Reproduction of porcine ear necrosis (ear-tip necrosis) following intradermal inoculation of pigs with Fusobacterium necrophorum
Bibliographic record
Abstract
Porcine ear necrosis (PEN) (also referred to as ear-tip necrosis, ETN) is a syndrome of global presence and unclear aetiology. Initially reported in the 1950s, many different infectious and non-infectious causes have been suggested as the causative(s) agent(s), but none has been confirmed in controlled studies. Here, we investigated the aetiology of PEN using pure culture of bacteria associated with lesions in controlled animal trials. A commercial farm with no history of ear-tip necrosis was identified and used as the source for 5-week-old pigs. Two independent trials were initially executed with identical designs. Piglets (=12/trial) were intradermally inoculated with either pure cultures of Staphylococcus hyicus or Fusobacterium necrophorum (left ear, n = 10) or sterile media (right ear, n = 10). Two pigs in each trial were not inoculated, serving as sentinels. A third trial used F. necrophorum as the inoculum, 3 pigs as sentinels and 9 as inoculated. All animals were clinically monitored daily following challenge, and an ear score was used to follow disease progression. All ears inoculated with S. hyicus remained lesion free. Four out of ten and 7/9 pigs challenged with F. necrophorum developed lesions undistinguishable from PEN, including necrosis and loss of portions of the ear pinna (P < 0.001). F. necrophorum was isolated from 4/10 and 7/9 pigs that developed necrotic lesions. Histopathology after resolution of necrosis revealed granulomatous tissue. Evidence presented here suggests that F. necrophorum causes PEN-like lesions, as seen in commercial barns. It is therefore suggested as the etiological agent of this syndrome.
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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 | 0.002 | 0.001 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.001 |
| 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".