title: Evaluation of a cefoxitin disk diffusion test for the detection of mecA-positive methicillin-resistant Staphylococcus saprophyticus.
abstract: In order to validate the current Clinical and Laboratory Standards Institute (CLSI) criteria for the detection of mecA-mediated resistance in Staphylococcus saprophyticus, 101 clinical isolates, including 8 mecA-positive isolates, were investigated. All the isolates were in the range of the resistant category for coagulase-negative staphylococci with the 1 microg oxacillin disk diffusion method and agar dilution method, despite 93 isolates (92%) being mecA-negative. On the other hand, the 30 microg cefoxitin disk diffusion method showed clearly distinguishable zone diameters between the mecA-positive and -negative isolates. However, four of the mecA-negative isolates that would be considered resistant were false positive, and the current interpretive criteria of the CLSI may thus require reconsideration. This study suggests that the cefoxitin disk diffusion method could be more suitable than the oxacillin disk diffusion method for detecting mecA-mediated resistance in S. saprophyticus.
authors.affiliation: Department of Microbiology, Graduate School of Comprehensive Human Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Higashide
authors.forename: Makoto
authors.initials: M
authors.lastname: Kuroda
authors.forename: Saburo
authors.initials: S
authors.lastname: Ohkawa
authors.forename: Toshiko
authors.initials: T
authors.lastname: Ohta
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000032:analysis / Q000502:physiology*; D002440:Cefoxitin / Q000494:pharmacology*; D006801:Humans; D016106:Methicillin Resistance; D008826:Microbial Sensitivity Tests / Q000379:methods*; D046915:Penicillin-Binding Proteins; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D046915:Penicillin-Binding Proteins; C487789:mecA protein, Staphylococcus aureus; D002440:Cefoxitin