Extraction of Aerosol-Deposited Yersinia pestis from Indoor Surfaces To Determine Bacterial Environmental Decay

Abstract

Public health and decontamination decisions following an event that causes indoor contamination with a biological agent require knowledge of the environmental persistence of the agent. The goals of this study were to develop methods for experimentally depositing bacteria onto indoor surfaces via aerosol, evaluate methods for sampling and enumerating the agent on surfaces, and use these methods to determine bacterial surface decay. A specialized aerosol deposition chamber was constructed, and methods were established for reproducible and uniform aerosol deposition of bacteria onto four coupon types. The deposition chamber facilitated the control of relative humidity (RH; 10 to 70%) following particle deposition to mimic the conditions of indoor environments, as RH is not controlled by standard heating, ventilation, and air conditioning (HVAC) systems. Extraction and culture-based enumeration methods to quantify the viable bacteria on coupons were shown to be highly sensitive and reproducible. To demonstrate the usefulness of the system for decay studies, Yersinia pestis persistence as a function of surface type at 21°C and 40% RH was determined to be >40%/min for all surfaces. Based upon these results, at typical indoor temperature and RH, a 6-log reduction in titer would expected to be achieved within 1 h as the result of environmental decay on surfaces without active decontamination. The developed approach will facilitate future persistence and decontamination studies with a broad range of biological agents and surfaces, providing agent decay data to inform both assessments of risk to personnel entering a contaminated site and decontamination decisions following biological contamination of an indoor environment. IMPORTANCEPublic health and decontamination decisions following contamination of an indoor environment with a biological agent require knowledge of the environmental persistence of the agent. Previous studies on Y. pestis persistence have utilized large liquid droplet deposition to provide persistence data. As a result, methods were developed to deposit aerosols containing bacteria onto indoor surfaces, reproducibly enumerate bacteria harvested from coupons, and determine surface decay utilizing Y. pestis. The results of this study provide foundational methods required to evaluate surface decay of bacteria and potentially other biological agents, such as viruses, in aerosol particles as a function of surface type and environment. Integrating the data from both aerosol and liquid deposition surface decay studies will provide medical and public health personnel with a more complete understanding of agent persistence on surfaces in contaminated areas for assessment of health risks and to inform decontamination decisions.

The responses of an anaerobic microorganism, Yersinia intermedia MASE-LG-1 to individual and combined simulated Martian stresses

“…All known strains of Yersinia are non-spore forming and for some, especially virulent strains, an ability to survive in aquatic environments and in humidified soils (up to 280 days) is already known [ 41 – 43 ]. It was shown that the virulent Yersinia pestis strain CO92 can persist after short term exposure (up to one hour) on different dry surfaces like glass and steel [ 44 ].…”

Insights into complex nanopillar-bacteria interactions: Roles of nanotopography and bacterial surface proteins

“…Initially, bacteria in aqueous solution can be transported to a solid surface as aerosols [17], [18] or sedimentation [19], [20]. Under static conditions, bacterial mass transport is mostly due to sedimentation while under dynamic conditions, the mass transport is a combination of sedimentation, convection, and diffusion [20], [21].…”

Evaluation of altered environmental conditions as a decontamination approach for nonspore‐forming biological agents

“…Previous studies have examined the persistence (or natural attenuation) of nonspore‐forming bacteria (King et al ; Aune et al ; Calfee and Wendling ; USEPA ; Gut et al ) and viral select agents (Berendt and Dorsey ; Lai et al ; Graiver et al ; Sagripanti et al ; Yamamoto et al ; Pyankov et al ; Verreault et al ; Brown et al ) and have shown the ability of these agents to persist in various matrices or altered states (lyophilization) for months, however, many of these studies did not detail the effects when applied to common building fomites.…”