LAUSR

Dielectric barrier discharge (DBD) plasma treatments are more effective against Gram negative bacteria than Gram-positive bacteria. Effects of DBD plasma were compared on Salmonella Typhimurium and Staphylococcus aureus cells. Physical cell membrane integrity and function, deoxyribonucleic acid (DNA) oxidation, and intracellular reactive oxygen species (ROS) were measured. The difference in physical damage caused by plasma on Gram-negative and Gram positive bacteria implied a difference in cellular damage pattern, which may be due to differences in cell structure and composition. Antimicrobial particles in plasma react directly with the outer membranes of Gram-negative bacteria and eventually kill them; however, ROS produced from plasma first penetrated the cell wall and membrane of Gram-positive bacteria before reacting with internal cellular components and killing the bacteria.