vanA-containing Enterococcus faecium susceptible to vancomycin and teicoplanin because of major nucleotide deletions in Tn1546
Bibliographic record
Abstract
OBJECTIVES: During the course of routine screening for vancomycin-resistant enterococci (VRE), we found six Enterococcus faecium isolates positive for vanA by PCR, but susceptible to vancomycin and teicoplanin by phenotypic testing. The aim of this study was to characterize the genetic composition of the Tn1546 vanA gene cluster of these isolates. METHODS: The E. faecium isolates were characterized by antibiotic susceptibility, PFGE and structural analysis of the Tn1546 elements. Plasmids extracted from these isolates were used to determine the presence of the Tn1546 vanA gene cluster by PCR and the genomic organization of the deleted Tn1546 element by primer walking DNA sequencing. RESULTS: The vancomycin-susceptible vanA-positive E. faecium isolates showed three PFGE patterns, and were missing the vanR and vanS genes that are responsible for the activation of transcription of resistance genes. Primer walking sequencing revealed that these genes were completely deleted and that interruptions in the vanA cluster were in the vicinity of insertion sequence elements. CONCLUSIONS: The presence of vancomycin-susceptible vanA-positive E. faecium in clinical samples results from major deletions in the Tn1546 vanA operon. Our findings support the essential role of vanR and vanS for the expression of resistance to vancomycin in enterococci.
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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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) | 0.000 | 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".