No abstract

The study is designed to investigate bactericidal actions of electrolyzed oxidizing water on hospital infections. Ten of the most common opportunistic pathogens are used for this study. Cultures are inoculated in 4.5 mL of electrolyzed oxidizing (EO) water or 4.5 mL of sterile deionized water (control), and incubated for 0, 0.5, and 5 min at room temperature. At the exposure time of 30 s the EO water completely inactivates all of the bacterial strains, with the exception of vegetative cells and spores of bacilli which need 5 min to be killed. The results indicate that electrolyzed oxidizing water may be a useful disinfectant for hospital infections, but its clinical application has still to be evaluated.

Propionibacterium freudenreichii subsp. shermanii is known to prevent mutations caused by various agents such as N-methyl-N'-nitro-N-nitrosoguanidine, 9-aminoacridine, 4-nitro-quinoline-1-oxide and by UV radiation in both prokaryotic and eukaryotic cells. It was also shown to prevent or repair damage caused by H(2)O(2) or UV radiation in Salmonella typhimurium and Escherichia coli, a characteristic previously designated as reactivative effect. In order to characterise this effect at the molecular level, we have purified the active component from a P. freudenreichii cell-free extract using a combination of ammonium sulfate precipitation, anion-exchange and size-exclusion chromatography. The isolated 35 kDa protein was then identified using both N-terminal and internal peptide sequencing as a cysteine synthase. The latter was localised in the P. freudenreichii proteomic map. It is constitutively expressed but also clearly induced during adaptation to detergent and heat, but not acid, stresses. The biological meaning of cysteine synthase in the context of adaptation to oxidative and non-oxidative stresses is discussed.

Summary -Cells of Propionibacterium freudenreichii subsp shermanii lower the mutagenicity of 4-nitroquinoline-1-oxide in the tester strain Salmonella typhimurium TA 100 in the modified Ames test. The bacterial adaptation to the mutagen presence in the medium is demonstrated. It is possibly Iinked to induction of an antimutagenic activity. A dialysed fraction of soluble proteins of the extract (dialysate) lowers the mutagenicity of UV-C light in Salmonella typhimurium and manifests protective and reactivative effects on UV-B-and UV-C-irradiated cells of S typhimurium, Escherichia coli and the yeast Candida guilliermondii. The reactivation does not occur alter the cell irradiation with a light of total optical spectrum and visible light. (The last was studied with the yeasts.) These data serve as an indirect indication of the dialysate proteins participation in the repair of DNA injured by UV-B and UV-C irradiation. The reactivation by dialysate occurs in E coli and the yeasts Saccharomyces cerevisiae and C guilliermondii, inactivated by heating. The reactivative activity of the dialysate was localized in its 2 subfractions that manifests in E coli inactivated not only by UV light but also by heating.

Propionic acid bacteria (PAB) possess a set of physiological and biochemical properties that allows their inclusion in probiotic compositions. Their potential resources are underestimated as yet. The list of the described probiotic characteristics of PAB must be enlarged by the addition of antimutagenic, reactivative and protective activities, first discovered by our group. Live and dead cells of PAB and Luteococcus casei as well as their cultural liquid (CL) revealed antimutagenic (AM) effect on spontaneous and induced mutagenesis. Protective and reactivative activities of Propionibacterium freudenreichii cells are bound up with the intracellular protein, identified as cystein synthase, whose synthesis is induced by some stress factors. Under unfavourable conditions leading to lysis of the majority of cells, the released protein may play a vitally important role in the cell population as a whole, supporting the existence of the species. The active protein reveals cross-reactive properties, both the protective and reactivative effects on cells of Escherichia coli and yeasts Saccharomyces cerevisiae and Candida guilliermondii. Phylogenetically close to PAB, L. casei produces and excretes in the medium a proteinaceous metabolite, possessing protective and reactivative effects on cells of the producer, E. coli, S. cerevisiae and C. scottii, treated by heating and UV irradiation. The exometabolite is synthezed by cells in the log phase of growth. The effectiveness of its impact inversely depends on the survival of microbes. CL of L. casei is considered as the source of a new prebiotic with reactivative and protective properties.