259. A Retrospective Cross-Sectional Comparison of the Neonatal Gut Microbiota After Antimicrobial Exposure: Implications for Stewardship
Bibliographic record
Abstract
The development of the infant gut microbiota influences the maturation of the host immune system and has been implicated in both short- and long-term health outcomes. In a healthy infant, the initial stages of gut microbiota development are characterized by the progressive acquisition and proliferation of anaerobes. In the neonatal intensive care unit (NICU), infants are often exposed to antibiotics which disturb the normal development of the gut microbiota. In this retrospective cross-sectional study, we aimed to the evaluate the effects of three different antibiotic regimens on the gut microbiota of infants in the NICU, focusing on the effect on anaerobe colonization. From November 1, 2014 to April 30, 2015, stool swabs were collected from NICU patients at The Hospital for Sick Children. Infants were included in the study if they received any dose or duration of the following antibiotics: ampicillin and tobramycin (AT), ampicillin and cefotaxime (AC), or ampicillin, tobramycin, and metronidazole (ATM). DNA was extracted from stool swabs and subject to Illumina sequencing of the V4 hypervariable region of the 16S rRNA gene. Infants were stratified by gestational age (term or preterm). The first samples taken within 1 week after antibiotic exposure were analyzed for diversity measures, taxonomic composition, and anaerobe relative abundance. A total of 64 NICU infants were included in the study, 46 (71.9%) received AT, 7 (10.9%) received AC, and 11 (17.2%) received ATM. Term infants received either AT (19/46; 41.3%) or AC (7/7; 100%), whereas preterm infants received either AT (27/46; 58.7%) or ATM (11/11; 100%). Shannon diversity was not statistically significant between term infants receiving AT and AC or preterm infants receiving AT and ATM. However, the relative abundance of anaerobes was significantly decreased after exposure to ATM in comparison to preterm infants receiving AT (P < 0.005) Within 1 week after ATM therapy, the relative abundance of gut anaerobes in preterm infants were significantly decreased in comparison to preterm infants receiving a course of AT. Therefore, limiting the use of ATM in preterm infants may protect the developing gut microbiota. All authors: No reported disclosures.
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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 | 0.003 | 0.007 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".