Research Progress on perinatal E. coli infection.

Against the backdrop of widespread implementation of intrapartum prophylaxis for group B streptococcus (GBS), E. coli has emerged as a major pathogen of early-onset neonatal sepsis (EOS) and neonatal meningitis. Vaginal colonization of pregnant women with highly virulent E. coli is not uncommon and has been associated with adverse obstetric outcomes, including preterm birth, chorioamnionitis, and neonatal infection. Available evidence suggests that the maternal colonization rate is approximately 20-30%, and vertical transmission during delivery occurs frequently. Colonizing strains often harbor virulence determinants associated with extraintestinal pathogenic E. coli (ExPEC), with virulence profiles resembling those of uropathogenic E. coli and neonatal meningitis-associated strains. Although most exposed neonates may remain asymptomatically colonized, once invasive infection occurs, the disease can rapidly progress to sepsis or meningitis, resulting in substantial mortality and long-term neurodevelopmental sequelae. In recent years, the spread of multidrug-resistant strains, particularly extended-spectrum β-lactamase (ESBL)-producing isolates, has further complicated perinatal prevention and empirical treatment. This review summarizes current advances in perinatal E. coli infection, with a focus on maternal colonization and vertical transmission, pathogenic mechanisms, clinical manifestations, antimicrobial resistance trends, and emerging preventive strategies.