Hawkeye-Jensen, Inc.  
4408-B Pottsville Pike  
Reading, Pennsylvania 19605  
(610) 921-5955
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.