Postgenomic Analysis of Four Novel Antigens of Group A <i>Streptococcus</i> : Growth Phase-Dependent Gene Transcription and Human Serologic Response
Bibliographic record
Abstract
Analysis of three group A Streptococcus genomes (serotypes M1, M3, and M18) recently identified four previously undescribed genes that encode extracellular proteins. Each of these genes encode proteins with an LPXTG amino acid motif that covalently links many virulence factors produced by gram-positive bacteria to the cell surface. Western immunoblot analysis of serum samples obtained from 80 patients with invasive infections, noninvasive soft tissue infections, pharyngitis, and rheumatic fever indicated that these four proteins are expressed in vivo. However, the level of gene transcript and the time of maximal gene transcription varied in representative serotype M1, M3, and M18 strains. Surface expression of two proteins was confirmed by flow cytometry. Studies using a mouse infection model suggest that antibodies specific for one of the proteins (Spy0843) may contribute to a protective host immune response against a serotype M1 infection. These results are additional evidence that postgenomic strategies provide new ways to identify and investigate novel bacterial proteins that may participate in host-pathogen interactions or serve as targets for therapeutics research.
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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 | 0.000 | 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) | 0.002 | 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".