title: Strategies to potentiate antimicrobial photoinactivation by overcoming resistant phenotypes.
abstract: Conventional antimicrobial strategies have become increasingly ineffective due to the emergence of multidrug resistance among pathogenic microorganisms. The need to overcome these deficiencies has triggered the exploration of alternative treatments and unconventional approaches towards controlling microbial infections. Photodynamic therapy (PDT) was originally established as an anticancer modality and is currently used in the treatment of age-related macular degeneration. The concept of photodynamic inactivation requires cell exposure to light energy, typically wavelengths in the visible region that causes the excitation of photosensitizer molecules either exogenous or endogenous, which results in the production of reactive oxygen species (ROS). ROS produce cell inactivation and death through modification of intracellular components. The versatile characteristics of PDT prompted its investigation as an anti-infective discovery platform. Advances in understanding of microbial physiology have shed light on a series of pathways, and phenotypes that serve as putative targets for antimicrobial drug discovery. Investigations of these phenotypic elements in concert with PDT have been reported focused on multidrug efflux systems, biofilms, virulence and pathogenesis determinants. In many instances the results are promising but only preliminary and require further investigation. This review discusses the different antimicrobial PDT strategies and highlights the need for highly informative and comprehensive discovery approaches.
authors.affiliation: Department of Chemistry, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina.
authors.forename: Domingo Mariano Adolfo
authors.initials: DM
authors.lastname: Vera
authors.forename: Mark H
authors.initials: MH
authors.lastname: Haynes
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Ball
authors.forename: Tianhong
authors.initials: T
authors.lastname: Dai
authors.forename: Christos
authors.initials: C
authors.lastname: Astrakas
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kelso
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hamblin
authors.forename: George P
authors.initials: GP
authors.lastname: Tegos
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects; D018441:Biofilms; D005658:Fungi / Q000187:drug effects; D006801:Humans; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D000890:Anti-Infective Agents; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species