Effectiveness of methylene blue antimicrobial photodynamic therapy using KI as enhancer to control Staphylococcus aureus growth


Serrano Guardiola, Anna


In this final degree project, antimicrobial photodynamic therapy has been studied as an alternative method to treat potentially pathogenic species such as Staphylococcus aureus. Antimicrobial photodynamic therapy (aPDT) consists of the application of a non-toxic dye used as a photosensitizer (PS), which together with the application of low intensity of light and oxygen produce reactive oxygen species that are responsible for the destruction of pathogenic microorganisms. . The use of antimicrobial photodynamic therapy includes several advantages, such as that it has a broad spectrum of action and is a rapid process that causes minimal damage to the host tissue. Therefore, there is less chance of promoting the appearance of mutagenicity and developing resistance. On the other hand, new research studies have shown a new approach to enhance the effect of aPDT by combining the photosensitizer and an inorganic enhancer salt. In this work, the photosensitizer of choice to carry out the experiments has been methylene blue (MB), and the inorganic salt of interest has been potassium iodide (KI). In conclusion, we can say that the studies described in this work have shown that antimicrobial photodynamic therapy is an effective methodology for the elimination of S. aureus due to the enhanced effect of combining low concentrations of MB with KI. It is a fast and safe therapy that could be applied to combat microorganisms that have serious problems in growing in resistance structures, growing on surfaces, such as biofilms.



Gulías Borau, Òscar 
Agut Bonsfills, Montserrat  


IQS SE - Undergraduate Program in Pharmacy