title: Culture-based detection of methicillin-resistant Staphylococcus aureus by a network of European laboratories: an external quality assessment study.
abstract: Twenty-three hospital laboratories from Europe and Israel participated in an external quality assessment (EQA) of the culture-based detection of methicillin-resistant Staphylococcus aureus (MRSA). Participants also reported the MRSA prevalence in clinical cultures and patient screening specimens, as well as the MRSA screening practices employed at their hospitals. An EQA panel of 18 samples consisting of two MRSA harbouring SCCmec IV and I, and one strain each of methicillin-resistant coagulase-negative S. epidermidis, methicillin-sensitive S. aureus and Escherichia coli as pure strains or in mixtures at 10(7)-1 cfu absolute loads was analysed by the 23 participants. Seventeen (74%) participants identified 17 or more samples correctly. Of these, 15 (88%) utilised a chromogenic medium alone (ChromID, bioMérieux; BBL CHROMagar, BD Diagnostics; MRSA Select, Bio-Rad Laboratories) or combined with a conventional medium and up to three confirmatory tests. Proportions of MRSA among S. aureus isolated from clinical cultures varied widely, even among hospitals within countries, ranging from 11-20% to 61-70%. MRSA carriage rates were less variable (0-20%) between countries. Almost all participants (n=22, 96%) screened patients for MRSA carriage during 2009-2010, of which 15 (68%) screened intensive care unit (ICU) patients alone or combined with other targeted high-risk groups, and 10 (45%) combined nasal screening with another body site.
authors.affiliation: Department of Medical Microbiology, Vaccine & Infectious Disease Institute, Universiteit Antwerpen, Antwerp, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Gazin
authors.forename: A
authors.initials: A
authors.lastname: Lee
authors.forename: L
authors.initials: L
authors.lastname: Derde
authors.forename: M
authors.initials: M
authors.lastname: Kazma
authors.forename: C
authors.initials: C
authors.lastname: Lammens
authors.forename: M
authors.initials: M
authors.lastname: Ieven
authors.forename: M
authors.initials: M
authors.lastname: Bonten
authors.forename: Y
authors.initials: Y
authors.lastname: Carmeli
authors.forename: S
authors.initials: S
authors.lastname: Harbarth
authors.forename: C
authors.initials: C
authors.lastname: Brun-Buisson
authors.forename: H
authors.initials: H
authors.lastname: Goossens
authors.forename: S
authors.initials: S
authors.lastname: Malhotra-Kumar
mesh_terms: D002353:Carrier State / Q000175:diagnosis / Q000382:microbiology; D002863:Chromogenic Compounds; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000187:drug effects / Q000302:isolation & purification; D005060:Europe; D006801:Humans; D007391:International Cooperation; D007557:Israel; D059021:Laboratory Proficiency Testing; D055624:Methicillin-Resistant Staphylococcus aureus / Q000254:growth & development / Q000302:isolation & purification*; D008826:Microbial Sensitivity Tests / Q000379:methods / Q000592:standards; D011785:Quality Assurance, Health Care; D013203:Staphylococcal Infections / Q000175:diagnosis* / Q000382:microbiology*; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000302:isolation & purification
chemical_list: D002863:Chromogenic Compounds; D003470:Culture Media