Fig. 6.

Expression of CptBA system varies under different stressful conditions in A. baumannii ATCC 17978. Fold change in the transcription levels of cptA and cptB genes upon exposure to (A) different antibiotics, (B) oxidative stress and (C) high temperature (42 °C vs 37 °C). Significant downregulation was observed in cptBA under the effect of 10 mM H₂O₂, and in the presence of ciprofloxacin (32 µg/ml) and meropenem (32 µg/ml). Fold change was calculated using the ΔΔCt method. The data represent the means of three independent experiments. The error bars represent the standard error of the means. Asterisks (*) indicate statistically significant differences (at p < 0.05), as determined by the unpaired Student’s t-test.