title: Novel multiplex PCR assay for characterization and concomitant subtyping of staphylococcal cassette chromosome mec types I to V in methicillin-resistant Staphylococcus aureus.
abstract: Staphylococcal cassette chromosome mec (SCCmec) typing is essential for understanding the molecular epidemiology of methicillin-resistant Staphylococcus aureus (MRSA). SCCmec elements are currently classified into types I to V based on the nature of the mec and ccr gene complexes, and are further classified into subtypes according to their junkyard region DNA segments. Previously described traditional SCCmec PCR typing schemes require multiple primer sets and PCR experiments, while a previously published multiplex PCR assay is limited in its ability to detect recently discovered types and subtypes such as SCCmec type V and subtypes IVa, b, c, and d. We designed new sets of SCCmec type- and subtype-unique and specific primers and developed a novel multiplex PCR assay allowing for concomitant detection of the methicillin resistance (mecA gene) (also serving as an internal control) to facilitate detection and classification of all currently described SCCmec types and subtypes I, II, III, IVa, b, c, d, and V. Our assay demonstrated 100% sensitivity and specificity in accurately characterizing 54 MRSA strains belonging to the various known SCCmec types and subtypes, when compared with previously described typing methods. Further application of our assay in 453 randomly selected local clinical isolates confirmed its feasibility and practicality. This novel assay offers a rapid, simple, and feasible method for SCCmec typing of MRSA, and may serve as a useful tool for clinicians and epidemiologists in their efforts to prevent and control infections caused by this organism.
authors.affiliation: Centre for Antimicrobial Resistance, Calgary health Region/Calgary Laboratory services/University of Calgary, Calgary, Alberta, Canada T2L 2K8. kunyan.zhang@cls.ab.ca
authors.forename: Kunyan
authors.initials: K
authors.lastname: Zhang
authors.forename: Jo-Ann
authors.initials: JA
authors.lastname: McClure
authors.forename: Sameer
authors.initials: S
authors.lastname: Elsayed
authors.forename: Thomas
authors.initials: T
authors.lastname: Louie
authors.forename: John M
authors.initials: JM
authors.lastname: Conly
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D015373:Bacterial Typing Techniques; D002876:Chromosomes, Bacterial / Q000235:genetics*; D006801:Humans; D008712:Methicillin / Q000494:pharmacology; D016106:Methicillin Resistance / Q000235:genetics*; D008826:Microbial Sensitivity Tests; D016133:Polymerase Chain Reaction / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013203:Staphylococcal Infections / Q000382:microbiology; D013211:Staphylococcus aureus / Q000145:classification* / Q000187:drug effects / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D008712:Methicillin