Contributions of O Island 48 to Adherence of Enterohemorrhagic <i>Escherichia coli</i> O157:H7 to Epithelial Cells In Vitro and in Ligated Pig Ileal Loops
Bibliographic record
Abstract
O island 48 (OI-48) of Escherichia coli consists of three functional gene clusters that encode urease, tellurite resistance (Te(r)), and putative adhesins Iha and AIDA-1. The functions of these clusters in enterohemorrhagic E. coli (EHEC) O157:H7 infection are unknown. Deletion mutants for these three regions were constructed and evaluated for their ability to adhere to epithelial cells in vitro and in ligated pig ileal loops. Deletion of the Te(r) gene cluster reduced the ability of the organism to adhere to and form large clusters on IPEC-J2 and HEp-2 cells. Complementation of the mutation by introducing the wild-type ter genes restored adherence and large-cluster formation. Tests in ligated pig ileal loops showed a decrease in colonization by the Te(r)-negative mutant, but the difference was not significant compared to colonization by the wild type (26.4% +/- 21.2% versus 40.1% +/- 19.1%; P = 0.168). The OI-48 aidA gene deletion had no effect on adherence in vitro or in vivo. Deletion of the iha and ureC genes had no effect on adherence in vitro but significantly reduced the colonization of EHEC O157:H7 in the ligated pig intestine. These data suggest that Te(r), Iha, and urease may contribute to EHEC O157:H7 pathogenesis by promoting adherence of the pathogen to the host intestinal epithelium.
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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".