results highlight the importance of environmental source pools and parentage in determining microbiome composition, while also providing novel methods for the administration of a known amphibian probiotic. IMPORTANCE Harnessing the functions of host-associated bacteria is a promising mechanism for managing disease outcomes across different host species. In the case of amphibians, certain frog-associated bacteria can mitigate lethal outcomes of infection by the fungal pathogen Batrachochytrium dendrobatidis. Successful probiotic applications require knowledge of community assembly and an understanding of the ecological mechanisms that structure these symbiotic bacterial communities. In our study, we show the importance of environment and parentage in determining bacterial community composition and that community composition can be influenced by priority effects. Further, we provide support for the use of bacterial priority effects as a mechanism to increase the relative abundance of target probiotic taxa in a developing host. While our results show that priority effects are not universally effective across all host-associated bacteria, our ability to increase the relative abundance of specific probiotic taxa may enhance conservation strategies that rely on captive rearing of endangered vertebrates.
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Affiliation(s)
- Korin Rex Jones
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Lisa K Belden
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Myra C Hughey
- Department of Biology, Vassar College, Poughkeepsie, New York, USA
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White A, Giannetto M, Mulla L, Del Rosario A, Lim T, Culver E, Timmer M, Bushell J, Lambert MR, Hernández-Gómez O. Bacterial communities of the threatened Western Pond Turtle may be impacted by land use. FEMS Microbiol Ecol 2023; 99:fiad143. [PMID: 37950563 DOI: 10.1093/femsec/fiad143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 11/05/2023] [Accepted: 11/08/2023] [Indexed: 11/12/2023] Open
Abstract
As semi-aquatic species that use both terrestrial and aquatic habitats, freshwater turtles and their microbial communities are especially sensitive to the impacts of habitat disturbance. In this study, we use 16S rRNA amplicon sequencing to characterize the shell and cloacal bacterial communities of turtles in the San Francisco Bay Area. We captured western pond turtles (Actinemys/Emys marmorata) across eight sites located in urban and rural environments, along with invasive red-eared sliders (Trachemys scripta elegans). We assessed differences in western pond turtle bacterial communities diversity/composition between shell and cloacal samples and evaluated how alpha/beta diversity metrics were influenced by habitat quality. We found phylum-level bacterial taxonomic turnover in the bacterial communities of western pond turtles relative to the host tissue substrate samples. Our findings indicate that location identity elicits a high degree of lower-level (i.e. species/genus) bacterial taxonomic turnover. Further, we found that samples originating from good quality habitat had poorer shell bacterial communities but more diverse cloacal ones. The shell bacterial communities of red-eared sliders overlapped with those western pond turtles suggesting the existence of microbial dispersal between these two species. Our results add to our current understanding of turtle symbiont microbial ecology by establishing patterns of bacterial symbiont variation in an urban to rural gradient.
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Affiliation(s)
- Alison White
- Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, CA 94901, United States
| | - Madison Giannetto
- Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, CA 94901, United States
| | - Lubna Mulla
- Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, CA 94901, United States
| | - Amber Del Rosario
- Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, CA 94901, United States
| | - Tammy Lim
- East Bay Regional Parks, Oakland, CA 94605, United States
| | - Edward Culver
- East Bay Regional Parks, Oakland, CA 94605, United States
| | - Matthew Timmer
- Land Trust of Santa Cruz County, Santa Cruz, CA 95060, United States
| | - Jessie Bushell
- San Francisco Zoo and Gardens, San Francisco, CA 94132, United States
| | - Max R Lambert
- Washington Department of Fish and Wildlife, Olympia, WA 98501, United States
| | - Obed Hernández-Gómez
- Department of Natural Sciences and Mathematics, Dominican University of California, San Rafael, CA 94901, United States
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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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Dallas JW, Warne RW. Captivity and Animal Microbiomes: Potential Roles of Microbiota for Influencing Animal Conservation. MICROBIAL ECOLOGY 2023; 85:820-838. [PMID: 35316343 DOI: 10.1007/s00248-022-01991-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 03/07/2022] [Indexed: 05/04/2023]
Abstract
During the ongoing biodiversity crisis, captive conservation and breeding programs offer a refuge for species to persist and provide source populations for reintroduction efforts. Unfortunately, captive animals are at a higher disease risk and reintroduction efforts remain largely unsuccessful. One potential factor in these outcomes is the host microbiota which includes a large diversity and abundance of bacteria, fungi, and viruses that play an essential role in host physiology. Relative to wild populations, the generalized pattern of gut and skin microbiomes in captivity are reduced alpha diversity and they exhibit a significant shift in community composition and/or structure which often correlates with various physiological maladies. Many conditions of captivity (antibiotic exposure, altered diet composition, homogenous environment, increased stress, and altered intraspecific interactions) likely lead to changes in the host-associated microbiome. To minimize the problems arising from captivity, efforts can be taken to manipulate microbial diversity and composition to be comparable with wild populations through methods such as increasing dietary diversity, exposure to natural environmental reservoirs, or probiotics. For individuals destined for reintroduction, these strategies can prime the microbiota to buffer against novel pathogens and changes in diet and improve reintroduction success. The microbiome is a critical component of animal physiology and its role in species conservation should be expanded and included in the repertoire of future management practices.
