title: Emerging linezolid-resistant Enterococcus faecalis and Enterococcus faecium isolated from two Austrian patients in the same intensive care unit.
abstract: Of two patients in the same intensive care unit who were treated with linezolid, one yielded linezolid-resistant Enterococcus faecalis, whereas the other yielded linezolid-resistant Enterococcus faecium. In each case, molecular typing indicated that the resistant isolates were related to linezolid-susceptible isolates from the same patient, but differed from them by the same G2576U ribosomal RNA mutation. This is the first clinical case report of emerging resistance to linezolid among Enterococcus faecalis and also the first report of resistance involving vancomycin-susceptible rather than vancomycin-resistant enterococci. The linezolid-resistant isolates showed cross-resistance to the experimental oxazolidinone AZD2563, suggesting that oxazolidinone resistance might be a class effect.
authors.affiliation: Antibiotic Resistance Monitoring and Reference Laboratory, Central Public Health Laboratory, Colindale, London NW9 5HT, UK. ajohnson@phls.org.uk
authors.forename: A P
authors.initials: AP
authors.lastname: Johnson
authors.forename: L
authors.initials: L
authors.lastname: Tysall
authors.forename: M V
authors.initials: MV
authors.lastname: Stockdale
authors.forename: N
authors.initials: N
authors.lastname: Woodford
authors.forename: M E
authors.initials: ME
authors.lastname: Kaufmann
authors.forename: M
authors.initials: M
authors.lastname: Warner
authors.forename: D M
authors.initials: DM
authors.lastname: Livermore
authors.forename: F
authors.initials: F
authors.lastname: Asboth
authors.forename: F J
authors.initials: FJ
authors.lastname: Allerberger
mesh_terms: D000081:Acetamides / Q000494:pharmacology*; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001317:Austria; D001483:Base Sequence; D003428:Cross Infection / Q000175:diagnosis / Q000382:microbiology*; D004269:DNA, Bacterial; D004352:Drug Resistance, Microbial; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000302:isolation & purification; D016984:Enterococcus faecium / Q000187:drug effects* / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000175:diagnosis*; D006801:Humans; D007362:Intensive Care Units; D000069349:Linezolid; D008297:Male; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D008969:Molecular Sequence Data; D023303:Oxazolidinones / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity
chemical_list: D000081:Acetamides; D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D023303:Oxazolidinones; D000069349:Linezolid