Sekundarni povzetek: |
Introduction: Bacterial antimicrobial resistance poses a growing threat to human health in developed and underdeveloped regions worldwide. The spread of bacterial infections is controlled by many antimicrobial agents, but this approach often has a negative impact on our health. Due to the growth of antibiotic resistance in bacteria, our thesis will focus on the potential of plasma-based biofilm control of MRSA. Plasma produces reactive oxygen and nitrogen species which, even at low concentrations, exhibit remarkable antimicrobial properties. Aim: The aim of our research was to investigate the conditions under which plasma can effectively eliminate S. aureus and MRSA biofilms. Methods: Various methods, including colony counting, fluorescence measurements following resazurin addition, and optical density measurements were employed to separately analyze the two bacterial strains. The efficacy of 60, 120, and 180 s of plasma exposure on biofilms of different maturity (24, 48, and 72 h) was analyzed. Results: The efficacy of plasma against S. aureus and MRSA biofilms increased proportionally with increasing exposure time, as confirmed by viability, metabolism, oxidative stress, and microscopy observations. Notably, plasma had no overall effect on the increase or decrease of S. aureus and MRSA biofilm biomass. The emergence of resistance of both bacterial strains to plasma or to cefoxitin 30 was not observed in 10 bacterial generations. Discussion and conclusion: With prolonged exposure of S. aureus and MRSA biofilms to plasma, the viability and metabolic activity of both bacterial strains were reduced. Furthermore, as exposure time to plasma increased, oxidative stress in both S. aureus and MRSA was also heightened, further indicating the impact of plasma on these biofilms. Plasma treatment resulted in the removal of biofilm biomass only in the case of 72 h biofilms. Encouragingly, our investigation spanning 10 bacterial generations of plasma-exposed bacteria did not lead to any notable emergence of resistance to plasma or cefoxitin 30. In addition to its high bactericidal efficacy, plasma has the advantage of low toxicity, since, unlike chemical surface disinfection, it has no adverse impact on the environment. |