Early Life Antibiotic Exposure and Intestinal Colonization by Enterobacteriaceae upon Admission to a Neonatal...

Area of Science:

• Neonatal Medicine
• Infectious Diseases
• Antimicrobial Resistance

Background:

• Intestinal colonization by Enterobacteriaceae, including multidrug-resistant strains like ESBL-E and E-CPE, is a critical early indicator of infection risk in neonates.
• Neonates transferred from lower-complexity hospitals to referral units are particularly vulnerable to acquiring these resistant organisms.
• Understanding factors associated with colonization is crucial for developing effective prevention strategies.

Purpose of the Study:

• To identify factors associated with intestinal Enterobacteriaceae colonization in neonates admitted to a level IV neonatal referral unit in Colombia.
• To specifically investigate the impact of prior antibiotic exposure, including WHO AWaRe classification, on colonization risk.
• To analyze factors linked to colonization by extended-spectrum β-lactamase-producing (ESBL-E) and carbapenemase-producing (E-CPE) Enterobacteriaceae.

Main Methods:

• Retrospective case-control study involving 435 referred neonates screened via rectal swabs upon admission.
• Cases were neonates colonized with Enterobacteriaceae; controls were non-colonized.
• Multivariable logistic regression analyzed associations between colonization and prior antibiotic use (overall, number of agents, AWaRe classification), hospitalization duration, central catheter use, and total parenteral nutrition.

Main Results:

• Overall, 20.0% of referred neonates (87/435) were colonized, with *Klebsiella pneumoniae* and *Escherichia coli* being predominant.
• Prior antibiotic use (aOR 3.01), exposure to two agents (aOR 4.13), and use of AWaRe Access antibiotics (aOR 22.2) were strongly associated with colonization.
• AWaRe Access, Watch, and Reserve antibiotics were independently linked to ESBL-E and E-CPE colonization.

Conclusions:

• Prior antibiotic exposure, particularly WHO AWaRe-classified agents, is the most significant factor associated with intestinal Enterobacteriaceae colonization in transferred neonates.
• Strengthening antimicrobial stewardship programs in referral facilities is essential to mitigate the spread of multidrug-resistant organisms.
• Implementing risk-based screening protocols upon admission can help reduce colonization rates and subsequent infections.