Sequential emergence and quantitative dynamics of key bacterial species preceding digital dermatitis lesion onset in dairy cattle
Bibliographic record
Abstract
Digital dermatitis (DD) is a skin infection of cattle’s feet with multiple bacteria suspected to be involved, yet its precise etiopathogenesis remains unclear. This longitudinal study explored the temporal changes of seven DD-associated bacteria in feet developing lesions or remaining healthy, while simultaneously investigating their persistence in potential reservoirs as sources of infection. Weekly swabs were collected from feet skin and saliva of 53 Holstein cows without DD lesions sequentially enrolled at calving in a commercial dairy herd. At the end of the study, samples from all cases and a subset of matched controls were analyzed (1:2 ratio) at five-time points (weeks −3, −2, −1, 0 - when early signs of DD were observed - and +1) and subjected to qPCR targeting Treponema phagedenis, T. medium, T. pedis, Porphyromonas levii, Bacteroides pyogenes, Fusobacterium necrophorum , and F. mortiferum . Linear mixed-effect models assessed the bacterial number changes within cows (cases) and between cows (cases vs controls). Throughout the study, 8 cows developed signs of DD. P. levii, F. necrophorum, and B. pyogenes numbers increased two weeks before the first visible lesion. T. phagedenis and T. pedis numbers increased one week before, suggesting a sequential colonization and potential synergism in triggering DD. Only P. levii and F. necrophorum were persistently present in saliva and skin, while Treponema spp. persisted solely in lesions. Our results inform specific bacterial dynamics associated with DD pathogenesis and might advise future attempts to effectively treat and control DD. • Temporal changes in bacterial load around the onset of digital dermatitis. • Successive bacterial colonization and synergism may play a role in DD pathogenesis. • P. levii , B. pyogenes , and F. necrophorum numbers increased two weeks prior to lesion onset. • T. phagedenis and T. pedi s numbers increased a week before lesion development
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 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 teacher head, 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".