used as carriers in UDM
AOAC Use-Dilution Method (UDM)
Disinfectant efficacy data generated using the Use-Dilution Method (UDM) of AOAC International is accepted by the U.S. Environmental Protection Agency (EPA) and Health Canada.
Separate UDM test protocols are designed to work with:
- Staphylococcus aureus (955.15)
- Salmonella enterica (955.14)
- Pseudomonas aeruginosa (964.02).
- Pseudomonas aeruginosa (964.02). Stainless steel penicyliders (Fig 1), used as representative hard nonporous inanimate surfaces, are contaminated with a test bacterial suspension and then exposed to the use-dilution of the test formulation. At the end of the contact time, each cylinder is separately placed in a tube with a recovery broth containing a neutralizer. The tubes are incubated and examined for turbidity as an indicator of bacterial growth.
The main steps in this semi-quantitative method are summarized in the flow chart above. For product registration, three production lots must be tested against each organism.
UDM has the following limitations:
- Semi-quantitative
- Operator-and technique-sensitivity may yield variable results
- Inoculum drying conditions not properly specified
- Ratio between carrier surface area and disinfectant volume too large
- Unsuitable for testing virucidal activity.
Efforts are now underway to replace UDM with quantitative carrier test protocols.
Here is some information about bibliographic and IP research of antimicrobial efficacy test.
Here you can find some additional information about this test.
Find more information about procedures of this test here.