TABLE 1.

β-lactam MICs

StrainamecAMIC (μg/ml)b
NafAmpCefazCefoxCTXBPRNaf + CefoxcBPR + Cefoxc
COLn+25616256256>25612561
COLnex0.5<0.250.544<0.25
CRB128256>256825612848
  • a COLnex is a mecA-negative variant of COL; CRB is a β-lactam-resistant derivative of COLnex; COLn is a tetracycline-sensitive derivative of COL.

  • b Naf, nafcillin; Amp, ampicillin; Cefaz, cefazolin; CTX, ceftriaxone; BPR, ceftobiprole; Cefox, cefoxitin.

  • c The cefoxitin concentration was 1 μg/ml.