Evolution and Characterization of Penicillin-Resistant Streptococcus pneumoniae in Canadian Hospitals 2007-2010
Bibliographic record
Abstract
Streptococcus pneumoniae continues to cause considerable morbidity and mortality as a respiratory tract pathogen. Evolution and adaptation of S. pneumoniae occurs in response to antimicrobial use as well as vaccination of children and adults. The evolution of penicillin-resistant and multi-drug resistant (MDR) S. pneumoniae is of considerable concern to scientists and clinicians. In this study, penicillin-resistant isolates of S. pneumoniae were collected from the CANWARD national surveillance study over the years of 2007-2010 inclusive, and were studied to understand their demographic characterization, antimicrobial resistance patterns, serotype distribution, genetic and phenotypic relatedness, and virulence factors. This study determined penicillin-resistant S. pneumoniae from Canadian hospitals to be genetically related and frequently possess a MDR phenotype. These highly pathogenic pneumococci originated from all over Canada, and were isolated from patients from a wide age range in a variety of hospital settings. The emerging serotype 19A represented the most important source of penicillin and MDR strains. Clusters of penicillin-resistant S. pneumoniae isolates were genetically related to each other and to internationally recognized clones, including Taiwan19F-14, Spain9V-3, Spain23F-1, and England14-9. The pilus-encoding genetic islet virulence factors, PI-1 and PI-2 were associated with serotypes 19A, 19F, 9V, 14, and 35B, with PI-2 associated only with 19A and 19F isolates. In conclusion, penicillin-resistant S. pneumoniae accounted for 3.4% of all S. pneumoniae from Canadian hospitals between 2007-2010 and were isolated from patients of a wide age range, from all hospital ward types and all regions across Canada. These virulent S. pneumoniae were represented predominantly by the emerging serotype 19A, commonly exhibited a MDR phenotype, were genetically related and frequently possessed the virulence factors, P1 and P2.
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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 | 0.001 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.004 | 0.006 |
| Science and technology studies | 0.003 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| 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".