Antimicrobial activity of cationic water-soluble porphyrin against multidrug-resistant bacteria in biofilms and canine skin samples.

Multidrug-resistant (MDR) microorganisms pose a threat to animal health, particularly in integumentary diseases, which can be caused by multiple organisms and often manifest as biofilms, hindering treatment effectiveness. We evaluated the antimicrobial activity of antimicrobial photodynamic therapy (aPDT) using a water-soluble tetra-cationic porphyrin (4-HTMeP) against MDR bacteria cultured in biofilm and in mono and polyculture grown on canine skin samples. We utilized 4-HTMeP porphyrin against MDR Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus pseudintermedius.