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Affiliation(s)
- Jason W Dallas
- Department of Biological Sciences, Southern Illinois University, 1125 Lincoln Drive, Carbondale, IL, 62901, USA.
| | - Robin W Warne
- Department of Biological Sciences, Southern Illinois University, 1125 Lincoln Drive, Carbondale, IL, 62901, USA
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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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Ophidiomyces ophidiicola detection and infection: a global review on a potential threat to the world’s snake populations. EUR J WILDLIFE RES 2022. [DOI: 10.1007/s10344-022-01612-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
AbstractOphidiomyces ophidiicola (Oo) is one of the most relevant fungal pathogens for snakes. It is the etiological agent of ophidiomycosis, an emerging disease causing dysecdysis, skin abnormalities, crusting cutaneous lesions, and ulcerations. Despite this major tegumentary “tropism”, Oo infection can be systemic and it is capable of inducing visceral lesions. Moreover, ophidiomycosis may lead to abnormalities of reproductive physiology, hunting behavior, and thermoregulation, thus increasing the risks of sublethal effects and predation on affected snakes. Oo seems horizontally transmitted and can induce postnatal mortality. This article reviews published data on Oo detection and infection in all snake species in countries around the world and categorizes these data using new classification parameters. The presence of this fungus has been recorded in 11 states (considering the USA as a whole); however, in four states, the mycosis has only been reported in snakes held in captivity. Detection and/or infection of Oo has been ascertained in 62 snake species, divided into nine families. The taxa have been categorized with diagnostic criteria in order to report, for each species, the highest rank of categorization resulting from all cases. Therefore, 20 species have been included within the class “Ophidiomycosis and Oo shedder”, 11 within “Ophidiomycosis”, 16 in “Apparent ophidiomycosis”, and 15 within “Ophidiomyces ophidiicola present”. We also discuss the significance and limits of case classifications and Oo’s impact on wild populations, and we suggest methods for preliminary surveillance. Standardized methods, interdisciplinary studies, and cooperation between various research institutions may facilitate further Oo screening studies, elucidate the unclear aspects of the disease, and protect ophidiofauna from this emerging threat at the global level.
