AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
Exposure of Aerosolized Bacillus Spores to Combustion Products of Novel Reactive Biocidal Materials: Kinetics of Inactivation Process
SERGEY A. GRINSHPUN, Michael Yermakov, Reshmi Indugula, Atin Adhikari, Tiina Reponen, Edward Dreizin, Mirko Schoenitz, University of Cincinnati
Abstract Number: 98 Working Group: Bioaerosols
Abstract Targeting a bio-weapon facility for destruction may cause highly pathogenic bio-agents to release into the atmosphere. Some bio-agents (e.g., Bacillus anthracis spores) can remain viable even after exposure to heat in a combustion/explosion setting. As part of the bio-agent defeat program, novel halogen-containing reactive materials are being developed to inactivate stress-resistant viable microorganisms during their release. In this study, we tested two such materials, Al•I$_2 and Al•B•I$_2, with respect to the biocidal capability of their combustion products against two well-established surrogates of Bacillus anthracis: Bacillus subtilis var. niger (aka Bacillus atrophaeus or BG spores) and Bacillus thuringiensis kurstaki (Btk spores). A state-of-the-art experimental facility was used to investigate the survival of aerosolized spores. The spores were dispersed in dry airflow and exposed to the tested combustion products in a temperature-controlled environment during different time periods ranging from ~0.12 to ~2.0 s. For both species and both iodinated materials, the bioaerosol inactivation factor increased exponentially with the exposure time. The inactivation effect was more pronounced for Btk than BG spores suggesting that the former are more sensitive to the stress produced by the release of iodine during combustion of Al•I$_2 and Al•B•I$_2. It was demonstrated that the main reason of inactivation of aerosolized spores observed in our tests was their interaction with iodine in the air flow rather than exposure to heat. The data generated in this study help understand the kinetics of the spore inactivation occurring due to exposure to combustion products of halogen-containing reactive materials.
The authors thank the U.S. Defense Threat Reduction Agency for funding and Dr. Su Peiris for support and encouragement.