| Abstract [eng] |
In this work we investigated the influence of multidrug resistance pumps on photobactericidal efficiency of photosensitizer safranine O on Gram-negative bacteria Escherichia coli and Salmonella enterica serovar Typhimurium. We identified bactericidal efficiency of the dye safranine O and inhibitor of RND pumps phenylalanine-arginine-β-naphthylamide (PAβN) for bacterial cells. It was found, that inhibitor PAβN strengthen safranine O phototoxic effects. This suggests that the photosensitizer safranine O is one of the MDR pumps’ substrate in E. coli and S. enterica serovar Typhimurium cells. These pumps remove the photosensitizer from the interior of cells and help to prevent bacteria from photobactericidal action. We also investigated influence of bacterias‘ physiologic state on photobactericidal efficiency of photosensitizer safranine O. Bacterial cells spread on a rich nutrient medium prior to exposure to photosensitizer, become more resistant to photobactericidal effect of safranine O, but PAβN reduce this effect. Bacterial mutants - E coli KMA with inactive AcrA protein and S. enterica serovar Typhimurium L109 with inactive TolC protein of efflux systems are more sensitive to photokilling compared to the wild type cells. |
