Epidemiology of enteric bacteria in neonatal units--influence of procedures and patient variables.

Among 953 infants in 22 neonatal care units studied, 23% (median value, range 0-78) were found to be faecally colonized with one of 21 distinct nosocomial strains of Escherichia coli, Klebsiella or Enterobacter spp. Lower birth weight was associated with such colonization, particularly with nosocomial phenotypes of E. coli. Caesarean section followed by prolonged incubator care, and hospital stay, were additional factors associated with colonization by such strains of E. coli. Antibiotic therapy of the infant and type of feeding were not found to be associated with acquisition of nosocomial strains of enteric bacteria among neonates.