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PARASITOLOGIC AND PATHOLOGIC STUDY OF FREE-RANGING SOUTH AMERICAN RATTLESNAKES ( CROTALUS DURISSUS TERRIFICUS) IN BRAZIL. J Zoo Wildl Med 2022; 53:515-527. [DOI: 10.1638/2021-0065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/01/2022] [Indexed: 11/21/2022] Open
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Comparative Assessment of Computed Tomography and Magnetic Resonance Imaging of Spider Morph and Wild Type Ball Pythons (Python regius) for Evaluation of the Morphological Correlate of Wobble Syndrome. J Comp Pathol 2022; 196:26-40. [DOI: 10.1016/j.jcpa.2022.05.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 05/09/2022] [Accepted: 05/26/2022] [Indexed: 11/18/2022]
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Inhibitory Bacterial Diversity and Mucosome Function Differentiate Susceptibility of Appalachian Salamanders to Chytrid Fungal Infection. Appl Environ Microbiol 2022; 88:e0181821. [PMID: 35348389 PMCID: PMC9040618 DOI: 10.1128/aem.01818-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Mucosal defenses are crucial in animals for protection against pathogens and predators. Host defense peptides (antimicrobial peptides, AMPs) as well as skin-associated microbes are key components of mucosal immunity, particularly in amphibians. We integrate microbiology, molecular biology, network-thinking, and proteomics to understand how host and microbially derived products on amphibian skin (referred to as the mucosome) serve as pathogen defenses. We studied defense mechanisms against chytrid pathogens, Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal), in four salamander species with different Batrachochytrium susceptibilities. Bd infection was quantified using qPCR, mucosome function (i.e., ability to kill Bd or Bsal zoospores in vitro), skin bacterial communities using 16S rRNA gene amplicon sequencing, and the role of Bd-inhibitory bacteria in microbial networks across all species. We explored the presence of candidate-AMPs in eastern newts and red-backed salamanders. Eastern newts had the highest Bd prevalence and mucosome function, while red-back salamanders had the lowest Bd prevalence and mucosome function, and two-lined salamanders and seal salamanders were intermediates. Salamanders with highest Bd infection intensity showed greater mucosome function. Bd infection prevalence significantly decreased as putative Bd-inhibitory bacterial richness and relative abundance increased on hosts. In co-occurrence networks, some putative Bd-inhibitory bacteria were found as hub-taxa, with red-backs having the highest proportion of protective hubs and positive associations related to putative Bd-inhibitory hub bacteria. We found more AMP candidates on salamanders with lower Bd susceptibility. These findings suggest that salamanders possess distinct innate mechanisms that affect chytrid fungi. IMPORTANCE How host mucosal defenses interact, and influence disease outcome is critical in understanding host defenses against pathogens. A more detailed understanding is needed of the interactions between the host and the functioning of its mucosal defenses in pathogen defense. This study investigates the variability of chytrid susceptibility in salamanders and the innate defenses each species possesses to mediate pathogens, thus advancing the knowledge toward a deeper understanding of the microbial ecology of skin-associated bacteria and contributing to the development of bioaugmentation strategies to mediate pathogen infection and disease. This study improves the understanding of complex immune defense mechanisms in salamanders and highlights the potential role of the mucosome to reduce the probability of Bd disease development and that putative protective bacteria may reduce likelihood of Bd infecting skin.
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Host microbiome responses to the Snake Fungal Disease pathogen (Ophidiomyces ophidiicola) are driven by changes in microbial richness. Sci Rep 2022; 12:3078. [PMID: 35197501 PMCID: PMC8866498 DOI: 10.1038/s41598-022-07042-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 02/07/2022] [Indexed: 11/24/2022] Open
Abstract
Dermatophytic pathogens are a source of disturbance to the host microbiome, but the temporal progression of these disturbances is unclear. Here, we determined how Snake Fungal Disease, caused by Ophidiomyces ophidiicola, resulted in disturbance to the host microbiome. To assess disease effects on the microbiome, 22 Common Watersnakes (Nerodia sipedon) were collected and half were inoculated with O. ophidiicola. Epidermal swabs were collected weekly for use in microbiome and pathogen load characterization. For the inoculated treatment only, we found a significant effect of disease progression on microbial richness and Shannon diversity consistent with the intermediate disturbance hypothesis. When explicitly accounting for differences in assemblage richness, we found that β-diversity among snakes was significantly affected by the interaction of time and treatment group, with assemblages becoming more dissimilar across time in the inoculated, but not the control group. Also, differences between treatments in average microbiome composition became greater with time, but this interactive effect was not evident when accounting for assemblage richness. These results suggest that changes in composition of the host microbiome associated with disease largely occur due to changes in microbial richness related to disease progression.
