Characteristics of Escherichia coli sequence type 131 isolates that produce extended-spectrum β-lactamases: global distribution of the H30-Rx sublineage
Bibliographic record
Abstract
We designed a study to describe the characteristics of sequence type 131 (ST131) lineages, including the <em>H</em>30-Rx sublineage, among a global collection of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli isolates from 9 countries collected from 2000 to 2011. A total of 240 nonrepeat isolates from Canada, the United States, Brazil, the Netherlands, France, the United Arab Emirates (UAE), India, South Africa, and New Zealand were included. Established PCR, sequencing, and typing methods were used to define ST131 lineages, <em>H</em>30 and <em>H</em>30-Rx phylogenetic groups, <em>gyrA</em> and <em>parC</em> mutations, virotypes, and plasmid-mediated quinolone resistance determinants. The majority of the isolates produced CTX-M-15 with <em>aac(6â²)-lb-cr</em>, belonged to phylogenetic group B2, and were positive for the <em>H</em>30 lineage with the <em>gyrA1AB</em> and <em>parC1aAB</em> mutations. ST131 showed 15 distinct pulsotypes; 43% of the isolates belonged to four pulsotypes, with a global distribution. Seventy-five percent of the ST131 isolates belonged to <em>H</em>30-Rx; this sublineage was present in all the countries and was associated with multidrug resistance, <em>bla</em><sub>CTX-M-15</sub>, <em>aac(6â²)-lb-cr</em>, and virotypes A and C. The <em>H</em>41 lineage was negative for the ST131 <em>pabB</em> allele-specific PCR. The multidrug-resistant <em>H</em>30-Rx sublineage poses an important public health threat due to its global distribution, association with virotype C, and high prevalence among ST131 isolates that produce CTX-M-15.
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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 | 0.001 |
| 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".