title: A polyclonal outbreak of bloodstream infections by Enterococcus faecium in patients with hematologic malignancies.
abstract: BACKGROUND
  Enterococcus faecium causes bloodstream infection (BSI) in patients with hematologic malignancies (HMs). We studied the clinical features and outcomes of patients with HM with vancomycin-sensitive E faecium (VSE) and vancomycin-resistant E faecium (VRE) BSI and determined the genetic relatedness of isolates and circumstances associated with the upsurge of E faecium BSI.
  
  
  METHODS
  Case-control study of patients with HM and E faecium-positive blood culture from January 2008-December 2012; cases were patients with VRE and controls were VSE isolates. The strains were tested for Van genes by polymerase chain reaction amplification and we performed pulsed-field gel electrophoresis to determine genetic relatedness.
  
  
  RESULTS
  Fifty-eight episodes of E faecium BSI occurred: 35 sensitive and 23 resistant to vancomycin. Mortality was 46% and 57%, attributable 17% and 40%, respectively. Early stage HM was associated with VSE (P = .044), whereas an episode of BSI within the 3 months before the event (P = .039), prophylactic antibiotics (P = .013), and vancomycin therapy during the previous 3 months (P = .001) was associated with VRE. The VanA gene was identified in 97% of isolates studied. E faecium isolates were not clonal.
  
  
  CONCLUSIONS
  E faecium BSI was associated with high mortality. This outbreak of VRE was not clonal; it was associated with antibiotic-use pressure and highly myelosuppressive chemotherapy.
authors.affiliation: Departmento de Enfermedades Infecciosas, Secretaría de Salud, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Pamela
authors.initials: P
authors.lastname: Alatorre-Fernández
authors.affiliation: Programa de Inmunología Molecular Microbiana, Departamento de Microbiología y Parasitología, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Claudia
authors.initials: C
authors.lastname: Mayoral-Terán
authors.affiliation: Departamento de Enfermedades Infecciosas, Laboratorio de Microbiología, Secretaría de Salud, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Consuelo
authors.initials: C
authors.lastname: Velázquez-Acosta
authors.affiliation: Departamento de Farmacología Hospitalaria, Secretaría de Salud, Instituto Nacional de Cancerología, Mexico City, Mexico.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Franco-Rodríguez
authors.affiliation: Programa de Inmunología Molecular Microbiana, Departamento de Microbiología y Parasitología, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Karen
authors.initials: K
authors.lastname: Flores-Moreno
authors.affiliation: Programa de Genómica Evolutiva, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos, Mexico.
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Cevallos
authors.affiliation: Programa de Inmunología Molecular Microbiana, Departamento de Microbiología y Parasitología, División de Investigación, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: López-Vidal
authors.affiliation: Departmento de Enfermedades Infecciosas, Secretaría de Salud, Instituto Nacional de Cancerología, Mexico City, Mexico. Electronic address: pvolkowf@gmail.com.
authors.forename: Patricia
authors.initials: P
authors.lastname: Volkow-Fernández
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D004269:DNA, Bacterial / Q000235:genetics; D004196:Disease Outbreaks; D016521:Electrophoresis, Gel, Pulsed-Field; D016984:Enterococcus faecium / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D005260:Female; D014644:Genetic Variation; D005838:Genotype; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D019337:Hematologic Neoplasms / Q000150:complications*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017720:Molecular Epidemiology; D058889:Molecular Typing; D016133:Polymerase Chain Reaction; D012189:Retrospective Studies; D018805:Sepsis / Q000453:epidemiology* / Q000382:microbiology; D016019:Survival Analysis; D065507:Vancomycin-Resistant Enterococci / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial
keywords: Molecular epidemiology; Mucosal barrier injury; Vancomycin-resistant Enterococcus faecium