Virulence of<i>Francisella</i>spp. in Chicken Embryos
Bibliographic record
Abstract
We examined the utility of infecting chicken embryos as a means of evaluating the virulence of different Francisella sp. strains and mutants. Infection of 7-day-old chicken embryos with a low dose of F. novicida or F. tularensis subsp. holarctica live vaccine strain (LVS) resulted in sustained growth for 6 days. Different doses of these two organisms were used to inoculate chicken embryos to determine the time to death. These experiments showed that wild-type F. novicida was at least 10,000-fold more virulent than the LVS strain. We also examined the virulence of several attenuated mutants of F. novicida, and they were found to have a wide range of virulence in chicken embryos. Fluorescent microscopic examination of infected chicken embryo organs revealed that F. tularensis grew in scattered foci of infections, and in all cases the F. tularensis appeared to be growing intracellularly. These results demonstrate that infection of 7-day-old chicken embryos can be used to evaluate the virulence of attenuated F. tularensis strains.
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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".