Hawkeye-Jensen,Inc.
4408-B Pottsville Pike
Reading, Pennsylvania 19605
TEST SAMPLES:
1ppm Silver Water® solution
3ppm Silver Water® solution
20ppm Silver Water® solution
1.0% Germaben II solution
TEST:
24-hour reduction test
TEST ORGANISMS:
Esherichia Coli |
ATCC 13047 |
Pseudomonas Aeruginose |
ATCC 27853 |
Staphylococcus Aurous |
ATCC 6538 |
Candida Albicans |
ATCC 14053 |
Aspergillus niger |
ATCC 16404 |
OBJECTIVE:
To determine if any of the above test samples has the ability to be substantially
detrimental to a significant population of known organisms.
PROCEDURE:
Twenty milliliters (ml) of sample were transferred to each of five sterile, capped sample cups.
Each cup was inoculated with a calculated inoculum of approximately 1 x 10 of each of the
given microbial suspensions and mixed. Samples were taken and plated at 24 hours after inoculation.
RESULTS:
|
3ppm |
10ppm |
20ppm |
1.0% Germaben II |
E.Coli |
130 |
<10 |
50 |
<10 |
Aeruginosa |
50 |
<10 |
10 |
<10 |
Staph.Aureus |
4,000 |
750 |
370 |
2,000 |
C.Albicans |
50 |
80 |
70 |
<10 |
HOW TO READ THIS LAB TEST:
The results show and compare how much each test organism was
reduced in each product (3,10, 20 and 1.0%) in a 24-hour period.
Starting with approximately a 750,000 population of each organism, the 3ppm reduced the E.Coli 130
times, the l0ppm less than ten times, the 20ppm 50 times and the 1.0% Germaben II less than 10.
Test Organisms:
Group |
Organisms Used |
|
Ferm. Gram-neg |
Enterbacter Cloacae
Eacherichia Coli |
ATCC 13047
ATCC11775 |
Non-form.Gram-negs |
Pseudomonas Aeruginosa
Burkholderia Cepacia |
ATCC 27853
ATCC25415 |
Gram Pos. Cocci |
Staphylococcus Aureus |
ATCC 6538 |
Yeasts |
Candida Albicans |
ATCC 14053 |
Molds |
Aspergillus Niger |
ATCC 18404 |
Culture Maintenance:
Culture |
Maintenance Agar |
Storage |
Transfer Options |
Bacteria |
Trypticase Soy |
Refrigeration |
Monthly |
Yeasts |
Bactrol Disks |
Refrigeration |
As needed |
Molds |
Sabouraud Dextrose |
Refrigeration |
Monthly |
Diluents/Recovery,Media
Diluents |
Agars |
Lotheen broth |
Lotheen agar (bacteria, yeasts) |
|
Sabouraud Dextrose (molds) |
Inoculum Preps:
Culture |
Incubation |
Bactaris |
30-35 C/24-48 hrs. |
Yeasts |
same |
Molds |
20-25 C/7-14 days |
Procedure:
1. At least 20 g of product is inoculated with microbial suspension, so as to give 10 bacteria or 10 yeasts or molds per gram of product.
2. Using minimum sample size of 1 g. prepare decimal dilutions, and determine plate count/g of sample, by pour or surface plating methods.
3. Read plates after 2-3 days @ 30-35 C (bacteria/yeasts), and 3-7 days @ 20-25 C (molds).
4. Resample @ 1,2,3,7,14,28 days at ambient temp.
5. Rechallenge if specified.
Interpretation:
At least 99.9% reduction (veg. Bacteria)/90.0% reduction (molds) within 7 days. Ref: CTFA 1993 Sect. 13 pp 1-2
Challenge testing for the Burn Cream with Colloidal silver was begun on 10/22/97 for the yeast and bacteria groups (excluding Gram positive, which has not been started). And 10/30/97 for the mold group.
The yeast on bacteria groups were reduced 99.99% by day 1 and continued through day 7. The mold had a lesser percent reduction on day one however further testing must be done to make substantial claim.