Unraveling the disease pyramid: the role of environmental micro-eukaryotes in amphibian resistance to the deadly fungal pathogen <i>Batrachochytrium dendrobatidis</i>
Bibliographic record
Abstract
ABSTRACT The disease pyramid conceptualizes the predictors of host infection risk, linking the host, the pathogen, environmental conditions, and both host and environmental microbiomes. However, the importance of the interaction between environmental and host-associated microbiomes in shaping infectious disease dynamics remains poorly understood. While the majority of studies have focused on bacteria, the role of micro-eukaryotes has been seldom investigated. Here, we explore three axes of the disease pyramid using an 18S rRNA gene metabarcoding approach to analyze the micro-eukaryotic assemblages of biofilm, water, and skin samples from three European amphibian species. Skin bacterial communities of the investigated amphibian populations have already been shown to be impacted by the presence of the lethal fungal pathogen Batrachochytrium dendrobatidis ( Bd ), with a higher abundance of protective bacteria in infected populations and a greater environmental microbial contribution to the skin microbiota in Bd -positive lakes. Here, we explored the relationships between the micro-eukaryotic skin communities of these tadpole populations with their surrounding environment. Tadpoles were sampled at 22 mountain lakes located in the Pyrenees (France), 8 of which harbored amphibian populations infected by Bd . We found that biofilms from Bd -negative lakes had higher environmental micro-eukaryotic diversity and a greater abundance of putative anti- Bd fungi, both in the environment and on the skin microbiota of Bufo spinosus and Rana temporaria , but not of Alytes obstetricans . Bayesian SourceTracker analysis further showed that the environmental contribution from biofilms to amphibian skin micro-eukaryotic assemblages was higher in Bd -positive lakes for B. spinosus and R. temporaria , but not for A. obstetricans . IMPORTANCE Research on host-associated microbiomes and infectious diseases has mostly focused on bacteria, overlooking the potential contributions of micro-eukaryotes to infection dynamics. Here, we show that environmental and skin-associated micro-eukaryotes—especially putative anti- Batrachochytrium dendrobatidis ( Bd) fungi—differ between Bd -positive and Bd -negative amphibian populations in mountain lakes. Our results suggest that micro-eukaryotes influence disease resistance and microbiome assembly, similarly to bacteria. Importantly, environmental reservoirs of micro-eukaryotes appear to contribute differently across infection contexts. These findings demonstrate the importance of adopting a broader microbiome perspective that includes micro-eukaryotes when investigating the ecological mechanisms underlying infectious disease risk.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".