Destruction of bioweapon facilities due to explosion or fire could aerosolize highly pathogenic microorganisms. The post-event air quality assessment is conducted through air sampling. A bioaerosol sample (often collected on a filter for further culture-based analysis) also contains combustion products, which may influence the microbial culturability and, thus, impact the outcome.
In this study, the interactions between spores deposited on collection filters using two simulants of Bacillus anthracis (anthrax bacteria) and incoming combustion products of Al as well as Mg and B·Ti (common ingredient of metalized explosives) were investigated. Spores extracted from Teflon, polycarbonate, mixed cellulose ester (MCE), and gelatin filters (most common filter media for sampling of air microorganisms), which were exposed to combustion products during a short-term sampling, were analyzed.
The researchers found that aluminum combustion products surprisingly enhanced the culturability of some bacterial endospores on Teflon filters increasing the culturable count by more than an order of magnitude. Testing polycarbonate and MCE filter materials also revealed a moderate increase of culturability although gelatin did not. No effect was observed with either of the two species interacting on either filter media with products originated by combustion of Mg and B·Ti. Sample contamination, spore agglomeration, effect of a filter material on the spore survival, changes in the spore wall ultrastructure and germination, as well as other factors were explored to interpret the findings. The study raises a question about the reliability of certain filter materials for collecting airborne bio-threat agents in combustion environments.
“Culturability of Bacillus spores on aerosol collection filters exposed to airborne combustion products of Al, Mg, and B·Ti,” was published in Environmental Research.
Dr. Atin Adhikari, assistant professor for environmental health sciences at the Jiann-Ping Hsu College of Public Health Georgia Southern University was the lead author.