Subclinical colitis associated with moderately hemolytic Brachyspira strains
Bibliographic record
Abstract
Objective: Microbiological and virulence characterization of 2 moderately hemolytic Brachyspira strains. Materials and methods: Clinical isolates were obtained from diarrheic (3603-F2) and healthy (G79) pigs. Phenotypic characterization included assessment of hemolytic activity on blood agar and biochemical profiling. Genotyping was performed by sequencing the nicotinamide adenine dinucleotide oxidase (nox) gene, whole genome sequencing, and comparison to relevant Brachyspira. Pig inoculation included 4 treatment groups in 2 challenge experiments: negative control (sterile broth media; n = 12), positive control (Brachyspira hampsonii genomovar 2 strain 30446; n = 18), and 3603-F2 (n = 12) or G79 (n = 12). Fecal scoring and rectal swabbing for culture were performed daily. Animals were euthanized following onset of mucohemorrhagic diarrhea or between 21 and 28 days post inoculation (dpi). Gross and microscopic pathology were assessed. Terminal colon samples were used to characterize post-infection mucosal ion secretion. Results: Both strains were moderately hemolytic. Whole genome and nox sequencing identified 3603-F2 as Brachyspira murdochii and G79 as a novel strain. Both challenge trials revealed intestinal colonization, but no mucohemorrhagic diarrhea. Sporadic watery diarrhea was induced by 3603-F2 associated with a pattern of microscopic lesions similar to pigs with swine dysentery (positive controls). No diarrhea was observed in G79 inoculated pigs, but microscopic lesions were more severe than in controls. Both strains induced greater colonic anion secretory potential than negative controls 21 dpi. Implications: Allegedly avirulent Brachyspira species most closely related to B murdochii can be associated with subclinical colitis and may be a concern for grow-finish pigs.
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 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 | 0.001 | 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".