Case Study: Inhibition of Staphylococcus Aureus by various silver products (III)
June 2001: Natural-Immunogenics Corp.
The purpose of this study was to compare and contrast the inhibition of various types of silvers on both normal and antibiotic resistant strains of Staphylococcus aureus ("Staph"). This was accomplished by inoculating healthy Staph with silver on standard YT plates, then placing them in a 37° C incubator overnight.
Materials and Methods.
Each 95mm sterile polystyrene plate was filled with 5mm of YT media consisting of 0.5% sodium chloride, 0.6% yeast extract, 0.8% tryptone and 2% agar. A small 3 mm scrape of Staph was re-suspended in sterile 18 MW lab water and diluted. To each 1 mL dilution of staph cells, 100ul of each silver was added and then left to sit for 7 minutes. After the appointed time, five 10µl spots of each diluted strain containing silver were arranged on a YT plate.
Qualitative results can easily be seen on each plate. The positive control for S-1 grew out 4.5 spots, represented by (++++½) and the positive control for S-2 grew out 4.5 spots when colloidal silver was not present (++++½). A (-) represents no Staph grew on the plate. The effectiveness of the silver products for each company can be compared by the number of spots or +’s seen in the graph.
Inhibition of Staph
Results of inhibition with various silver products at 7 Minutes
In this experiment Sovereign Silver (SS) almost totally eradicated the bacteria, while XX4A at 30ppm and XX7D at 100 ppm and 200 ppm were only partially effective. Silver nitrate and XX7D at 10 ppm appear to be only marginally effective at inhibiting the growth of Staphylococcus aureus.