In Vitro Study of Photodynamic Therapy for Treatment of Bacteremia in Whole Blood

Antibiotic resistance has been compromised hospitalized patients with serious infections. The main cases of bacteremia can be caused by antibiotic resistant pathogens. Photodynamic therapy (PDT) has been shown as an alternative for inactivation of microorganisms in blood. In this therapy photochemical mechanisms occur that may prevent the development of bacteria. This study aims optimization of PDT parameters for blood decontamination. Concentration of photosensitizer (PS), light dose (LD) and incubation time (IT) were studied for hemolysis and cell toxic effects. It was observed that PDT can be used for microbial inactivation in total blood reducing 0.85 log10 CFU/mL of S. aureus at 15 J/cm2 and 50 μg/mL of Photogem®.