Reaerosolization of Bacillus spp. in Outdoor Environments: A Review of the Experimental Literature

Abstract

Reaerosolization or resuspension-that is, the reintroduction of previously airborne particles into the atmosphere-is a complex phenomenon. Microbial reaerosolization is particularly poorly understood because few studies have been done in this area, and many of the studies that have been performed are not in the peer-reviewed literature. The reaerosolization of Bacillus anthracis in outdoor environments is of particular concern because of its stability and potential for use as a biological weapon. This review pulls together data from more than 30 publications, spanning field and laboratory experiments, to summarize the current state of our understanding of Bacillus spp. reaerosolization in outdoor environments.

Re-aerosolization ofBacillus thuringiensisspores from concrete and turf

“…; Layshock et al . ) and the medical history of the patient can be critical. Nevertheless, one point of view is that the criterion for effective clean‐up following release of a bacterial agent of concern is that no viable particles should be recoverable (Thomas et al .…”

“…A number of outdoor evaluations of re‐aerosolization of bacterial spores have been carried out in the last 70 years (reviewed in Layshock et al . ). Those that were conducted outdoors had to contend with the problems of conducting experiments and collecting data under field conditions.…”

Rapid detection of Bacillus spore aerosol particles by direct in situ analysis using MALDI-TOF mass spectrometry

“…Weaponized BWAs are expected to be 2–10 μ m, a size that maximizes lethality and allows them to reside in the atmosphere for extended periods, spread easily and penetrate deeply into the lungs (Primmerman ; Layshock et al . ). Therefore, in this study, a bioparticle generator was developed to generate aerosol particles of 2–10 μ m. The particles were collected, concentrated and then applied using our direct in situ analysis method.…”

“…This method allows for the discrimination of B. anthracis Sterne spores, an attenuated strain (DpXO2), from the spores of other Bacillus species, specifically B. cereus and B. thuringiensis, which Letters in Applied Microbiology 59, 177--183 © 2014 The Society for Applied Microbiology are not easily distinguishable by other methods because of their high degree of phenotypic similarity and their phylogenetic relationship (Jeong et al 2013). Weaponized BWAs are expected to be 2-10 lm, a size that maximizes lethality and allows them to reside in the atmosphere for extended periods, spread easily and penetrate deeply into the lungs (Primmerman 2000;Layshock et al 2012). Therefore, in this study, a bioparticle generator was developed to generate aerosol particles of 2-10 lm.…”

The impact of inducing germination ofBacillus anthracisandBacillus thuringiensisspores on potential secondary decontamination strategies

“…Germinated B. anthracis spores were demonstrated to cause significantly less disease in mice compared to ungerminated spores (McKevitt et al 2007;Cote et al 2009). Thus, germinating/germinated spores should pose less of a threat to first responders at a contaminated site allowing for potentially safer secondary decontamination and may also mitigate risk associated with re-aerosolization events (Layshock et al 2012). This current study aimed to characterize the vulnerability of germinated spores from B. anthracis and B. thuringiensis suspended in nutritionally limited solutions, as well as secondary decontamination methods including bleach, hydrogen peroxide, formaldehyde and UV radiation.…”