Table 1.

Bactericidal killing by penicillin

StrainDecrease in cell count (log10CFU/ml) with penicillin concn ofa:
2 μg/ml5 μg/ml10 μg/ml
OG1RF0.75 ± 0.113.96 ± 0.163.62 ± 0.18
TX51270.18 ± 0.08b3.36 ± 0.13c3.03 ± 0.08d
  • a Initial inocula were about 107 CFU/ml. Data are expressed as mean (log10CFU per ml at 24 h of growth without penicillin −log10 CFU per milliliter at 24 h of growth with penicillin) ± standard deviation (n = 6).

  • b P < 0.001 versus OG1RF by Student’s two-tailed t test.

  • c P = 0.03 versus OG1RF by Student’s two-tailed t test.

  • d P = 0.04 versus OG1RF by Student’s two-tailed t test.