title: Failure of daptomycin monotherapy for endocarditis caused by an Enterococcus faecium strain with vancomycin-resistant and vancomycin-susceptible subpopulations and evidence of in vivo loss of the vanA gene cluster.
abstract: A patient with native valve endocarditis caused by a vancomycin "heteroresistant" strain of Enterococcus faecium experienced failure of daptomycin monotherapy without evidence of daptomycin resistance. The infecting organism exhibited in vivo emergence of a vancomycin-susceptible subpopulation lacking vanA. Treatment with a combination of high-dose daptomycin, gentamicin, and high-dose ampicillin cleared the infection.
authors.affiliation: Center for the Study of Emerging and Reemerging Pathogens, Division of Infectious Diseases, The University of Texas Medical School, Houston, TX 77030, USA.
authors.forename: Cesar A
authors.initials: CA
authors.lastname: Arias
authors.forename: Harrys A
authors.initials: HA
authors.lastname: Torres
authors.forename: Kavindra V
authors.initials: KV
authors.lastname: Singh
authors.forename: Diana
authors.initials: D
authors.lastname: Panesso
authors.forename: Judson
authors.initials: J
authors.lastname: Moore
authors.forename: Audrey
authors.initials: A
authors.lastname: Wanger
authors.forename: Barbara E
authors.initials: BE
authors.lastname: Murray
mesh_terms: D000667:Ampicillin / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001426:Bacterial Proteins / Q000235:genetics; D019729:Carbon-Oxygen Ligases / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D017576:Daptomycin / Q000627:therapeutic use*; D004359:Drug Therapy, Combination; D004697:Endocarditis, Bacterial / Q000188:drug therapy* / Q000382:microbiology*; D016984:Enterococcus faecium / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D005839:Gentamicins / Q000627:therapeutic use; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy* / Q000382:microbiology*; D006801:Humans; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D005810:Multigene Family; D017211:Treatment Failure; D020713:Vancomycin Resistance / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D005839:Gentamicins; C071437:VanA ligase, Bacteria; D000667:Ampicillin; D019729:Carbon-Oxygen Ligases; D017576:Daptomycin