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OPTIMIZING THE PHARMACODYNAMICS AND EVALUATING CARDIOGENIC EFFECTS OF THE INJECTABLE ANESTHETIC ALFAXALONE IN PRAIRIE RATTLESNAKES ( CROTALUS VIRIDIS). J Zoo Wildl Med 2022; 52:1105-1112. [PMID: 34998279 DOI: 10.1638/2021-0056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2021] [Indexed: 11/21/2022] Open
Abstract
North American vipers are commonly housed in zoological institutions or studied as free-ranging populations. Because of their venomous predatory and defensive mechanism, sedation or anesthesia is frequently employed to facilitate safe handling and medical procedures, especially of the head. A new formulation of alfaxalone with proprietary preservatives was recently approved and indexed for 28-d use post-vial puncture. Pharmacodynamic effects of alfaxalone in its prior formulation have been researched in nonvenomous species, but the optimal dose and route of administration in vipers have not been reported. In part one, 10 prairie rattlesnakes (Crotalus viridis) participated in a complete four-route crossover study evaluating 20 mg/kg alfaxalone administered intracoelomically (ICo), SC cranial to the heart, IM cranial to the heart, and IV in the ventral coccygeal vein. HR significantly decreased from baseline during IV (P= 0.024), IM (P= 0.024), and SC (P= 0.028) administration. Respiratory rate significantly decreased following alfaxalone delivered IV (P = 0.027). Time to first effects was significantly faster in IV compared with IM (P= 0.01), SC (P= 0.001), and ICo (P= 0.036). All IV and IM administrations resulted in deep sedation, but 70% of the IV and 10% of the IM sedation events resulted in apnea and required intermittent positive ventilation via endotracheal tube. Fifty percent of the ICo sedation events and 10% of the SC sedation events did not result in sedation. One successful SC sedation event resulted in apnea. In part two, echocardiograms were performed in the same rattlesnakes at baseline and at maximum effect of sedation with 20 mg/kg alfaxalone administered IM. Cardiac contractility and output were unaffected. Administration of alfaxalone at 20 mg/kg IM cranial to the heart should facilitate safe handling and minimally invasive procedures in prairie rattlesnakes and related species.
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Godwin CD, Walker DM, Romer AS, Grajal-Puche A, Grisnik M, Goessling JM, Perkin JS, Murray CM. Testing the febrile response of snakes inoculated with Ophidiomyces ophidiicola, the causative agent of snake fungal disease. J Therm Biol 2021; 100:103065. [PMID: 34503803 DOI: 10.1016/j.jtherbio.2021.103065] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 07/09/2021] [Accepted: 08/01/2021] [Indexed: 11/28/2022]
Abstract
Snake Fungal Disease (SFD) negatively impacts wild snake populations in the eastern United States and Europe. Ophidiomyces ophidiicola causes SFD and manifests clinically by the formation of heterophilic granulomas around the mouth and eyes, weight loss, impaired vision, and sometimes death. Field observations have documented early seasonal basking behaviors in severely infected snakes, potentially suggesting induction of a behavioral febrile response to combat the mycosis. This study tested the hypothesis that snakes inoculated with Ophidiomyces ophidiicola would seek elevated basking temperatures to control body temperature and behaviorally induce a febrile response. Eastern ribbon snakes (Thamnophis saurita, n = 29) were experimentally or sham inoculated with O. ophidiicola. Seven days after inoculation, snakes were tested on a thermal gradient and the internal body temperature and substrate temperature of each snake was recorded over time. Quantitative PCR was used when snakes arrived, during pre-inoculation, and post-inoculation to test snakes for the presence of O. ophidiicola. Some snakes arrived with O. ophidiicola and were subsequently inoculated, allowing for an assessment of secondary exposure effects. Snake thermoregulatory behavior was compared between 1) O. ophidiicola inoculated vs. sham inoculated treatments, 2) infected vs. disease negative groups, and 3) disease naïve vs. pre-exposed immune response categories. Neither internal nor substrate temperatures differed among initially prescribed, and qPCR recovered disease states, although infected snakes tended to reach a preferred body temperature faster than disease negative snakes. Snakes experiencing their first exposure (disease naïve) sought higher substrate temperatures than snakes experiencing their second exposure (pre-exposed). Here, we recover no evidence for behaviorally induced fever in snakes with SFD but do elucidate a febrile immune response associated with secondary exposure.
