Key Considerations for Microbial Viability Measurements
Joy Dunkers, Sandra M. Da Silva, Stephanie Servetas, James J. Filliben, Guilherme L. Pinheiro, Nancy Lin
Making reliable measurements of antimicrobial killing efficacy requires careful consideration of the sources of biological variability, measurement bias and error throughout the entire workflow. For ultraviolet-C (UV-C) disinfection, killing efficacy is most commonly measured using plate counting where the log10 reduction in colony forming units (CFUs) is calculated using the inoculum CFU count before and after UV-C exposure. Although CFU counting is not a rapid diagnostic, it is fit-for-purpose for testing UV-C sources and establishing room disinfection protocols. Best practices for minimizing biological and technical error in plate counting have been established. Careful consideration of sources of variability during all experimental stages can help minimize error propagated to the final log10 reduction value. Instrument calibration, sample preparation, counting and viability measurements performed at NIST provide insights that could further improve confidence in killing efficacy results.
Conference Proceedings for Workshop on Ultraviolet Disinfection Technologies & Healthcare
Associated Infections: Defining Standards and Metrology Needs
January 14-15, 2020
Gaithersburg, MD, US
Workshop on Ultraviolet Disinfection Technologies & Healthcare Associated Infections: Defining
Standards and Metrology Needs
, Da Silva, S.
, Servetas, S.
, Filliben, J.
, Pinheiro, G.
and Lin, N.
Key Considerations for Microbial Viability Measurements, Conference Proceedings for Workshop on Ultraviolet Disinfection Technologies & Healthcare
Associated Infections: Defining Standards and Metrology Needs, Gaithersburg, MD, US, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=929444
(Accessed December 2, 2023)