Efficacy of Colloidal Silver-Hydrogen Peroxide and 2-Bromo-2-nitroporopane-1,3-diol Compounds Against Different Serogroups of Legionella pneumophila Strains

Abstract

Cooling towers are considered as amplifier and disseminator sources for Legionella spp. despite preventive treatments. Information which was obtained from biocidal tests could improve the effectiveness of treatments. Therefore, the choice of appropriate biocides and the applying of biocides in correct dosages and contact times are important. Various oxidizing and non-oxidizing biocides have been investigated in vitro for their effectiveness against legionellae. Colloidal silver-hydrogen peroxide (CSHP) and 2-bromo-2-nitroporopane-1,3-diol (BNPD) biocides were selected as an example for oxidizing and non-oxidizing agents, respectively, in view of bactericidal action against different serogroups of L. pneumophila strains [serogroup 1 (S1) and serogroup 2-14 (S2)] which are isolated different cooling towers in the vicinity of Istanbul, Turkey and reference strain. In the current study, oxidizing biocide was found more effective than non-oxidizing biocide in terms of contact times, log reductions and recommended dosages. At the recommended concentrations for cooling towers (100 ppm), while CSHP compound killed all strains in 3 h contact time, BNPD compound killed S2 and reference strain in the same contact time, S1 strain after 6 h contact time. The results of the present study showed that effective biocide applications can be achieved by pre-determining minimum inhibitory concentration (MIC) and minimum contact time of different biocides to kill target bacteria.

Curative effect of hydrogen peroxide combined with silver ion disinfection on pelvic floor dysfunction

“…These are widely used in medical devices and as catalysts, etc. [ 11 ]. Compared to disinfection with hydrogen peroxide alone, disinfection with hydrogen peroxide and silver ion provides longer lasting disinfection and better bactericidal effects, requiring smaller dosages and providing higher chemical stability.…”

Evaluation of Industrial Biocides on a Novel Aspergillus versicolor TANCK-1 and Elucidation of Their Probable Biocidal Mechanism

“…TCMTB based formulation belonging to triazoles and imidazoles derivatives are most effective even at very low concentrations as 10 -11 M and they are able to disrupt the function of enzyme responsible for conversion of lanosterol to ergosterol [9]. KDDC and DBNP based formulation belongs to thiocarbamate and propionamide derivatives respectively, KDDC usually target the sterol biosynthesis resulting in the damage of cell membrane [11,12] but DBNP mode of action is not well understood and as per the limited information available, it appears that it functions by the inhibition of membranebound enzymes [13].…”