Vagino-rectal colonization and maternal-neonatal transmission of Enterobacteriaceae producing extended-spectrum β-lactamases or carbapenemases: a cross-sectional study.

This study sought to determine the prevalence and risk factors for colonization with extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) and carbapenemase-producing Enterobacteriaceae (CPE) in 815 mothers and 800 newborns using a cross-sectional design; 59 women and 13 neonates were colonized by ESBL-E (prevalence (95% confidence interval): 6.7% (5.2-8.7) and 1.6 (0.7-2.5), respectively). No CPE were found. The most frequent ESBL-E were CTX-M-14 and SHV-12. Vertical transmission occurred in 14% of colonized mothers. The risk factors for colonization were, in mothers: complications in previous pregnancies, more than one urinary tract infection, non-Caucasian ethnicity, and frequently having the main meal outside home; in newborns: colonized mother and vaginal delivery.