Figure 4.

Induction of the stringent response or inhibition of respiration protects rapidly growing cultures from hypo-osmotic shock via a mechanism that requires de novo protein synthesis. Survival of exponential V. cholerae E7946 cultures in the presence of 1 mg ml⁻¹ of SHX (a) or Cm 10 μg ml⁻¹ (b) before challenge by osmotic shock or gentamicin. Alternatively, cultures were treated with Oxyrase or sodium azide (NaN₃) before osmotic shock challenge (c). Effect on the order of addition between chloramphenicol and NaN₃ evaluated in fresh water challenge (d). Graphs represent the average of at least three independent assays. Error bars show standard error. Significance was calculated using Student’s two-tailed t-test (**<0.01, ***<0.001, ****<0.0001).