TABLE 6.

Survival of the deletion mutants ΔphoB, ΔphoR, and ΔphoBR with antibiotic exposure

Time of exposure to ApNo. of bacteria (CFU/ml)
W3110ΔphoBΔphoRΔphoBRΔphoUΔhipA
Log phaseStationary phaseLog phaseStationary phaseLog phaseStationary phaseLog phaseStationary phaseLog phaseStationary phaseLog phaseStationary phase
Start CFU3.7 × 1088 × 1091 × 1086 × 1091 × 1087 × 1091 × 1085 × 1091 × 1081 × 1092 × 1087 × 109
5 h9 × 1036 × 1096 × 1034 × 1091 × 1034 × 1097 × 1033 × 1091 × 1022 × 1081 × 1046 × 109
24 h1 × 1022 × 1091 × 1021.8 × 1091 × 1021.5 × 1092 × 1031.7 × 10907 × 1061 × 1031.8 × 109
72 h02 × 10801 × 10801 × 10802 × 1080001 × 108
  • The susceptibilities of log phase and stationary phase cultures of the deletion mutants ΔphoB, ΔphoR, ΔphoBR, ΔphoU, and ΔhipA and the wild type to ampicillin (Ap) (100 μg/ml) were determined. CFU values were determined at different times of exposure.