Determination of vancomycin resistant enterococci (VRE) carriage, molecular epidemiology and the related risk factors in children with ALL in Ali-asghar children hospital and Mahak hospital, Tehran, Iran

The infection due to vancomycin resistant Enterococcus in immune deficient patient is a significant factor for increase in morbidity and mortality. The aim of this study was to determine VRE carriage rate and it’s molecular epidemiology and to identify risk factors for acquisition of VRE in children with ALL in Iran. In a cross-sectional study, stool samples of children with ALL in Aliasghar and Mahak hospital were randomly analyzed for detection of VRE. All isolates were sent to a reference centre for further investigation. Enterococci strains were identified by conventional methods and vancomycin resistance was studied by disk diffusion method and E-test. Van gene characterization was performed by a multiplex polymerase chain reaction (PCR). Of 130 children with ALL, 33 patients were colonized with vancomycin-resistant strains (VRE) and 62 patients were colonized with vancomycin-sensitive strains (VSE). Twenty- six isolates (78.8%) of VRE showed VanA phenotype and seven isolates (21.2%) exhibited VanB phenotype. In the univariate analysis, history of ICU admission (P=0.03) was significantly associated with Enterococcus colonization and had a trend with VRE colonization. Age (P=0,007) was significantly associated with VRE phenotype. There was no significant relationship between gender, duration of disease, number of admission, another disease, history of severe neutropenia among one month ago and history of antibiotic use in three month ago and VRE colonization. Our study demonstrated that VRE prevalence is high in children with ALL in Iran and indicated a prompt intervention strategy in the control of VRE particulary in PICU.