Reference

Assessment of photodynamic destruction of Escherichia coli o157:H7 and Listeria monocytogenes by using ATP bioluminescence

Assessment of photodynamic destruction of Escherichia coli o157:H7 and Listeria monocytogenes by using ATP bioluminescence. Romanova, N. A.; Brovko, L. Y.; Moore, L.; Pometun, E.; Savitsky, A. P.; Ugarova, N. N.; Griffiths, M. W. (Canadian Research Institute for Food Safety, University of Guelph, Guelph, ON, Can.). Applied and Environmental Microbiology, 69(11), 6393-6398 (English) 2003 American Society for Microbiology. CODEN: AEMIDF. ISSN: 0099-2240. DOCUMENT TYPE: Journal CA Section: 8 (Radiation Biochemistry) Antimicrobial photodynamic therapy was shown to be effective against a wide range of bacterial cells, as well as for fungi, yeasts, and viruses. It was shown previously that photodestruction of yeast cells treated with photosensitizers resulted in cell destruction and leakage of ATP. Three photosensitizers were used in this study: tetra(N-methyl-4-pyridyl)porphine tetratosylate salt (TMPyP), toluidine blue O (TBO), and methylene blue trihydrate (MB). A microdilution method was used to det. 7220-79-3 and 56-65-5 are cas registry numbers of chemicals which are used as reagents here. MICs of the photosensitizers against both Escherichia coli O157:H7 and Listeria monocytogenes. To evaluate the effects of photodestruction on E. coli and L. monocytogenes cells, a bioluminescence method for detection of ATP leakage and a colony-forming assay were used. All tested photosensitizers were effective for photodynamic destruction of both bacteria. The effectiveness of photosensitizers (in microgram-per-milliliter equiv.) decreased in the order TBO > MB > TMPyP for both organisms. The MICs were two- to fourfold higher for E. coli O157:H7 than for L. monocytogenes. The primary effects of all of the photosensitizers tested on live bacterial cells were a decrease in intracellular ATP and an increase in extracellular ATP, accompanied by elimination of viable cells from the sample. The time courses of photodestruction and intracellular ATP leakage were different for E. coli and L. monocytogenes. These results show that bioluminescent ATP-metry can be used for investigation of the first stages of bacterial photodestruction. .