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Climate change and human activities escalate the frequency and intensity of wildfires, threatening amphibian habitats and survival; yet, research on these impacts remains limited. Wildfire ash alters water quality, introduces contaminants, and may disrupt microbial communities, impacting gut and skin microbiota; however, the effects on gut and skin microbiota remain unclear. Rana dybowskii were exposed to five concentrations (0 g L-1, 1.25 g L-1, 2.5 g L-1, 5 g L-1, and 10 g L-1) of aqueous extracts of wildfire ashes (AEAs) for 30 days to assess AEAs' metal content, survival, and microbiota diversity via Illumina sequencing. Our results showed that the major elements in ash were Ca > K > Mg > Al > Fe > Na > Mn, while in AEA they were K > Ca > Na > Mg > As > Al > Cu. A significant decrease in amphibian survival rates with increased AEA concentration was shown. The beta diversity analysis revealed distinct shifts in microbiota composition. Notably, bacterial genera associated with potential health risks showed increased abundance in skin microbiota, emphasising the potential for ash exposure to affect amphibian health. Functional prediction analyses revealed significant shifts in metabolic pathways related to health and disease, indicating that wildfire ash exposure may influence amphibian health through changes in microbial functions. This study highlights the urgent need for strategies to mitigate wildfire ash impacts on amphibians, as it significantly alters microbiota and affects their survival and health. [Display omitted] • Wildfire ash alters water quality, introducing contaminants to amphibian habitats. • R. dybowskii survival significantly declines with increased AEA concentrations. • Gut microbiota diversity changes after ash exposure, revealing resilience and vulnerability. • Skin microbiota shows robustness, with minor changes in composition after ash exposure. • Exposure influences metabolic pathways, suggesting health implications for amphibians. [ABSTRACT FROM AUTHOR]

Antibiotics are key in combating bacterial infections and halting disease spread, yet their effects on amphibian gut microbiomes remain poorly understood. Amphibian survival depends on their skin microbiota. Drugs used to treat amphibians may affect gut microbiota but has yet to have unexplored impacts on skin microbiota. We used Illumina sequencing to analyze the cutaneous (C) and gut (G) microbiota of healthy (H) frogs and diseased (D) frogs treated with antibiotics and evaluate their functional characteristics. The result showed that antibiotics lowered gut microbiota alpha diversity but not skin microbiota. Bray-Curtis and UniFrac measures demonstrate the significant variations in skin and gut microbiota between healthy and antibiotic-treated frogs. Bacteroidota, Firmicutes, and Proteobacteria predominated in DC and HC; Proteobacteria, Firmicutes, and Bacteroidota dominated DG and HG. Linear discriminant analysis and effect size (LEfSe) analysis identified specific bacterial taxa enriched in antibiotic-treated versus healthy frogs. Maximum likelihood (ML) analysis revealed close evolutionary relationships among certain bacterial taxa. Functional predictions indicated significant differences in metabolic pathways between groups, and BugBase analysis showed variations in bacterial phenotypes, suggesting altered microbial functions following antibiotic treatment. Antibiotic treatment in frogs significantly altered gut microbiota diversity and impacts functional pathways in both gut and skin microbiota without affecting skin microbiota alpha diversity. Antibiotics' complex effects on frog microbiota showed R. dybowskii 's delicate balance between therapeutic advantages and ecological changes, which might affect conservation and health initiatives. • New insights on antibiotics' effect on amphibian microbiota. • Antibiotics alter gut but not skin microbiota diversity. • Identified microbes linked to health and disease states. • Analyzed functional changes in microbiota post-antibiotics. [ABSTRACT FROM AUTHOR]