TABLE 2.

MICs of several β-lactams for strain Rd recombinants carrying defined mutations in PBP 3 and for strain Rd for comparison

StrainAmino acid mutations by site-directed mutagenesisMIC (μg/ml)b
377Ma385S389L517R526NCTXCECCDRCPDCDNCPNAMPIPMMEM
Rd0.00810.250.0310.0080.0080.1250.1250.031
Recombinant
    1K0.01680.50.1250.0160.0310.2510.031
    2TK0.0311610.250.0160.0630.510.031
    3ITK0.031810.1250.0160.0630.510.031
    4TFK0.0633220.250.0310.1250.520.031
    5ITFK0.0631620.250.0310.1250.510.031
    6TH0.0161610.1250.0080.0310.250.1250.031
    7ITH0.01680.50.1250.0080.0310.250.1250.031
    8TFH0.0311620.250.0160.0630.50.1250.031
    9ITFH0.031810.250.0160.0630.50.1250.031
    10TFHK0.0311620.250.0160.0630.50.50.031
    11ITFHK0.031820.250.0160.0630.50.1250.031
    12ITF0.031210.250.0160.0630.250.1250.031
  • a The amino acid on PBP 3 in strain Rd.

  • b CTX, cefotaxime; CEC, cefaclor; CDR, cefdinir; CPD, cefpodoxime; CDN, cefditoren; AMP, ampicillin; IPM, imipenem; MEM, meropenem.