title: Combination of multiplex PCRs for staphylococcal cassette chromosome mec type assignment: rapid identification system for mec, ccr, and major differences in junkyard regions.
abstract: Staphylococcal cassette chromosome mec (SCCmec) typing, in combination with genotyping of the Staphylococcus aureus chromosome, has become essential for defining methicillin-resistant S. aureus (MRSA) clones in epidemiological studies. We have developed a convenient system for SCCmec type assignment. The system consists of six multiplex PCRs (M-PCRs) for identifying the ccr gene complex (ccr), the mec gene complex (mec), and specific structures in the junkyard (J) regions: M-PCR with primer set 1 (M-PCR 1) identified five types of ccr genes; M-PCR 2 identified class A to class C mec; M-PCRs 3 and 4 identified specific open reading frames in the J1 regions of type I and IV and of type II, III, and V SCCmec elements, respectively; M-PCR 5 identified the transposons Tn554 and PsiTn554 integrated into the J2 regions of type II and III SCCmec elements; and M-PCR 6 identified plasmids pT181 and pUB110 integrated into J3 regions. The system was validated with 99 MRSA strains carrying SCCmec elements of different types. The SCCmec types of 93 out of the 99 MRSA strains could be assigned. The SCCmec type assignments were identical to those made with a PCR system that uses numerous primer pairs to identify genes or gene alleles. Our system of six M-PCRs is thus a convenient and reliable method for typing SCCmec elements.
authors.affiliation: Department of Infection Control Science, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Kondo
authors.forename: Teruyo
authors.initials: T
authors.lastname: Ito
authors.forename: Xiao Xue
authors.initials: XX
authors.lastname: Ma
authors.forename: Shinya
authors.initials: S
authors.lastname: Watanabe
authors.forename: Barry N
authors.initials: BN
authors.lastname: Kreiswirth
authors.forename: Jerome
authors.initials: J
authors.lastname: Etienne
authors.forename: Keiichi
authors.initials: K
authors.lastname: Hiramatsu
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques / Q000379:methods; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial / Q000235:genetics; D004251:DNA Transposable Elements / Q000235:genetics*; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D008712:Methicillin / Q000494:pharmacology; D016106:Methicillin Resistance / Q000235:genetics; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D016133:Polymerase Chain Reaction / Q000379:methods*; D015203:Reproducibility of Results; D017422:Sequence Analysis, DNA; D013210:Staphylococcus / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D013211:Staphylococcus aureus / Q000145:classification / Q000187:drug effects / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D008712:Methicillin