Lack of Association between Clinical Outcome of Clostridium difficile Infections, Strain Type, and Virulence-Associated Phenotypes
Bibliographic record
Abstract
Clostridium difficile strain NAP1/027 (North American pulsed-field gel electrophoresis [PFGE] type 1 and PCR ribotype 027 [R027]) has been associated with recent outbreaks in North America and Europe. It has been associated with more severe disease symptoms, higher mortality rates, and greater risk of relapse. This strain is thought to produce more toxins and sporulate to higher levels. However, recent studies suggest that this may not always be the case. The objective of our study was to assess, in a nonoutbreak situation, whether specific strains, such as NAP1/027, were associated with more severe disease symptoms, higher toxin production, and/or greater sporulation in vitro. We isolated and characterized C. difficile strains from 21 patients with mild to moderate, severe, or complicated symptoms of C. difficile infection (CDI). The isolates were characterized by different molecular typing methods, including PCR ribotyping, tandem repeat sequence typing (TRST), and sequencing of the tcdC gene. Fourteen isolates were of PCR ribotype 027 with deletions in tcdC, but no association with severity or clinical outcome was found. We show by immunodot blot detection of toxins with monoclonal antibodies that all R027 isolates produced more TcdA and TcdB than other strains. On the other hand, they consistently produced fewer spores than non-R027 isolates. Taken together, our data suggest that NAP1/027 isolates are not always associated with more severe disease, even though they may produce larger amounts of toxins. Our study also suggests that current assertions regarding the NAP1/027 may not apply to all isolates and that other factors may come into play.
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 | 0.005 | 0.014 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| 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 | 0.001 | 0.001 |
| 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".