Escherichia coli Colonization in Neonates: Prevalence, Perinatal Transmission, Antimicrobial Susceptibility, and Risk Factors

Escherichia coli is one of the leading causes of early-onset neonatal sepsis in many industrialized countries. However, there is a lack of studies on Escherichia coli colonization in women and neonates. The study aimed at determining the prevalence Escherichia coli among pregnant women and newborns, perinatal transmission, antimicrobial susceptibility, and risk factors for neonatal colonization.
Material and Methods. In this prospective, cross-sectional study, 827 infants born to 808 mothers were enrolled. The study was carried out from October 1, 2006, to June 30, 2007. Women were screened for E. coli carriage at 35–37 weeks of gestation or on admission for premature rupture of membranes and delivery; neonates, within 15 minutes of their lives. Risk factors for colonization were collected by a questionnaire and were recorded during labor.
Results. Maternal E. coli colonization rate was 19.9%; neonatal, 14.4%; and transmission rate, 21.4%. Less than one-fourth (22.7%) of neonatal E. coli strains were resistant to ampicillin. Logistic regression analysis revealed that anal sexual intercourse (OR, 3.91; 95% CI, 1.87–8.19), one sexual partner (OR, 2.01; 95% CI, 1.30–3.11), maternal vaginal Escherichia coli colonization (OR, 1.81; 95% CI, 1.12–2.93), maternal body mass index of ≤27 (OR, 1.77; 95% CI, 1.15–2.73), and maternal education lower than university level (OR, 1.70; 95% CI, 1.06–2.74) were associated with neonatal Escherichia coli colonization.
Conclusions. The prevalence of maternal Escherichia coli colonization was higher in this study than other studies (19.9%). Neonatal Escherichia coli colonization was 14.4%. The resistance of Escherichia coli isolates to ampicillin was not high (22.7%). Improvement of maternal education and modification of mothers’ sexual habits need to be undertaken to prevent neonatal Escherichia coli colonization.