TABLE 3

Effect of A. baumannii PBP3 mutations on acylation rate constant of Bocillin, sulbactam, aztreonam, imipenem, and meropenem

Parameter and PBP3 mutationSubstratea
BocillinSulbactamAztreonamImipenemMeropenem
kinact/Ki (M−1 · s−1) ± SD
    Wild type18,000 ± 3,00014 ± 2700 ± 100470 ± 505,000 ± 1,000
    S390T250 ± 300.1 ± 0.1900 ± 300b540 ± 40b16,000 ± 6,000b
    S395F740 ± 700.6 ± 0.1110 ± 209 ± 11,500 ± 300
    T511S4,200 ± 4001.5 ± 0.1450 ± 80220 ± 203,400 ± 400
% of wild type ± SD
    S390T1.4 ± 0.20.4 ± 0.4140 ± 50110 ± 20300 ± 100
    S395F4.1 ± 0.74.5 ± 0.816 ± 41.9 ± 0.329 ± 8
    T511S24 ± 410 ± 270 ± 2047 ± 760 ± 20
  • a For Bocillin, n = 18 for wild type and n = 13 for others. For sulbactam, aztreonam, imipenem, and meropenem, n = 4 for wild type and n = 3 for others.

  • b Not a statistically significant difference from wild type at P ≤ 0.05 by two-sided Student's t test.