ASTM E2871-21. Test Method for Determining Disinfectant Efficacy Against Biofilm Grown in the CDC Biofilm Reactor Using the Single Tube Method.
Test not accredited yet in our laboratory
Biofilms are surface-associated communities of microorganisms encased in a protective matrix of highly hydrated extracellular polymeric substances (EPS). Biofilm formation is a key strategy that microorganisms use to adapt to changing environments. Once biofilms are formed, they are difficult to remove because the EPS is firmly attached to the surface and can block access of antimicrobial agents to individual cells. Microbial biofilm control remains a major challenge for many industries, including the food, medical device and pharmaceutical industries.
The ASTM E2871 standard describes a test to evaluate the efficacy against of a liquid disinfectant against a bacterial biofilm grown in a CDC biofilm reactor, using the Single Tube method. Pseudomonas aeruginosa or Staphylococcus aureus biofilms are grown in the CDC bioreactor on carriers, biofilm growth surfaces (coupons). Carriers with mature bacterial biofilms are removed from the bioreactor and transferred to conical tubes, one per carrier. Subsequently, 5 carriers are treated with the test disinfectant, at the requested concentration, while 3 control carriers are treated with buffered dilution water. The treatment is performed during the time selected by the client, at room temperature (21°C± 2°C). After the contact time, an appropriated neutralizer is added to the tubes to stop the disinfectant activity. The biofilm from each carrier is then removed and the clumps disaggregated through vortexing and sonication. The bacterial suspension obtained from each carrier is serially diluted, and the number of viable bacteria is counted on agar plates. The log reduction in viable bacteria after the exposure to the disinfectant is calculated comparing the viable bacteria recovered from control carriers and treated carriers.