title: Reduced susceptibility to quinupristin/dalfopristin in Enterococcus faecium in Greece without prior exposure to the agent.
abstract: During 2005-2006, a total of 865 Enterococcus faecium isolated from patients from eight Greek hospitals were tested for susceptibility to quinupristin/dalfopristin (Q/D). Among them, 250 genetically unrelated strains (28.9%) were found to be intermediate-resistant to Q/D (minimum inhibitory concentration (MIC) 1.5-4 mg/L); all were resistant to dalfopristin (MIC=16-64 mg/L), whilst 69% were resistant to quinupristin, carrying the ermB gene. No strain was found to carry any of the known genes, such as vatE and vatD, involved in Q/D resistance, indicating that a non-transferable undetermined mechanism is responsible for the expression of low-level Q/D resistance. The high percentage of Q/D-intermediate-resistant E. faecium in Greece was not associated with prior consumption of the agent or with the veterinary use of virginiamycin.
authors.affiliation: Department of Microbiology, Medical School, University of Thessalia, Papakyriazi 22, Larissa 41222, Greece.
authors.forename: M
authors.initials: M
authors.lastname: Karanika
authors.forename: A
authors.initials: A
authors.lastname: Prati
authors.forename: M
authors.initials: M
authors.lastname: Kiritsi
authors.forename: I
authors.initials: I
authors.lastname: Spiliopoulou
authors.forename: I
authors.initials: I
authors.lastname: Neonakis
authors.forename: M
authors.initials: M
authors.lastname: Anifantaki
authors.forename: E
authors.initials: E
authors.lastname: Petinaki
mesh_terms: D000123:Acetyltransferases / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D024881:Drug Resistance, Bacterial; D016984:Enterococcus faecium / Q000187:drug effects* / Q000302:isolation & purification; D016908:Gram-Positive Bacterial Infections / Q000382:microbiology*; D006115:Greece; D006801:Humans; D008826:Microbial Sensitivity Tests; D014769:Virginiamycin / Q000494:pharmacology*
chemical_list: D001426:Bacterial Proteins; D014769:Virginiamycin; C062940:quinupristin-dalfopristin; D000123:Acetyltransferases; C084756:streptogramin A acetyltransferase, Enterococcus faecium; C477287:virginiamycin acetyltransferase D