The remarkable effect of potassium iodide in eosin and rose bengal photodynamic action against salmonella typhimurium and staphylococcus aureus

Adriele R. Santos*, Andréia F.P. Batista, Ana T.P.C. Gomes, Maria da Graça P.M.S. Neves, Maria Amparo F. Faustino, Adelaide Almeida, Noboru Hioka, Jane M.G. Mikcha

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)

Abstract

Antimicrobial photodynamic therapy (aPDT) has been shown as a promising technique to inactivate foodborne bacteria, without inducing the development of bacterial resistance. Knowing that addition of inorganic salts, such as potassium iodide (KI), can modulate the photodynamic action of the photosensitizer (PS), we report in this study the antimicrobial effect of eosin (EOS) and rose bengal (RB) combined with KI against Salmonella enterica serovar Typhimurium and Staphylococcus aureus. Additionally, the possible development of bacterial resistance after this combined aPDT protocol was evaluated. The combination of EOS or RB, at all tested concentrations, with KI at 100 mM, was able to efficiently inactivate S. Typhimurium and S. aureus. This combined approach allows a reduction in the PS concentration up to 1000 times, even against one of the most common foodborne pathogenics, S. Typhimurium, a gram-negative bacterium which is not so prone to inactivation with xanthene dyes when used alone. The photoinactivation of S. Typhimurium and S. aureus by both xanthenes with KI did not induce the development of resistance. The low price of the xanthene dyes, the non-toxic nature of KI, and the possibility of reducing the PS concentration show that this technology has potential to be easily transposed to the food industry.
Original languageEnglish
Article number211
JournalAntibiotics
Volume8
Issue number4
DOIs
Publication statusPublished - Dec 2019
Externally publishedYes

Keywords

  • Antimicrobial resistance
  • Inorganic salt
  • Photodynamic inactivation
  • Salmonella
  • Xanthene derivatives

Fingerprint

Dive into the research topics of 'The remarkable effect of potassium iodide in eosin and rose bengal photodynamic action against salmonella typhimurium and staphylococcus aureus'. Together they form a unique fingerprint.

Cite this