Photoantimicrobials - a PACT against resistance and infection

The upsurge in multidrug-resistant bacteria, e.g., methicillin-resistant Staphylococcus aureus (MRSA), in the rsealthcare milieu represents a serious clinical problem with associated high morbidity and mortality. Since resistant strains are selected by the overuse of single-site/mode-of-action therapeutics, different approaches to bacterial eradication are required. Similarly, traditional disinfection protocols for donated blood and blood products are inadequate in the face of the AIDS pandemic and other emerging pathogens. Photosensitizing drugs operate via the generation of reactive oxygen species upon illumination in situ. The lack of microbial resistance mechanisms, e.g., against singlet oxygen, ensures a wide range of topical/local applications across bacteria, viruses, yeasts and protozoa. This underlines the potential of photoantimicrobial chemotherapy (PACT) in infection control, whether in antisepsis of in the inhibition of transfusion/transmission of disease.