Distribution of<i>Streptococcus mitis</i>biovar 1 phenotypes on shedding and non-shedding oral surfaces of human infants during the first year of life
Bibliographic record
Abstract
α -Hemolytic streptococci represent a numerically significant fraction of human commensal oropharyngeal bacteria and various species have preferences for particular surfaces. On the basis of the production of neuraminidase, β 1-Nacetylglucosaminidase, and β 1-N-acetylgalactosaminidase we identified four phenotypes of Streptococcus mitis biovar 1, a pioneer in the human mouth. Isolates contained in these four groups differed in their ability to produce IgA1 protease and to bind salivary α -amylase, two properties proposed as ecological determinants for viridans streptococci. The purpose of our study was to determine whether production of these glycosidases, IgA1 protease activity, and salivary a-amylase binding conferred an advantage on S. mitis biovar 1 for soft and hard tissue colonization. We studied 3330 isolates of S. mitis biovar 1 obtained from buccal mucosa, dorsum of tongue and labial surfaces of the primary central incisors of four infants on eight or nine visits from birth to 1 year of age. Isolates producing neuraminidase predominated and showed a preference for colonizing mucosal surfaces. In contrast, the production of IgA protease and/or salivary α -amylase binding did not confer an ecological advantage. While isolates producing neuraminidase were predominant, the production of this enzyme was not required for successful colonization, since neuraminidase-negative isolates were consistently recovered from the infants’ mouths, albeit in lower numbers. Clearly, physiological properties required for successful colonization of the mouth extend beyond the determinants examined in the current study. However, our data are a small first step in understanding properties that enable strains of S. mitis biovar 1 to colonize and persist in the human oral cavity. Key words: S. mitis biovar 1, infants, mouth, neuraminidase, IgA1 protease, α -amylase
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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 | 0.000 |
| 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".