Photoinactivation of bacterial and fungal planktonic/biofilm forms using the combination of a porphyrinic formulation with potassium iodide

Cátia Vieira, Maria Bartolomeu, Adriele R. Santos, Mariana Q. Mesquita, Ana T. P. C. Gomes, Maria Graça P. M. S. Neves, Maria Amparo F. Faustino*, Adelaide Almeida*

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review

Abstract

Antimicrobial photodynamic therapy (aPDT) is a promising approach against multidrug-resistant microorganisms. In this work, we accessed the photodynamic efficiency of an affordable formulation composed of five cationic porphyrins (FORM) and its combined effect with potassium iodide (KI) on a large spectrum of microorganisms. For this purpose, the aPDT assays were conducted with FORM alone and FORM + KI on planktonic and biofilm forms of Gram(+) (Staphylococcus aureus) and Gram(−) (Escherichia coli) bacteria and of the yeast Candida albicans. The results obtained indicate that FORM, at low concentrations (0.5–5.0 μM), had an efficient photodynamic action on the planktonic forms of E. coli, S. aureus, and C. albicans. Moreover, the combination of FORM with KI improved the photodynamic action of this PS, promoting microbial inactivation with lower PS concentrations and treatment time. The combination of FORM + KI was also extremely efficient in the destruction of bacterial and fungal biofilms. This outstanding effect may be due to the action of longer-lived iodine reactive species produced by the reaction of KI with the ROS generated by FORM during the aPDT treatment.
Original languageEnglish
Article number13
Number of pages7
JournalMedical Sciences Forum
Volume12
Issue number1
DOIs
Publication statusPublished - 15 Jun 2022

Keywords

  • Antimicrobial photodynamic therapy
  • Cationic porphyrins
  • Formulation
  • Potassium iodide
  • Biofilms
  • Planktonic cells

Fingerprint

Dive into the research topics of 'Photoinactivation of bacterial and fungal planktonic/biofilm forms using the combination of a porphyrinic formulation with potassium iodide'. Together they form a unique fingerprint.

Cite this