Biofilm production in Escherichia coli K30 with group 1 capsular gene wza and wza-wzb-wzc deletions is not correlated with Erythromycin resistance phenotypes in liquid media
Bibliographic record
Abstract
The Wzy-dependent capsular polysaccharide export system consists of an outer membrane channel (Wza), inner membrane channel and tyrosine autokinase (Wzc), and regulatory phosphatase (Wzb), and is responsible for the export and assembly of extracellular polysaccharide capsules. In Escherichia coli K30, this system is critical for the formation of group 1 capsules. Previous studies have shown that E. coli K30 Δwza and Δwza-wzb-wzc have greater resistance to erythromycin, a macrolide antibiotic, on solid media compared to wild-type K30; however, the opposite phenotype was observed in liquid media. Therefore, we hypothesized that the different erythromycin resistance phenotypes in E. coli K30 wild-type, Δwza, and Δwza-wzb-wzc are due to differences in biofilm production in solid and liquid media. In this study, we investigated whether biofilm formation is correlated with the differential erythromycin resistance phenotype of wild-type E. coli K30, Δwza, and Δwza-wzb-wzc in solid and liquid media. Erythromycin disc diffusion assays on solid media, minimum inhibitory concentration assays in liquid media and crystal violet biofilm assays were performed on all three strains. We found that Δwza and Δwza-wzb-wzc were more resistant than the wild-type strain on solid media, but all three strains had similar levels of resistance in liquid media. In contrast to previous studies, we obtained consistent erythromycin MIC values in liquid media and determined that it was between 125 and 250 μg/mL, but we were unable to obtain consistent biofilm formation among our three trials. Thus, we conclude that there is no correlation between biofilm production and erythromycin resistance in E. coli K30 wild-type, Δwza, and Δwza-wzb-wzc in liquid media.
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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 | 0.000 | 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) | 0.000 | 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".