TABLE 1.

Relative fitness of the wild type and Fusr mutants in vitro and in vivod

fusA alleleEF-G mutation(s)Growth rate, in vitroaGeneration time, in vivobMIC (μg/ml)c
Wild typeWild type1.001.00100-200
fusA1-1P413L, G13C0.980.94200
fusA1-2P413Q1.020.85400
fusA1-7P413V0.980.68800
fusA1-8P413L, A66V0.980.662,400
fusA1-11P413L, F444L0.980.592,400
fusA1-14P413L, V291E0.980.36800
fusA1-15P413L, T423I0.980.33>3,200
fusA1P413L0.520.002,400
  • a The in vitro growth rate is the relative growth rate in M9 glucose minimal medium, with that of the wild type set at 1.00.

  • b The in vivo generation time is the relative generation time in BALB/c mice, with that of the wild type set at 1.00. Values are calculated from growth competition assays in a mouse intraperitoneal infection model as described previously (3) and are taken from this reference.

  • c The MIC is the minimal inhibitory concentration of fusidic acid (in micrograms/milliliter) required to inhibit bacterial growth in a microtiter well assay (21).

  • d All values are the arithmetic means of the results from at least four independent measurements.