Efficacy of oligodynamic metals in the control of bacteria growth in humidifier water tanks and mist droplets

Abstract

Antimicrobial capsules were evaluated for their effectiveness to control bacterial contamination of cool mist humidifiers. These capsules contain a mixture of silver and copper promoted alumina beads designed to release low concentrations of these oligodynamic metals into the reservoir water for bacteria control. The reservoir water and mist droplets from the humidifier units were tested for the presence of bacteria over a three-week period. A control unit (without capsule) showed significant bacterial contamination by day three, which increased throughout the three-week test period, in both the reservoir and mist droplets, whereas the antimicrobial capsules reduced contamination during the first week, and minimized the presence of bacteria, in both the reservoir water and mist droplets, to less than 2% of the control unit throughout the three-week test period. It was also observed that, after each inactive weekend, the initial discharge of bacteria via the mist droplets in the control unit was significantly higher than during daily use. However, initial bacterial discharge from the test unit following weekend inactivity never exceeded 0.5% of the control unit. In conclusion, these capsules containing oligodynamic metals are effective in controlling bacteria growth in humidifier water tanks and mist droplets.

In vitro permeability of silver nanoparticles through porcine oromucosal membrane

“…Silver nanoparticles (AgNPs) are diffusely used in food packaging, containers, toothpaste and teeth brushes, nipples and nursing bottles, water purification devices etc. 1,2,3 These particles are therefore able to come in contact with oral mucosa, whose penetration properties are not completely known. Silver is used for its good antimicrobial properties and its safe profile, 4 but in literature silver intoxication (argyria) has been described through oral route, in people who drank it for deliberate uptake, 5,6 or through skin route, when wound dressings containing…”

Antimicrobial effects of silver zeolite, silver zirconium phosphate silicate and silver zirconium phosphate against oral microorganisms

“…It has been described as being "oligodynamic" as a result of its ability to exhibit bactericidal activity at minute concentrations [1,2] . Consequently, a large number of oral healthcare products nowadays contain silver, principally due to its broad-spectrum antimicrobial effects and low toxicity to humans.…”

Efficacy of Silver Nanoparticles-Impregnated External Ventricular Drain Catheters in Patients with Acute Occlusive Hydrocephalus

“…The introduction of silver has recently become one of the preferred methods to confer microbial resiliency on biomedical materials and devices [3]. Although the efficacy of silver as an anti-infection and anticontamination agent is well established, the mechanism by which the silver ion exerts its toxicity toward bacteria is not yet fully understood [4]. This effect has been known for a long time [5] and it is postulated that the driving force of the interaction is the complexation reaction involving sulfhydryl-, aminoand hydroxyl-groups, which are present in various cellular components [6].…”