Molecular epidemiology of Enterobacter cloacae in a neonatal department: a 2-year surveillance study

A surveillance program was implemented to investigate the molecular epidemiology of Enterobacter cloacae in neonatal units. This program ran for 2 years and involved screening for E. cloacae intestinal colonization of all infants at admission and weekly thereafter. In addition, mothers whose children were admitted to neonatal units were also screened. Pulsed-field gel electrophoresis analysis was used to establish genetic relationships between strains and to identify mother-to-child transmission. During the survey period, 166 (22.6%) of the 735 included children had E. cloacae intestinal colonization, and 29 (3.9%) patients gave clinical samples positive for E. cloacae. Genotyping revealed 90 different pulsotypes in the 199 clinical and screening isolates from neonates, including three major epidemic clones. Mother-to-child transmission of E. cloacae was directly responsible for 8.8% of intestinal colonization of the neonates. This surveillance program reveals a major contribution of patient-to-patient transmission and the rarity of mother-to-child transmission in the spread of E. cloacae in neonates. This highlights the importance of good compliance with infection control procedures by health-care workers.