title: Selection of strains for quality assessment of the disk induction method for detection of inducible clindamycin resistance in Staphylococci: a CLSI collaborative study.
abstract: A nine-laboratory collaborative study was conducted to select positive and negative quality assessment control strains for the detection of inducible clindamycin resistance in staphylococci. Four strains of Staphylococcus aureus were tested as unknowns on 10 different days in each laboratory using the recently recommended CLSI (formerly NCCLS) disk diffusion method and the inoculum purity control method. Strains contained either macrolide-lincosamide-streptogramin B (MLSB) resistance genes encoded by erm(A) or erm(C) or a macrolide resistance efflux pump encoded by msr(A). Based upon the results of this study, strain UT 32 (now designated ATCC strain BAA-977) containing erm(A) is recommended as the positive control organism for inducible clindamycin resistance. Strain UT 25 (now designated ATCC BAA-976), which harbors the efflux pump encoded by msr(A), is recommended as the negative control organism.
authors.affiliation: Microbiology Service, Department of Laboratory Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland 20892, USA.
authors.forename: Adrian M
authors.initials: AM
authors.lastname: Zelazny
authors.forename: Mary Jane
authors.initials: MJ
authors.lastname: Ferraro
authors.forename: Anita
authors.initials: A
authors.lastname: Glennen
authors.forename: Janet F
authors.initials: JF
authors.lastname: Hindler
authors.forename: Linda M
authors.initials: LM
authors.lastname: Mann
authors.forename: Susan
authors.initials: S
authors.lastname: Munro
authors.forename: Patrick R
authors.initials: PR
authors.lastname: Murray
authors.forename: L Barth
authors.initials: LB
authors.lastname: Reller
authors.forename: Fred C
authors.initials: FC
authors.lastname: Tenover
authors.forename: James H
authors.initials: JH
authors.lastname: Jorgensen
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002981:Clindamycin / Q000494:pharmacology*; D003299:Cooperative Behavior; D024901:Drug Resistance, Multiple, Bacterial; D004917:Erythromycin / Q000494:pharmacology; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D007753:Laboratories; D008826:Microbial Sensitivity Tests / Q000379:methods; D016133:Polymerase Chain Reaction; D011786:Quality Control; D013210:Staphylococcus / Q000145:classification* / Q000187:drug effects* / Q000235:genetics; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D002981:Clindamycin; D004917:Erythromycin