Omnicide MRSA Time Kill

Study Title
Antibacterial Activity and Efficacy of SteriWeb Medical, LLC Test Substance Using a Suspension
Time-Kill Procedure
Test Method

ASTM International Method E2315
Assessment of Antimicrobial Activity using a Time-Kill Procedure

Study Identification Number

Study Sponsor
Bert Rosenthal
6715 NE 63rd Street, Suite 417
Vancouver, WA 98661-1980

Test Facility
Antimicrobial Test Laboratories
1304 W. Industrial Blvd
Round Rock, TX 78681
(512) 310-8378

History of the Laboratory
Antimicrobial Test Laboratories was launched in 2006 to provide testing services to the antimicrobial industry. The company has grown considerably since then but its focus remains the same: Test antimicrobial agents, test them well, and test them fast! Antimicrobial Test Laboratories operates a 15,000+ square foot facility near Austin, Texas, where hundreds of studies are conducted annually by a staff of friendly, knowledgeable, and experienced microbiologists and virologists.

Laboratory Qualification Statement
Antimicrobial Test Laboratories was founded by microbiologist Dr. Benjamin Tanner. The laboratory ensures consistent, reproducible results by utilizing a well-trained and educated scientific staff who work from a comprehensive system of Standard Operating Procedures, official standard methods from ASTM, AOAC, and other organizations, and custom study protocols. The laboratory provides testing services to dozens of Fortune 500 companies and has been inspected for GLP compliance by the US government.

Scientist Qualifications
nick2Your Study was designed, conducted and reported by: Nicholas Garcia, B.S.

Nicholas graduated from Texas A&M University with a Bachelors of Science in Biomedical Science.

Nicholas is an experienced microbiologist with a keen eye for documentation and experimental quality. He has taken part in or overseen hundreds of studies and mastered several test methods. He takes on new projects with enthusiasm and can be counted on to see them through to completion. Nick is known in the laboratory as a hardworking, ethical professional with an upbeat attitude.

If you have any questions about your study, please don’t hesitate to contact Nicholas at:
 or (512) 310-8378

ASTM E2315: General Information
ASTM International, formerly the American Society for Testing and Materials (ASTM), is an internationally recognized organization that develops and publishes product and testing standards. ASTM E2315 is a quantitative test method designed to assess changes in the population of microorganisms in an antimicrobial liquid suspension. The method is versatile and can be conducted using contact times ranging from ten seconds to 24 hours. The ASTM E2315 test method uses non-antimicrobial agents as controls to establish baselines for microbial reductions. Because ASTM E2315 allows a great degree of latitude with regard to how the procedure is carried out, some scientists consider it to be more similar to a testing guideline than a test method.

Laboratory Qualifications Specific to ASTM E2315
Antimicrobial Test Laboratories began conducting the ASTM E2315 test method in 2007. Since then, the laboratory has performed thousands of ASTM E2315 tests on a broad array of test substances, against a myriad of bacterial, fungal, and viral species. The laboratory is also experienced with regard to modifying the method as appropriate to accommodate unique test substances. Every ASTM E2315 test at Antimicrobial Test Laboratories is performed in a manner appropriate to the test substance submitted by the Study Sponsor, while maintaining the integrity of the method.

Study Timeline

jar2Test Substance Information
The test substance was received on 22 AUG 2014 and the following picture was taken.

Test Substances Received: Omnicide Ointment Formula# LM-100-142A

Test Substances arrived ready to use for the conduct of the Study. Test substances were not diluted for the Study.

cualter-117x121 Test Microorganism Information
The test microorganism(s) selected for this test:

Staphylococcus aureus (MRSA) 33592
This bacteria is a Gram-positive, cocci shaped, aerobe which is resistant to the penicillin-derivative antibiotic methicillin. MRSA can cause troublesome infections, and their rapid reproduction and resistance to antibiotics makes them more difficult to treat. MRSA bacteria are resistant to drying and can therefore survive on surfaces and fabrics for an extended period of time and therefore makes this bacteria an excellent representative for antimicrobial efficacy testing on surfaces.

