title: Daptomycin non-susceptible Enterococcus faecium in leukemia patients: Role of prior daptomycin exposure.
abstract: We sought to determine the association between previous daptomycin exposure and daptomycin non-susceptible Enterococcus faecium (DNSEf) bloodstream infections (BSI) in adult leukemia patients.
  
  
  
  We retrospectively identified adult (≥18 years old) leukemia patients with Enterococcus spp. bacteremia at The University of Texas MD Anderson Cancer Center (MDACC) from 6/1/2013 to 7/22/2015. Antimicrobial susceptibility and previous antibiotic exposure within the 90 days prior to bacteremia were collected. Classification and Regression Tree (CART) analysis was used to identify the most significant breakpoint between daptomycin exposure and DNSEf.
  
  
  
  Any amount of daptomycin received within the 90 days preceding BSI was significantly associated with isolation of DNSEf compared to daptomycin susceptible E. faecium (DSEf) (88% vs. 44%, respectively, p < 0.01). CART analysis identified receiving ≥13 days of daptomycin in the preceding 90 days as most significantly correlated with DNSEf (60% vs. 11%, relative risk [RR] 5.31, 95% Confidence interval [CI] 2.36-11.96, p < 0.01).
  
  
  
  Prior daptomycin exposure for ≥13 days within 90 days preceding BSI was significantly associated with isolation of DNSEf BSI in adult leukemia patients at our institution. Antimicrobial stewardship initiatives aimed at minimizing daptomycin exposure in high-risk patients may be of significant benefit in limiting the emergence of DNSEf.
authors.affiliation: Division of Pharmacy, Unit 0090, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA. Electronic address: ajdipippo@mdanderson.org.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: DiPippo
authors.affiliation: Division of Pharmacy, Unit 0090, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA. Electronic address: fptverdek@mdanderson.org.
authors.forename: Frank P
authors.initials: FP
authors.lastname: Tverdek
authors.affiliation: Department of Laboratory Medicine, Unit 0084, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA. Electronic address: jtarrand@mdanderson.org.
authors.forename: Jeffrey J
authors.initials: JJ
authors.lastname: Tarrand
authors.affiliation: Center for Antimicrobial Resistance and Microbial Genomics, University of Texas McGovern School of Medicine, 6431 Fannin St, Houston, TX 77225, USA; Clinica Alemana, Universidad del Desarrollo, Av Vitacura 5951, Santiago, Región Metropolitana, Chile. Electronic address: jose.m.munita@uth.tmc.edu.
authors.forename: Jose M
authors.initials: JM
authors.lastname: Munita
authors.affiliation: Center for Antimicrobial Resistance and Microbial Genomics, University of Texas McGovern School of Medicine, 6431 Fannin St, Houston, TX 77225, USA. Electronic address: truc.t.tran@uth.tmc.edu.
authors.forename: Truc T
authors.initials: TT
authors.lastname: Tran
authors.affiliation: Center for Antimicrobial Resistance and Microbial Genomics, University of Texas McGovern School of Medicine, 6431 Fannin St, Houston, TX 77225, USA; Department of Infectious Diseases, Infection Control, and Employee Health, Unit 1460, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA. Electronic address: cesar.arias@uth.tmc.edu.
authors.forename: Cesar A
authors.initials: CA
authors.lastname: Arias
authors.affiliation: Department of Infectious Diseases, Infection Control, and Employee Health, Unit 1460, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA; Department of Genomic Medicine, Unit 1460, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA. Electronic address: sshelburne@mdanderson.org.
authors.forename: Samuel A
authors.initials: SA
authors.lastname: Shelburne
authors.affiliation: Division of Pharmacy, Unit 0090, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030, USA; Center for Antimicrobial Resistance and Microbial Genomics, University of Texas McGovern School of Medicine, 6431 Fannin St, Houston, TX 77225, USA. Electronic address: slaitken@mdanderson.org.
authors.forename: Samuel L
authors.initials: SL
authors.lastname: Aitken
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology* / Q000627:therapeutic use; D016470:Bacteremia / Q000188:drug therapy / Q000382:microbiology*; D015331:Cohort Studies; D017576:Daptomycin / Q000494:pharmacology* / Q000627:therapeutic use; D024881:Drug Resistance, Bacterial; D016984:Enterococcus faecium / Q000187:drug effects* / Q000302:isolation & purification; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy / Q000382:microbiology*; D006801:Humans; D007938:Leukemia / Q000150:complications / Q000382:microbiology*; D000069349:Linezolid / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D012372:ROC Curve; D012189:Retrospective Studies; D012307:Risk Factors; D014640:Vancomycin / Q000008:administration & dosage / Q000494:pharmacology / Q000627:therapeutic use
chemical_list: D000900:Anti-Bacterial Agents; D014640:Vancomycin; D000069349:Linezolid; D017576:Daptomycin
keywords: Antibiotic exposure; Linezolid; Resistance; Risk factor; Vancomycin