Review of Decontamination Techniques for the Inactivation of Bacillus anthracis and Other Spore-Forming Bacteria Associated with Building or Outdoor Materials

Abstract

Since the intentional release of Bacillus anthracis spores through the U.S. Postal Service in the fall of 2001, research and development related to decontamination for this biological agent have increased substantially. This review synthesizes the advances made relative to B. anthracis spore decontamination science and technology since approximately 2002, referencing the open scientific literature and publicly available, well-documented scientific reports. In the process of conducting this review, scientific knowledge gaps have also been identified. This review focuses primarily on techniques that are commercially available and that could potentially be used in the large-scale decontamination of buildings and other structures, as well as outdoor environments. Since 2002, the body of scientific data related to decontamination and microbial sterilization has grown substantially, especially in terms of quantifying decontamination effcacy as a function of several factors. Specifically, progress has been made in understanding how decontaminant chemistry, the materials the microorganisms are associated with, environmental factors, and microbiological methods quantitatively impact spore inactivation. While advancement has been made in the past 15 years to further the state of the science in the inactivation of bacterial spores in a decontamination scenario, further research is warranted to close the scientific gaps that remain.

The use of ozone gas for the inactivation of Bacillus anthracis and Bacillus subtilis spores on building materials

“…But when accounting for material interactions in the model, the species does have a significant effect (p <0.0001). This observed similarity or increase in resistance of B. subtilis to ozone gas as compared to B. anthracis is consistent with the literature in which the resistance of B. subtilis or B. atrophaeus is comparable to B. anthracis with the use of several other decontaminants [3]. We believe our study is the first to make the direct comparison between the two species relative to their resistance to ozone gas inactivation and supports the use of B. subtilis as a surrogate for B. anthracis for this decontaminant.…”

“…Postal Service [2]. Since this 2001 attack, a large body of research and development has been undertaken to evaluate decontamination techniques for this bioterrorism agent, and is reviewed here [3]. The present study builds on that research and supports the National Biodefense Strategy by verifying the efficacy of ozone gas as a decontaminant for inactivating B. anthracis spores deposited on various types of building materials.…”

“…Generally, inorganic, nonporous materials such as glass, laminate, or galvanized metal are typically easier to effectively decontaminate compared to porous and organic materials such as carpet and wood, especially when using oxidation-based sporicides such as ozone. [3] The observation that B. anthracis spores were relatively more difficult to inactivate with ozone gas on glass, galvanized metal and laminate indicates the possibility of a different inactivation mechanism involved. Ozone gas is known to react with organic matter to produce ROS (which may include hydroxyl and peroxyl radicals, and peroxides [34][35][36]), and these ROS may be sporicidal themselves.…”

“…Other research groups [12,15,16] have corroborated the finding that increasing RH levels (> 80%) improves efficacy with ozone gas. Indeed, a higher RH during fumigation with other gases [3] or with hot air [17][18][19][20] is usually associated with improved decontamination efficacy for B. anthracis spores.…”

DNA Damage Kills Bacterial Spores and Cells Exposed to 222-Nanometer UV Radiation

“…of spores of some species to cause food spoilage and human disease (1)(2)(3). Because of these spore properties, there is continuing interest in methods to inactivate spores in a safe manner while minimizing damage to either the environment or materials with which spores are associated (4)(5)(6). The need for such decontamination methods is further exacerbated by the increased prevalence of antibiotic-resistant bacteria as well as the potential use of spores of some strains of Bacillus anthracis as agents of bioterrorism or biowarfare.…”