Methicillin resistant Staphylococcus aureus (MRSA) with
multiple drug resistance patterns is frequently isolated from
skin and soft tissue infections that are involved in chronic
wounds. Today, difficulties in the treatment of MRSA associated
infections have led to the development of alternative
approaches such as antimicrobial photodynamic therapy. This
study aimed to investigate photoinactivation with cationic
porphyrin derivative compounds against MRSA in in-vitro
conditions. In the study, MRSA clinical isolates with different
antibiotic resistance profiles were used. The newly synthesized
cationic porphyrin derivatives (PM, PE, PPN, and PPL) were used
as photosensitizer, and 655 nm diode laser was used as light
source. Photoinactivation experiments were performed by
optimizing energy doses and photosensitizer concentrations.
In photoinactivation experiments with different energy densities
and photosensitizer concentrations, more than 99% reduction
was achieved in bacterial cell viability. No decrease
in bacterial survival was observed in control groups. It was
determined that there was an increase in photoinactivation
efficiency by increasing the energy dose. At the energy dose
of 150 J/cm2 a survival reduction of over 6.33 log10 was observed
in each photosensitizer type. While 200 μM PM concentration
was required for this photoinactivation, 12.50 μM
was sufficient for PE, PPN, and PPL. In our study, antimicrobial
photodynamic therapy performed with cationic porphyrin
derivatives was found to have potent antimicrobial efficacy
against multidrug resistant S. aureus which is frequently
isolated from wound infections.