Molecular Epidemiology of <i>Neisseria gonorrheae</i> Isolates with Plasmid-Mediated Tetracycline Resistance in Canada: Temporal and Geographical Trends (1986-1997)
Bibliographic record
Abstract
Plasmid-mediated resistance to tetracycline in Neisseria gonorrhoeae (TRNG) isolates is caused by the acquisition of a 25.2-MDa conjugative, tetM-containing plasmid (TetM plasmid). The presence of the TetM plasmid is the leading cause of gonococcal resistance to tetracycline in most countries. Between 1986 and 1997, 6,306 TRNG isolates were isolated in different Canadian provincial laboratories and subsequently submitted to the national laboratory for further strain characterization. Because nonculture-based identification of N. gonorrhoeae was more widely used after 1995, this snapshot of the molecular epidemiology of TRNG in Canada, which is only possible if bacteria are cultured, represents a comprehensive data baseline that may no longer be achievable. Temporal trends indicate that TRNG isolations peaked in 1994 (18.9% of isolates tested). Antimicrobial susceptibilities (MIC) to tetracycline and penicillin were determined for 4,064 TRNG isolated between 1986 and 1994. The MICs of TRNG isolates ranged from 16 microg/ml to 32 microg/ml of tetracycline, although one isolate had an MIC of 8 microg/ml and the MICs of four isolates were 2 microg/ml. Penicillinase-producing TRNG (i.e., PP/TRNG) comprised 34.1% of all TRNG (n = 1,386) and 52 TRNG isolates exhibited chromosomal resistance to penicillin. Most of the PP/TRNG (94.1%) carried Africa type (3.2 MDa) beta-lactamase-producing plasmids; only 76 (5.5%) PP/TRNG carried Asia type (4.4 MDa) penicillinase-producing plasmids and three isolates carried Toronto type (3.05 MDa) plasmids. TRNG isolates were also retrospectively typed by auxotype (A), serovar (S), and plasmid (P) content analysis. Eleven auxotype/serovar (A/S) groups comprised the majority (93%) of 4,064 typed TRNG isolates with A/S classes NR/IB-2, NR/IB-3, and NR/IB-1 accounting for 75.1% of the strains characterized. Classification of 670 TRNG for tetM type demonstrated that the Dutch (n = 531) type TetM plasmids predominated over the American (n = 139) type TetM plasmids.
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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) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.003 | 0.005 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 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 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".