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Affiliation(s)
- Cody Davis Godwin
- Tennessee Technological University, Department of Biology, 1 William L Jones Dr, Cookeville, TN, 38505, USA
| | - Donald M Walker
- Middle Tennessee State University, Department of Biology, 1301 E Main St, Murfreesboro, TN, 37132, USA.
| | - Alexander S Romer
- Middle Tennessee State University, Department of Biology, 1301 E Main St, Murfreesboro, TN, 37132, USA
| | - Alejandro Grajal-Puche
- Middle Tennessee State University, Department of Biology, 1301 E Main St, Murfreesboro, TN, 37132, USA; Northern Arizona University, Department of Biological Sciences, Flagstaff, AZ, 86011, USA
| | - Matthew Grisnik
- Middle Tennessee State University, Department of Biology, 1301 E Main St, Murfreesboro, TN, 37132, USA
| | | | - Joshua S Perkin
- Department of Ecology and Conservation Biology, Texas A&M University, College Station, TX, 77843, USA
| | - Christopher M Murray
- Tennessee Technological University, Department of Biology, 1 William L Jones Dr, Cookeville, TN, 38505, USA; Southeastern Louisiana University, Department of Biological Sciences, Hammond, LA, 70402, USA
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Brockmann M, Aupperle-Lellbach H, Gentil M, Heusinger A, Müller E, Marschang RE, Pees M. Challenges in microbiological identification of aerobic bacteria isolated from the skin of reptiles. PLoS One 2020; 15:e0240085. [PMID: 33075077 PMCID: PMC7571677 DOI: 10.1371/journal.pone.0240085] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/19/2020] [Indexed: 12/17/2022] Open
Abstract
INTRODUCTION Bacterial pathogens are often involved in dermatitis in reptiles. Exact identification of reptile-specific but otherwise uncommon bacterial species may be challenging. However, identification is crucial to evaluate the importance of the detected bacterial species. OBJECTIVE The aim of this study was to assess the number of aerobic bacterial isolates cultured from skin-derived samples of reptiles which were not reliably identified by Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS), and to determine their identity. MATERIAL AND METHODS Routine bacterial diagnostics were performed on 235 skin samples, and 417 bacterial isolates were analysed by MALDI-TOF MS. The isolates were grouped into categories based on their first score: category I (≥ 2.00), category II (≥ 1.70 and < 2.00), and category III (< 1.70). Isolates from category III were further investigated by 16S rRNA gene sequencing and the following criteria were applied: query cover 100%, e-value rounded to 0.0 and sequence identity (%) > 98.00% for genus identification, and > 99.00% for species identification. RESULTS The majority of bacterial isolates were in category I (85.1%) or category II (8.4%). In category III (6.5%) results achieved at first by MALDI-TOF MS corresponded to the results of the molecular analysis in 8.0% of isolates at the species level and in 24.0% at the genus level. Bacterial isolates classified as category III were heterogenic in genus (e.g. Chryseobacterium, Devriesea, Pseudomonas, Staphylococcus, Uruburuella), and some have only been described in reptiles so far. CONCLUSIONS Most of the aerobic bacterial isolates cultured from reptile skin achieved high scores by MALDI-TOF MS. However, in the majority of category III isolates MALDI-TOF MS results were different from those of the molecular analysis. This strengthens the need to carefully examine low-scored results for plausibility and to be familiar with the occurrence and morphology of relevant reptile-specific bacterial species (e.g. Devriesea agamarum) as well as with the limits of the database used.
