Large chromosomal inversion correlated with spectinomycin resistance in<i>Lactococcus lactis</i>subsp.<i>lactis</i>bv. diacetylactis S50
Bibliographic record
Abstract
A large chromosomal inversion that confers resistance to high concentrations of the antibiotic spectinomycin in Lactococcus lactis subsp. lactis bv. diacetylactis S50 was identified by pulsed field gel electrophoresis. The same type of inversion was identified in 4 independent experiments and in 4 different derivatives of strain S50, indicating the same position and the same mechanism of recombination as a response to antibiotic selective pressure in all derivatives. An analysis of ribosomal operons in strain S50 and mutants revealed that ribosomal operons are not endpoints of the recombination. Spectinomycin-resistant mutants appeared in a population of S50 derivatives at a high frequency of 2 x 10(-7). These spectinomycin-resistant mutants were not able to compete successfully with the wild-type strain during 25 generations (48 h) of co-culture in vitro, indicating that inversion had a significant fitness cost. Results demonstrate that as a mechanism of genome plasticity, inversion can be directly involved in one-step development of the adaptation to a high concentration of spectinomycin.
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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 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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".