Ampicillin Treatment Increases Placental Interleukin-1 Beta Concentration and Polymorphonuclear Infiltration in Group B <b><i>Streptococcus</i></b>-Induced Chorioamnionitis: A Preclinical Study
Bibliographic record
Abstract
<b><i>Background:</i></b> Antibiotic therapy during preterm labor with intact membranes has been associated with an increased risk of neonatal death. <b><i>Objectives:</i></b> Using an established rat model of group B <i>Streptococcus</i> (GBS)-induced chorioamnionitis, we hypothesized that ampicillin treatment increases placental inflammation, as shown in other bacterial infections. <b><i>Methods:</i></b> At gestational day 19, 19 Lewis dams were intraperitoneally (i.p.) inoculated by 10<sup>8</sup> CFU of β-hemolytic serotype Ia GBS (strain #16955 susceptible to ampicillin). Dams were treated i.p. with either 200 mg/kg of ampicillin (<i>n</i> = 9) or 0.9% saline (<i>n</i> = 10) at 48 and 60 h post-GBS inoculation. Cesarean sections were performed 72 h post-GBS inoculation. <b><i>Results:</i></b> Ampicillin treatment was associated with an increased number of polymorphonuclear cells (PMN) infiltrating the decidua (mean 1,536 vs. 532 PMN/mm<sup>2</sup>; <i>p</i> &#x3c; 0.001) and a higher placental concentration of IL-1β (mean 26.4 vs. 7.9 pg/mg; <i>p</i> &#x3c; 0.01) compared to saline-treated dams. These effects were observed in dams without GBS bacteremia. Conversely, ampicillin treatment was associated with a decreased placental concentration of proinflammatory cytokines in dams with GBS bacteremia. <b><i>Conclusions:</i></b> Ampicillin increases placental inflammation in a rat model of GBS-induced chorioamnionitis without bacteremia. This proinflammatory effect of ampicillin could be due to bacterial lysis. Our findings do not query the intrapartum antibiotic prophylaxis against GBS disease. They pave the way for future preclinical studies combining anti-inflammatory treatments and antibiotic therapy for GBS-induced chorioamnionitis.
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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) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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".