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MESH Headings
- Animals
- Bacteria, Aerobic/chemistry
- Bacteria, Aerobic/genetics
- Bacteria, Aerobic/isolation & purification
- Gram-Negative Bacteria/genetics
- Gram-Negative Bacteria/isolation & purification
- Gram-Negative Bacteria/metabolism
- Gram-Positive Bacteria/genetics
- Gram-Positive Bacteria/isolation & purification
- Gram-Positive Bacteria/metabolism
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 16S/metabolism
- Reptiles/microbiology
- Skin/microbiology
- Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
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Affiliation(s)
| | | | | | | | | | | | - Michael Pees
- Clinic for Birds and Reptiles, University of Leipzig, Leipzig, Germany
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14
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Ross AA, Rodrigues Hoffmann A, Neufeld JD. The skin microbiome of vertebrates. MICROBIOME 2019; 7:79. [PMID: 31122279 PMCID: PMC6533770 DOI: 10.1186/s40168-019-0694-6] [Citation(s) in RCA: 105] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Accepted: 05/08/2019] [Indexed: 05/05/2023]
Abstract
The skin constitutes the primary physical barrier between vertebrates and their external environment. Characterization of skin microorganisms is essential for understanding how a host evolves in association with its microbial symbionts, modeling immune system development, diagnosing illnesses, and exploring the origins of potential zoonoses that affect humans. Although many studies have characterized the human microbiome with culture-independent techniques, far less is known about the skin microbiome of other mammals, amphibians, birds, fish, and reptiles. The aim of this review is to summarize studies that have leveraged high-throughput sequencing to better understand the skin microorganisms that associate with members of classes within the subphylum Vertebrata. Specifically, links will be explored between the skin microbiome and vertebrate characteristics, including geographic location, biological sex, animal interactions, diet, captivity, maternal transfer, and disease. Recent literature on parallel patterns between host evolutionary history and their skin microbial communities, or phylosymbiosis, will also be analyzed. These factors must be considered when designing future microbiome studies to ensure that the conclusions drawn from basic research translate into useful applications, such as probiotics and successful conservation strategies for endangered and threatened animals.
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Affiliation(s)
- Ashley A Ross
- University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada
- Present address: Ontario Veterinary College, University of Guelph, 419 Gordon St, Guelph, Ontario, N1G 2W1, Canada
| | - Aline Rodrigues Hoffmann
- Department of Veterinary Pathobiology, College of Veterinary Medicine & Biomedical Sciences, Texas A&M University, 660 Raymond Stotzer Pkwy, College Station, TX, USA
| | - Josh D Neufeld
- University of Waterloo, 200 University Avenue West, Waterloo, Ontario, N2L 3G1, Canada.
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15
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Walker DM, Leys JE, Grisnik M, Grajal-Puche A, Murray CM, Allender MC. Variability in snake skin microbial assemblages across spatial scales and disease states. ISME JOURNAL 2019; 13:2209-2222. [PMID: 31065028 PMCID: PMC6776063 DOI: 10.1038/s41396-019-0416-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 04/10/2019] [Accepted: 04/12/2019] [Indexed: 02/07/2023]
Abstract
Understanding how biological patterns translate into functional processes across different scales is a central question in ecology. Within a spatial context, extent is used to describe the overall geographic area of a study, whereas grain describes the overall unit of observation. This study aimed to characterize the snake skin microbiota (grain) and to determine host–microbial assemblage–pathogen effects across spatial extents within the Southern United States. The causative agent of snake fungal disease, Ophidiomyces ophiodiicola, is a fungal pathogen threatening snake populations. We hypothesized that the skin microbial assemblage of snakes differs from its surrounding environment, by host species, spatial scale, season, and in the presence of O. ophiodiicola. We collected snake skin swabs, soil samples, and water samples across six states in the Southern United States (macroscale extent), four Tennessee ecoregions (mesoscale extent), and at multiple sites within each Tennessee ecoregion (microscale extent). These samples were subjected to DNA extraction and quantitative PCR to determine the presence/absence of O. ophiodiicola. High-throughput sequencing was also utilized to characterize the microbial communities. We concluded that the snake skin microbial assemblage was partially distinct from environmental microbial communities. Snake host species was strongly predictive of the skin microbiota at macro-, meso-, and microscale spatial extents; however, the effect was variable across geographic space and season. Lastly, the presence of the fungal pathogen O. ophiodiicola is predictive of skin microbial assemblages across macro- and meso-spatial extents, and particular bacterial taxa associate with O. ophiodiicola pathogen load. Our results highlight the importance of scale regarding wildlife host–pathogen–microbial assemblage interactions.
