Table 2

IC90s of β-lactams against H37Rv, RPFnull, and related strains

β-LactamStrainaIC90 (μM)b
CefotaximeH37Rv (RPFWT)26
H37RvΔrpfA13–26
H37RvΔrpfB13–26
H37RvΔrpfC26
H37RvΔrpfD26
H37RvΔrpfE26–52
H37RvΔrpfAB26
H37RvΔrpfACBED::pHrpfCDE6.5–26
H37RvΔrpfACBE6.5
H37RvΔrpfACBED (RPFnull)1.6–3.3
H37RvΔrpfACDEBc0.78
CefamandoleH37Rv (RPFWT)390–780
H37RvΔrpfACBED (RPFnull)98
    With potassium clavulanate (1 μM)H37Rv (RPFWT)24
H37RvΔrpfACBED (RPFnull)1.5
CeftriaxoneH37Rv (RPFWT)3.2–6.3
H37RvΔrpfACBED (RPFnull)1.6
  • a From reference 5.

  • b Differences in IC90s are representative of at least two independent experiments containing at least four duplicates each; for cefamandole, amounts of clavulanate were varied across duplicates.

  • c RPFs were deleted from this strain in a different order than that for RPFnull.