TABLE 1.

Bacterial strains and plasmids used in this study

Strain or plasmidRelevant characteristicsaReference
Strains
    N315Pre-MRSA strain carrying a functional mecI encoding mecA gene repressor, hetero-Metr, Nagasaki, Japan 10
    N315PPenicillinase plasmid-free strain derived from N315 10
    ΔIP mecI null mutant derived from N315P (mecI::tetL), hetero-Metr Tetr 15
    H14(or IPM8-14)Mutant derived from ΔIP by selection with 8 mg/liter of IPM, VraS (S329→L) homo-Metr Tetr 12
    ΔIP-KVR vraSR null mutant from ΔIP (vraSR::cat), Mets Tetr Chlr 12
    H14-KVR vraSR null mutant from H14 (vraSR::cat), Mets Tetr Chlr 12
    ΔIP-rifRMutant derived from ΔIP by selection with 1 mg/liter of RIF, RpoB (H481→Y) hetero-Metr Tetr RifrThis study
    ΔIP::vraSH14ΔIP in which vraS is replaced by vraSH14 (S329→L), homo-Metr TetrThis study
    ΔIP-rifR:: vraSH14ΔIP-rifR in which vraS is replaced by vraSH14, homo-Metr Tetr RifrThis study
    Mu3hVISA clinical strain, Tokyo, Japan 9
    Mu50VISA clinical strain, Tokyo, Japan 9
    NJVISA clinical strain, New Jersey 23
Plasmids
    pKOR1 S. aureus allele replacement vector 2
    pKO- vraSH14pKOR1 harboring 1.0-kb PCR product of vraSH14This study
  • a Abbreviations: Mets, methicillin susceptible; Metr, methicillin resistant; Tetr, tetracycline resistant; Chlr, chloramphenicol resistant; Ampr, ampicillin resistant; Rifr, RIF resistant. Strains obtained by antibiotic selection are denoted “mutant.”