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Affiliation(s)
- Donald M Walker
- Toxicology and Disease Group, Biology Department, Middle Tennessee State University, PO Box 60, Murfreesboro, TN, USA.
| | - Jacob E Leys
- Department of Biology, Tennessee Technological University, Cookeville, TN, USA
| | - Matthew Grisnik
- Toxicology and Disease Group, Biology Department, Middle Tennessee State University, PO Box 60, Murfreesboro, TN, USA
| | - Alejandro Grajal-Puche
- Toxicology and Disease Group, Biology Department, Middle Tennessee State University, PO Box 60, Murfreesboro, TN, USA
| | | | - Matthew C Allender
- Wildlife Epidemiology Laboratory, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Champaign, IL, USA
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16
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Weitzman CL, Gibb K, Christian K. Skin bacterial diversity is higher on lizards than sympatric frogs in tropical Australia. PeerJ 2018; 6:e5960. [PMID: 30479906 PMCID: PMC6240339 DOI: 10.7717/peerj.5960] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 10/18/2018] [Indexed: 12/24/2022] Open
Abstract
Animal skin acts as a barrier between the organism and its environment and provides the first line of defense against invading pathogens. Thus, skin surfaces harbor communities of microbes that are interacting with both the host and its environment. Amphibian skin bacteria form distinct communities closely tied to their host species, but few studies have compared bacterial communities between amphibians and other, non-amphibian sympatric animals. Notably, skin microbes on reptiles have gained little attention. We used next-generation sequencing technology to describe bacterial communities on the skin of three lizard species and compared them to bacteria on six cohabiting frog species in the Northern Territory of Australia. We found bacterial communities had higher richness and diversity on lizards than frogs, with different community composition between reptiles and amphibians and among species. Core bacteria on the three lizard species overlapped by over 100 operational taxonomic units. The bacterial communities were similar within species of frogs and lizards, but the communities tended to be more similar between lizard species than between frog species and when comparing lizards with frogs. The diverse bacteria found on lizards invites further questions on how and how well reptiles interact with microorganisms through their scaly skin.
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Affiliation(s)
- Chava L. Weitzman
- Independent Researcher, Millburn, NJ, United States of America
- Department of Biology, University of Nevada—Reno, Reno, NV, United States of America
| | - Karen Gibb
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Casuarina, Northern Territory, Australia
| | - Keith Christian
- Research Institute for the Environment and Livelihoods, Charles Darwin University, Casuarina, Northern Territory, Australia
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17
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Snake fungal disease alters skin bacterial and fungal diversity in an endangered rattlesnake. Sci Rep 2018; 8:12147. [PMID: 30108369 PMCID: PMC6092386 DOI: 10.1038/s41598-018-30709-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Accepted: 08/05/2018] [Indexed: 02/06/2023] Open
Abstract
Snake Fungal Disease (SFD), caused by Ophidiomyces ophiodiicola, is the most recently described fungal disease afflicting wildlife populations across North America and Europe. It has been proposed as a significant conservation threat yielding high mortality and yet much its ecology is unknown. We collected 144 skin swabs from Eastern Massasaugas (Sistrurus catenatus) in 2015 and 2016 to determine document ongoing prevalence and assess differences in microbial assemblages between positive and negative individuals. Alpha diversity of fungi was reduced in SFD positive animals, while beta diversity identified distinct assemblages of microbes between SFD-positive and -negative samples. Ophidiomyces was present on the skin of affected animals, even on body sites distant to lesions indicating that the microbiome on entire surface of the skin is altered. Ophidiomyces was not detected in any non-SFD snake. There were smaller, but significant, influences of year sampled. Bacterial genera Janthinobacterium and Serratia were significantly increased in SFD snakes, while Xylanimicrobium, Cellulosimicrobium, and Rhodococcus were the only bacterial taxa significantly reduced. The relative abundance of fungi within the orders Pleosporales and Canopdiales was reduced in SFD-positive samples, though Pyrenochaetopsis pratorum was the only species found to differ significantly. This is the first study to determine the impact that this fungal pathogen has on the skin microbiome.
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