Atypical Actinobacillus pleuropneumoniae serotype 12 strains with a higher virulence potential
Bibliographic record
Abstract
Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia, a disease of major economic impact. Serotype 12 is generally considered to be of low virulence and is typically associated with subclinical infections. However, we describe four atypical serotype 12 field strains recovered from severe clinical outbreaks in Chile. These strains exhibited an unusual toxin gene profile (apxIICA, apxIIICA, apxIBD, apxIIIBD), suggesting the ability to produce both ApxII and ApxIII toxins. Comparative genomic analyses revealed that these atypical strains carry the capsule genes of serotype 12 but the LPS biosynthesis genes of serotype 15, indicating a hybrid genomic structure. Phylogenetic analysis confirmed that they cluster separately from classical serotype 12 strains and are closely related to other atypical strains from Japan, USA, and Canada. Experimental infection in pigs demonstrated significantly increased virulence of the atypical Chilean strain compared to the reference strain of serotype 12, with higher clinical scores, severe lung lesions, and atypical serological responses against serotypes 3/6/8/15/17. These findings challenge the traditional view of serotype 12 as low-virulence and highlight the need for improved diagnostic approaches that incorporate both capsule and LPS profiling. The existence of these atypical strains has important implications for disease surveillance, diagnostics, and vaccine development in swine health management.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| 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) | 0.001 | 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".