Biological characteristics and whole-genome analysis of the <i>Enterococcus faecalis</i> phage PEf771
Bibliographic record
Abstract
Enterococcus faecalis is a common pathogen causing refractory periapical periodontitis and secondary intraradicular infections. In this study, E. faecalis YN771 isolated from a re-treated root canal at a stomatology department was used as the host bacterium and was co-cultured with wastewater from the same department and patient samples to isolate a phage that lyses E. faecalis. We studied the biological and genomic characteristics of this phage. Transmission electron microscopy showed that this phage’s head is icosahedral in structure, with a head diameter of around 98.4 nm, and a contractile tail of around 228.5 nm in length and a diameter of 17.3 nm. The phage was identified as a member of the Myoviridae family and named PEf771. It is sensitive to proteinase K but resistant to chloroform and Triton X-100. Its lytic cycle is 45 min, burst size is 78, optimal multiplicity of infection is 0.1, lysis spectrum is narrow, and host strain specificity is strong. Its optimal growth temperature is 37 °C, most suitable pH is 6.0, and is sensitive to ultraviolet radiation. Whole-genome sequencing of PEf771 indicated it has a genome size of 151 052 bp, with a GC content of 36.97%, and encodes 197 proteins plus 26 tRNAs. PEf771 is most closely related to E. faecalis phage EFDG1. Phage PEf771 has strong host specificity and lytic ability, so it is important to further characterize this phage and its interaction with E. faecalis.
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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 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 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) | 0.001 | 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".