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A
Comparative Study of the Antibacterial Efficacy of
Colloidal
Silver (BP) vs. Staphylococcus aureus
(colloidal
silver samples submitted by Dr. John Stewart)
October 29, 2004
by Natural-Immunogenics
Corp.
Purpose.
The
purpose of this study was to test the inhibition of Biophysica (BP) on
both normal and antibiotic resistant strains of Staphylococcus aureus (“Staph”).
This was accomplished by innoculating healthy Staph cultures with
the colloidal 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
resuspended in sterile 18 MΩ lab water and diluted. To each 100 µl
dilution of staph cells, 10µl of silver was added and then let sit for
both 4 minutes and 8 minutes. After
the appointed time, five 10µl spots of each diluted staph strain
containing silver were arranged on a YT plate.
A.
The YT media was autoclaved and poured into sterile plates and allowed to
dry.
B.
Two strains of Staph received from the New York Hospital of Queens.
1. B14192 – wildtype/ normal strain -Renamed S-1
2. B14310 – antibiotic resistant (MRSA) -Renamed
S-2
C. A small
3 mm scrape of both S-1 and S-2 were
resuspended in 1250µl of lab pure water. Then a 10:1 dilution series was
performed on each strain.
D. Silver was added to each dilution of S-1 and S-2; the
cultures were then agitated and allowed to sit until spotted onto the YT
plate. The exposure time of each dilution to the silver was both four and
eight minutes.
E.
Silver
products used:
1. BP
-clear
a.
ppm = 24.20
b.
pH = 6.96
c.
Tyndall Effect = ++++
(out of a possible ++++)
d. Conductivity = 38 [mS]
F. Positive control plate -No colloidal silver added to S-1 or
S-2 cultures
Negative control plate -No Staph or silver added to check for
contamination
(image not included, no contamination).
G.
Plates then placed in a 37°C incubator overnight.
Results.
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
colloidal silver can be compared by the number of spots or +’s as seen
in the graph.
Inhibition of Staph @ 4 Minutes
S-1
S-2
+
control
++++½ ++++½
BP
++
+½
Inhibition of Staph @ 8 Minutes
S-1
S-2
+
control
++++½
++++½
BP
+
+
Inhibition of Staph @ 4 Minutes
S-1
S-2
+ control
BP 
Inhibition of Staph @ 8 Minutes
S-1
S-2
+
control
BP
Colloidal
Gold results
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