title: Incidence and detection of multi-drug-resistant enterococci in Dublin hospitals.
abstract: In February 1994, an outbreak of vancomycin-resistant Enterococcus faecium (VREM) occurred in the oncology unit of a Dublin hospital. Between February and July 1994, VREM was isolated from 18 patients, one staff member and 14 environmental sites within the unit. The isolates also had high-level aminoglycoside and penicillin resistance. Three pulsed-field gel electrophoresis (PFGE) types were identified, two of them from multiple patients and environmental sites. Plasmid typing allowed subdivision of PFGE types. A retrospective study of enterococci isolated from blood cultures between January 1991 and January 1994 showed that, before the outbreak, fewer than 2% of isolates were vancomycin-resistant but that the incidence of high-level gentamicin resistance had increased from 17% to 60% and ampicillin resistance from 22% to 51%. Among clinically significant non-blood-culture enterococci isolated between September and December 1993, fewer than 1% were vancomycin-resistant, 13% were ampicillin-resistant and 44% highly gentamicin-resistant. None produced beta-lactamase. High-content gentamicin disks (120 micrograms) and low-content vancomycin disks (5 micrograms) allowed simple, reliable detection of resistant enterococci. MICs of vancomycin and teicoplanin determined by agar dilution and E-test agreed well, but values tended to be slightly lower by E-test.
authors.affiliation: Department of Clinical Microbiology, St James's Hospital, Dublin, Ireland.
authors.forename: A
authors.initials: A
authors.lastname: Lavery
authors.forename: A S
authors.initials: AS
authors.lastname: Rossney
authors.forename: D
authors.initials: D
authors.lastname: Morrison
authors.forename: A
authors.initials: A
authors.lastname: Power
authors.forename: C T
authors.initials: CT
authors.lastname: Keane
mesh_terms: D000668:Ampicillin Resistance; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000382:microbiology; D016000:Cluster Analysis; D003428:Cross Infection / Q000453:epidemiology* / Q000382:microbiology; D004269:DNA, Bacterial / Q000032:analysis; D004196:Disease Outbreaks; D018432:Drug Resistance, Multiple; D016521:Electrophoresis, Gel, Pulsed-Field; D016984:Enterococcus faecium / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D005243:Feces / Q000382:microbiology; D005839:Gentamicins / Q000494:pharmacology; D016908:Gram-Positive Bacterial Infections / Q000453:epidemiology* / Q000382:microbiology; D006801:Humans; D015994:Incidence; D007494:Ireland / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D011815:R Factors / Q000737:chemistry; D017334:Teicoplanin / Q000494:pharmacology; D014640:Vancomycin / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D005839:Gentamicins; D017334:Teicoplanin; D014640:Vancomycin