Prevalence, risk factors, and molecular analysis of vancomycin-resistant Enterococci colonization in a referral neonatal intensive care unit: a prospective study in northern Iran

Abstract

Vancomycin-resistant enterococcus (VRE) is an emerging drug-resistant organism responsible for increasing nosocomial infections. Few data are available on the epidemiology of VRE colonization or infection in neonates, and is of recent interest. This study analyzes the prevalence of neonatal VRE colonization in a neonatal intensive care unit (NICU), and describes risk factors and molecular phenotypes associated with VRE colonization. We performed a prospective epidemiological study on neonates admitted to an NICU. We compared neonates with VRE isolates detected in rectal swab cultures to those without. Association of VRE colonization with risk factors was tested by using univariate and multivariate methods. During a period of 18 months, amongst 180 neonates enrolled in the study, 76 (42.2%) were colonized by VRE. VRE isolates were resistant to amikacin in 68%, gentamicin in 26%, and ampicillin in 17.1% of cases. Molecular analysis showed the vanA gene in all isolates. Two VRE-positive patients developed infection during the observation time. No deaths occurred during this period. Prematurity (P=0.023), low birth weight (P=0.019), history of admission in other hospitals (P=0.00), and antibiotic therapy for more than seven days (P=0.01) were identified as risk factors for VRE colonization. Newborn susceptibility to early colonization with VRE in NICUs is increased in preterm and low birth weight newborns. All VRE colonization in the NICU was related to the acquisition of the vanA gene. Adherence to infection control policies and antimicrobial stewardship strategies are of the highest importance.