Role of peroxiredoxin of the AhpC/TSA family in antioxidant defense mechanisms of Francisella tularensis
Fig 2
The ΔahpC mutant of F. tularensis LVS exhibits enhanced sensitivities towards superoxide generating compounds.
The sensitivities of the wild type F. tularensis (Ft) LVS, the ΔahpC mutant, and the transcomplemented strain (ΔahpC+pahpC) as determined by disc diffusion and spot assays against superoxide-generating compounds menadione (A and D), pyrogallol (B and E) and paraquat (C and F). For disc diffusion assays, the results are expressed as a zone of inhibition in millimeters obtained using the indicated concentrations of the compounds and are expressed as Mean ± S.D. of triplicate samples. In spot assays, the Francisella strains were exposed to serially diluted menadione, pyrogallol and paraquat for 1 and 3 hours and spotted on MH-chocolate agar plates to determine the bacterial killing. The red arrows indicate enhanced killing of the ΔahpC mutant at the indicated concentrations of the compounds. All the results shown are representative of 3 independent experiments conducted. The p values were determined by one-way ANOVA and a p-value of <0.05 is considered statistically significant. *p<0.05; ***p<0.001.