title: Comparison of two commercially available selective media to screen for vancomycin-resistant enterococci.
abstract: Campylobacter medium (CAMPY, Becton Dickinson [BD] Microbiology Systems, Cockeysville, MD) and Vancomycin Screen Agar (VSA, BD) were compared for their ability to screen for vancomycin-resistant Enterococcus (VRE) from primary plates. A microdilution minimal inhibitory concentration (MIC) assay (Pasco, BD) served as the reference vancomycin MIC. In the random sample of 200 enterococcal clinical isolates tested, the distribution of isolates was as follows: Enterococcus faecium, 113 (97 VRE); Enterococcus faecalis, 71(12 VRE); Enterococcus gallinarum, 10; and Enterococcus casseliflavus, 6. Of the 75 vancomycin-susceptible strains, none grew on CAMPY and 4 grew on VSA, whereas all 109 VRE isolates grew on both screen plates. Of the 16 strains with a Van C phenotype, ie, E. gallinarum and E. casseliflavus, 2 grew on CAMPY and 14 on VSA. Of the 899 clinical specimens plated onto both agars, 45 of 67 VRE were detected with both media, 20 were detected only with CAMPY and 2 were not detected by either screen plate. CAMPY compared with VSA as a primary plating medium was more sensitive and, when used to screen for VRE isolates from primary plates, was more specific for strains displaying Van A and B phenotypes.
authors.affiliation: Department of Pathology, University of California Irvine Medical Center, 92697-4800, USA.
authors.forename: Janet
authors.initials: J
authors.lastname: Shigei
authors.forename: Grace
authors.initials: G
authors.lastname: Tan
authors.forename: Amy
authors.initials: A
authors.lastname: Shiao
authors.forename: Luis M
authors.initials: LM
authors.lastname: de la Maza
authors.forename: Ellena M
authors.initials: EM
authors.lastname: Peterson
mesh_terms: D003470:Culture Media; D016983:Enterococcus / Q000187:drug effects / Q000302:isolation & purification*; D006801:Humans; D020713:Vancomycin Resistance
chemical_list: D003470:Culture Media