Combining spore germination and heat inactivation to decontaminate materials contaminated with Bacillus anthracis spores.
T L Buhr, Z A Minter, N L Kennihan, A A Young, E L Borgers-Klonkowski, E B Osborn, M D Bohmke, S M Hamilton, M B Kimani, C T Miller, R S Mackie, J M Innocenti, M D Bensman, S D Lilly
Author Information
T L Buhr: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA. ORCID
Z A Minter: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
N L Kennihan: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
A A Young: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
E L Borgers-Klonkowski: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
E B Osborn: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
M D Bohmke: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
S M Hamilton: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
M B Kimani: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
C T Miller: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
R S Mackie: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
J M Innocenti: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
M D Bensman: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
S D Lilly: Naval Surface Warfare Center-Dahlgren Division, CBR Concepts and Experimentation Branch (B21), Dahlgren, VA, USA.
AIMS: To add a spore germination step in order to reduce decontamination temperature and time requirements compared to the current hot, humid air decontamination parameters, which are 75-80°C, ≥72 h, 70-90% RH, down to ≤60°C and ≤24 h total decontamination time. METHODS AND RESULTS: Bacillus anthracis spore germination with l-alanine+inosine+calcium dipicolinate (CaDPA) was quantified at 0-40°C, several time points and spore concentrations of 5-9 log per ml. Germination efficiency at 0-40°C was >99% at <8 log spores per ml. The temperature optimum was 20°C. Germination efficiency was significantly higher but slower at 0°C compared to ≥30°C at ≥8 log spores per ml. A single germinant application followed by 60°C, 1-h treatment consistently inactivated >2 log (>99%) of spores. However, a repeat application of germinant was needed to achieve the objective of ≥6 log spore inactivation out of a 7 log challenge (≥99·9999%) for ≤24 h total decontamination time for nylon and aircraft performance coating. CONCLUSIONS: l-alanine+inosine+CaDPA stimulated germination across wide temperature and spore concentration ranges. SIGNIFICANCE AND IMPACT OF THE STUDY: Germination expands the scope of spore decontamination to include materials from any industry sector that can be sprayed with an aqueous germinant solution.
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