Molecular Characterization of <i>Escherichia coli</i> Isolated from Chickens with Colibacillosis in Senegal
Bibliographic record
Abstract
Avian pathogenic Escherichia coli (APEC), a subset of extraintestinal pathogenic E. coli (ExPEC), are the etiologic agent of avian colibacillosis, one of the main causes of economic losses in the poultry industry. The aim of this study was to characterize E. coli isolated from diseased chickens in Senegal to elucidate their virulence potential and antimicrobial resistance (AMR). A total of 58 isolates, each from a separate farm, were characterized for AMR, virulence, and AMR genes, phylogroup, serogroup, biofilm formation, and pulsed-field gel electrophoresis, and for two isolates, whole-genome sequencing (WGS). Fifty isolates (86.2%) were multidrug resistant. Many AMR genes were detected, including variants of blaCTX-M encoding resistance to third-generation cephalosporins (five isolates [8.6%]). Most fluoroquinolone-nonsusceptible isolates (21/26) were carriers of mutations in gyrA (Ser83Leu, Asp87Asn, and/or Asp87Tyr) and/or parC (Ser80Ile) genes. Forty-nine (84.5%) isolates exhibited at least one of the virulence markers of APEC, among which 23 (39.7%) were defined as potential virulent APEC. In addition, 10 isolates, of which 9 were defined as APEC, carried virulence profiles corresponding to ExPEC. Seven isolates, of which six were classified as ExPEC, belonged to phylo-serogroup F-O25, and following WGS of two of these isolates, were found to belong to the serotype O25:H1 and to the sequence type ST624. Some isolates classified as ExPEC, including F-O25, were found to strongly produce biofilm, suggesting their capability to persist for long time in the environment. F-O25-isolates, although found in different widely separated farms, formed a single cluster that included clones, suggesting that these isolates may have originated from a common source. Taken together, these results suggest that some E. coli involved in chicken colibacillosis in Senegal may pose a human health risk.
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 | 0.000 | 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".