title: Colonization Rate and Risk Factors of Vancomycin-Resistant Enterococci among Patients Received Hematopoietic Stem Cell Transplantation in Shiraz, Southern Iran.
abstract: BACKGROUND
  Infections caused by antimicrobial-resistant bacteria are associated with increased mortality and health care costs. Enterococci have been recognized as a clinically important pathogen in hospitalized patients. Vancomycin-resistant enterococci (VRE) infections cause significant morbidity and mortality among patients undergoing transplantation.
  
  
  OBJECTIVE
  To identify epidemiology of VRE colonization and related risk factors among patients with hematological malignancies after hematopoietic stem cell transplantation (HSCT).
  
  
  METHODS
  This cross-sectional study was performed on 42 patients who underwent bone-marrow transplantation between July 2013 and March 2014. A stool sample was taken from each patient 3-5 days after transplantation and cultured on appropriate media. Suspected colonies of enterococci were detected to species level by their culture characteristics, biochemical reactions and molecular features. VRE were confirmed via phenotypic and genotypic methods.
  
  
  RESULTS
  VRE were detected in 14 (33%) of studied samples. 10 (71%) of the detected VRE isolates were identified as high level vancomycin-resistantE. faeciumwith minimum inhibitory concentration (MIC) of ≥256 μg/mL of vancomycin; 3 isolates wereE. galinarumand 1 wasE. casseliflavuswith an MIC of 8-16 μg/mL. VanA was dominant phenotype and all VRE isolates with high-level of vancomycin resistance hadvanAgene. VRE isolation was mostly observed in patients with acute lymphoblastic leukemia (ALL) than other diseases. Moreover, antibiotic prophylaxis and hospitalization were independent risk factors for acquisition of VRE after transplantation.
  
  
  CONCLUSIONS
  We found high level of vancomycin-resistance inE. faeciumisolates obtained from HSCT patients.The vancomycin-resistant isolates ofE.faeciumhadvanAand/or simultaneouslyvanBgenes.
authors.affiliation: Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Kaveh
authors.affiliation: Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: A
authors.initials: A
authors.lastname: Bazargani
authors.affiliation: Hematology Research Center, Department of Hematology-Oncology and Stem Cell Transplantation, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Ramzi
authors.affiliation: Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: H
authors.initials: H
authors.lastname: Sedigh Ebrahim-Saraie
authors.affiliation: Department of Bacteriology and Virology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: H
authors.initials: H
authors.lastname: Heidari
keywords: Colonization; Enterococcus; Risk factors; Stem cell transplant; Vancomycin