Novel approach to control Salmonella enterica by modern biophotonic technology: photosensitization.

摘要

Salmonellosis is one of the most common foodborne diseases in the world. The aim of this study was to evaluate the antibacterial efficiency of 5-aminolevulinic acid (ALA) based photosensitization against Salmonella enterica. S. enterica was incubated with ALA (7.5 mmol l-1) for 1-4 h and afterwards illuminated with visible light. The light source used for illumination of S. enterica emitted light lambda = 400 nm with energy density 20 mW cm-2. The illumination time varied from 0 to 20 min and subsequently, the total energy dose reached 0-24 J cm-2. The data obtained indicate that S. enterica is able to produce endogenous photosensitizer PpIX when incubated with ALA. Remarkable inactivation of microorganisms can be achieved (6 log) after photosensitization. It is obvious that photosensitization-based inactivation of S. enterica depends on illumination as well as incubation with ALA time. Results suggest that ALA-based photosensitization could be an effective tool against multi-drug resistant Gram-negative Salmonella Typhimurium.