Susceptibility of sodA- and sodB-deficient Escherichia coli mutant towards antimicrobial photodynamic inactivation via the type I-mechanism of action

Conclusion The present study showed that sodA- and sodB-inactivated mutants are highly susceptible to PACT. The lack of anti- oxidant enzymes is an essential factor for the survival of bacteria. Bacterial protection in TI- and TII-based PACT can be partially supported by quenching agents such as SOD and CAT. Furthermore, no upregulation of sodA- and sodB-genes has yet been observed after photodynamic treatment under the given conditions. Therefore, this type of bacterial defense mechanism might be ineffective against PACT