Diagram of the Procedure

Summary of the Procedure

  • Test microorganisms are prepared in liquid culture medium for bacteria or on agar for fungi.
  • The suspension of test microorganism is standardized, as needed, by dilution in a buffered saline solution.
  • Test and control substances are dispensed in identical volumes to sterile vessels.
  • Independently, Test and Control substances are inoculated with each test microorganism, then mixed and incubated.
  • Control substances are immediately harvested and represent the concentration present at the start of the test, or time zero.
  • At the conclusion of the contact time, a volume of the liquid test solution is harvested and chemically neutralized.
  • Dilutions of the neutralized test solution are assayed using appropriate growth media to determine the surviving microorganisms at the respective contact times.
  • Reductions of microorganisms are calculated by comparing initial microbial concentrations to final microbial concentrations.


Criteria for Scientific Defensibility of an ASTM E2315 Study
For Antimicrobial Test Laboratories to consider a Suspension Time Kill study to be scientifically defensible, the following criteria must be met:

  1. The average number of viable fungi recovered from the time zero samples must be approximately 1 x 106 cells/ml or greater.
  2. Ordinary consistency between replicates must be observed for the time zero samples.
  3. Positive/Growth controls must demonstrate growth of appropriate test microorganism.
  4. Negative/Purity controls must demonstrate no growth of test microorganism.

Passing Criteria
ASTM International does not specify performance criteria, therefore it may be established by the Study Sponsor.

Test Substance Volume: 10 ml
Control Substance Volume: 10 ml

Culture Dilution Media: N/A
Inoculum Concentration: 106 CFU/ml
Contact Time: 30 seconds, 2 minutes
Neutralizer (Vol.): Letheen Broth (19 ml)
Enumeration Plate Incubation Temperature: 36°C ± 1°C

Replicates: TWO
Control Substance: PBS

Inoculum Volume: 0.200 ml
Contact Temp.: Ambient (25°C ± 2°C)
Volume Harvested: 1.0 ml
Plating Media: Tryptic Soy Agar
Enumeration Plate Incubation Time: ~48 hours

Study Modifications
No further modifications were made to the method for this study.

Study Notes
In order to aide in inoculation, aliquots of test substance were warmed in a water bath prior to inoculation.

Study Photographs
No photographs were taken during this study.

Control Results
Neutralization Method: Validated
Growth Confirmation: Colony morphology on TSA
Media Sterility: Sterile


B = Number of viable test microorganisms in the control substance immediately after inoculation A = Number of viable test microorganisms in the test substance after the contact time


B = Number of viable test microorganisms in the control substance immediately after inoculation A = Number of viable test microorganisms in the test substance after the contact time

Results of the Study


The limit of detection for this assay is 1.00E+01 CFU/ml. Values below the limit of detection are noted as <1.00E+01 in the table and zero in the chart.

The results of this study apply to the tested substances(s) only. Extrapolation of findings to related materials is the
responsibility of the Sponsor.

Copyright © Antimicrobial Test Laboratories, 2014. Reproduction and ordinary use of this study report by the entity listed as “Sponsor” is permitted. Other copying and reproduction of all or part of this document by other entities is expressly prohibited, unless prior permission is granted in writing by Antimicrobial Test Laboratories.

Download PDF

*Testimonials appearing on this site are received via electronic feedback through verified customers. They are individual experiences, reflecting real life experiences of those who have used our products in some way or other. However, they are individual results and results will vary. We do not claim that every consumer will achieve the same results, but can verify that our laboratory tests were executed in a FDA certified contract laboratory. The testimonials are not necessarily representative of 100% of those who will use our products. Additionally, these testimonials are not intended to make claims that these products can be used to diagnose, treat, cure, mitigate or prevent any disease. The claims of eliminating 99.99% of all bacteria have not been clinically proven and evaluated by the FDA, anything beyond these have not been fully evaluated by the FDA. The contents of, such as text, graphics, images and other material contained on the Steriweb Site ("Content") are for informational purposes only. The Content is not intended to be a substitute for professional medical advice or diagnosis. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Please do not disregard professional medical advice or delay seeking it because of information you have read on