1361. <i>Actinotignum schaalii</i> an Under-recognized Cause of Infections: A Case Series in Calgary from 2012 - 2020
Bibliographic record
Abstract
Abstract Background Actinotignum schaalii is a gram-positive rod that is a fastidious commensal of the urogenital tract. Infections with A. schaalii are underdiagnosed previously because phenotypic methods fail to identify it. Both MALDI-TOF mass spectrometry and 16S rRNA sequencing allow definitive identification of this opportunistic emerging pathogen. A. schaalii is an infrequent but important cause of UTIs in the elderly, particularly with urological abnormalities. The spectrum of invasive disease caused by A. schaalii is not well characterized; however, it has been isolated in severe infections including necrotizing skin and soft tissue infections, bacteremia, osteomyelitis, and endocarditis. We used a population-based approach to characterize and describe the clinical and microbiological features of invasive A. schaalii infections in our region. Methods All adult and pediatric cases enrolled had microbiological isolates of Actinotignum schaalii recovered from blood cultures, sterile fluids and tissue cultures from Jan 2012 to Dec 2020 by APL, a regional centralized microbiology laboratory serving the Calgary Zone in Alberta, Canada. Clinical data were retrieved and linked from administrative health databases, chart review and the laboratory information system. Standard descriptive statistics were used. Results We identified 84 unique A. schaalii infections, 35 were from bloodstream, 32 soft tissue, 7 post-operative infections. Median age and Charslon comorbidity score was higher in BSI. 54.3% of patient with BSI had a genitourinary pathology, with 51.4% caused by a complicated urinary infection, while soft and skin tissue infections caused 65.3% of non-BSI. Using EUCAST MIC cut-offs, 48% and 100% of the isolates were resistant to clindamycin and metronidazole, respectively. In contrast, all specimens were susceptible to penicillin. Hospitalization and 90-days mortality were higher in the BSI group. Conclusion A. schaalii is an anaerobic opportunistic pathogen that can cause life-threatening invasive infections, particularly in older adults with underlying genitourinary pathology. BSI were associated with higher rates of hospitalization and mortality. In contrast, patients with A. schaalii isolated from cutaneous sources were younger and had better clinical outcomes. Disclosures All Authors: No reported disclosures
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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 | 0.002 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.003 | 0.003 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.002 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.002 | 0.002 |
| Insufficient payload (model declined to judge) | 0.002 | 0.001 |
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".