Reduced lipopolysaccharide O antigen expression, increased acid susceptibility and multicellular behaviour in an<i>Escherichia coli</i>isolate after long-term<i>in vitro</i>exposure to formic acid
Bibliographic record
Abstract
Organic acids are being used in animal husbandry due to their positive effects on overall health and growth rate in animal husbandry. However, little is known about the long-term effects of organic acids on the normal microbiota. In this work, an Escherichia coli strain isolated from a healthy pig was passed weekly for 20 months in medium with and without formic acid (FA) to investigate the effects of long-term exposure to organic acids. Passages were made using buffered medium at pH 5.25 and 6.1 with and without FA. Colonies showing reduced O antigen lipopolysaccharide production and increased susceptibility to FA were isolated after 12 months exposure to FA at pH 5.25 and after 20 months exposure to FA at pH 6.1. Adaptation to acid and bacterial growth was strongly affected by FA at pH 5.25. Also, after 2 months of serial passages, we observed colonies exhibiting multicellular behaviour, with production of fimbriae and an extracellular matrix. We conclude that long-term exposure to FA of an E. coli isolate from the normal intestinal microbiota is associated with various changes in the bacterial cell surface involving reduced O antigen expression and increased extracellular matrix production together with increased susceptibility to FA.
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 | 0.000 | 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) | 0.001 | 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".