Fast sterility assessment by germinable-endospore biodosimetry
1California Institute of Technology, Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, USA.
Applied and Environmental Microbiology
|October 7, 2008
Summary
A new microscopy-based assay, microEVA, rapidly detects viable Bacillus endospores in under 15 minutes. This biodosimetry method validates sterilization processes, offering a faster alternative to traditional culture-based techniques.
Area of Science:
- Microbiology
- Biotechnology
- Analytical Chemistry
Background:
- Industrial production of sterile products requires rapid hygiene validation.
- Bacillus endospores are standard biological indicators for sterilization efficacy.
- Current culture-based methods for endospore inactivation verification are time-consuming (over 2 days).
Purpose of the Study:
- To introduce a rapid, microscopy-based endospore viability assay (microEVA).
- To validate microEVA as a biodosimetry method for monitoring sterilization processes.
- To enable automated, in-line hygiene monitoring in industrial settings.
Main Methods:
- Utilized time-gated luminescence microscopy to detect single germinable endospores.
- Employed terbium-dipicolinate (Tb-DPA) luminescence triggered by DPA release during germination.
- Monitored endospore inactivation using microEVA against thermal and UV dosage.
Main Results:
- MicroEVA enumerated germinable endospores in under 15 minutes.
- Nearly identical decimal reduction values were obtained when comparing microEVA to culturing methods.
- Validated microEVA's accuracy and speed for sterilization process monitoring.
Conclusions:
- MicroEVA is a validated, rapid biodosimetry method for sterilization monitoring.
- The Tb-DPA assay enables quick assessment of endospore germinability.
- MicroEVA has the potential for fully automated, in-line industrial hygiene monitoring.
