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.
Highlights
The fungal pathogen Batrachochytrium dendrobatidis has caused the severe decline or extinction of over 200 amphibian species [1, 2]
Attempts to implement bioaugmentations in wild populations have often been hampered by limited persistence of target bacterial strains over time [7, 10, 11], which highlights the importance of understanding the fundamental community ecology of skin microbial communities, in particular how they fluctuate through time under natural conditions
In order to check the assumptions of analysis of variance (ANOVA), Shapiro–Wilk tests were used to test for normality, and Bartlett tests and Figner–Killeen tests were used to test for homogeneity of variances
Summary
The fungal pathogen Batrachochytrium dendrobatidis has caused the severe decline or extinction of over 200 amphibian species [1, 2]. Attempts to implement bioaugmentations in wild populations have often been hampered by limited persistence of target bacterial strains over time [7, 10, 11], which highlights the importance of understanding the fundamental community ecology of skin microbial communities, in particular how they fluctuate through time under natural conditions Our knowledge of such temporal dynamics is currently limited, especially in the skin microbiome of animal species in wild populations. Two other recent studies have investigated temporal stability in the skin microbiome of individual newts in semi-natural settings (mesocosms or field enclosures): one study found that the skin microbial community structure of Eastern redspotted newts was relatively stable across seasons and years, but that environmental disturbance significantly impacted community structure, richness, evenness, and phylogenetic diversity [15]. Variability: Variation in bacterial communities through time, defined as the average UniFrac distance between samples collected from an individual frog
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
