Journal of Antimicrobial Agents

Antimicrobial Photodynamic Therapy for Rapid Eradication of S. Pyogenes

Abstract

J Cross, C Romo, R Andersen and N Loebel

Antimicrobial photodynamic therapy (aPDT) employs the combination of a photosensitive agent and activating light source to destroy microbes across the prokaryotic spectrum. Disinfection is mediated by high levels of oxidative stress exerted on microbial membranes, resulting in rapid kill without genomic exposure and consequent upregulation of resistance. Specificity results from the electrostatic interaction between cationic photosensitizers and generally anionic microbial membranes, an effect largely absent in zwitterionic human cells. S. pyogenes, a member of Group A streptococci, is a member of skin microbiota strongly associated with invasive skin and soft tissue infections, including necrotizing fasciitis. This study aimed to determine susceptibility of the microorganism in both planktonic and biofilm culture to aPDT, as a preparatory step to deployment in human clinical studies.