Evaluation of sponge wipe surface sampling for collection of potential surrogates for non-spore-forming bioterrorism agents

AIM

Evaluate the efficacy of sponge wipe sampling at recovering potential bacterial surrogates for Category A and B non-spore-forming bacterial bioterrorism agents from hard, nonporous surfaces.

METHODS

A literature survey identified seven nonpathogenic bacteria as potential surrogates for selected Category A and B non-spore-forming bacterial agents. Small (2 × 4 cm) and large (35.6 × 35.6 cm) coupons made from either stainless steel, plastic, or glass, were inoculated and utilized to assess persistence and surface sampling efficiency, respectively. Three commercially available premoistened sponge wipes (3M™, Sani-Stick®, and Solar-Cult®) were evaluated.

RESULTS

Mean recoveries from persistence testing indicated that three microorganisms (Yersinia ruckeri, Escherichia coli, and Serratia marcescens) demonstrated sufficient persistence across all tested material types. Sampling of large inoculated (≥107 CFU per sample) coupons resulted in mean recoveries ranging from 6.6 to 3.4 Log10 CFU per sample. Mean recoveries for the Solar-Cult®, 3M™ sponge wipes, and Sani-Sticks® across all test organisms and all material types were ≥5.7, ≥3.7, and ≥3.4 Log10 CFU per sample, respectively. Mean recoveries for glass, stainless steel, and ABS plastic across all test organisms and all sponge types were ≥3.8, ≥3.7, and ≥3.4 Log10 CFU per sample, respectively.

CONCLUSIONS

Recovery results suggest that sponge wipe sampling can effectively be used to recover non-spore-forming bacterial cells from hard, nonporous surfaces such as stainless steel, ABS plastic, and glass.

The Biosafety Research Road Map: The Search for Evidence to Support Practices in the Laboratory-Bacillus anthracis and Brucella melitensis

Introduction

Brucella melitensis and Bacillus anthracis are zoonoses transmitted from animals and animal products. Scientific information is provided in this article to support biosafety precautions necessary to protect laboratory workers and individuals who are potentially exposed to these pathogens in the workplace or other settings, and gaps in information are also reported. There is a lack of information on the appropriate effective concentration for many chemical disinfectants for this agent. Controversies related to B. anthracis include infectious dose for skin and gastrointestinal infections, proper use of personal protective equipment (PPE) during the slaughter of infected animals, and handling of contaminated materials. B. melitensis is reported to have the highest number of laboratory-acquired infections (LAIs) to date in laboratory workers.

Methods

A literature search was conducted to identify potential gaps in biosafety and focused on five main sections including the route of inoculation/modes of transmission, infectious dose, LAIs, containment releases, and disinfection and decontamination strategies.

Results

Scientific literature currently lacks information on the effective concentration of many chemical disinfectants for this agent and in the variety of matrices where it may be found. Controversies related to B. anthracis include infectious dose for skin and gastrointestinal infections, proper use of PPE during the slaughter of infected animals, and handling contaminated materials.

Discussion

Clarified vulnerabilities based on specific scientific evidence will contribute to the prevention of unwanted and unpredictable infections, improving the biosafety processes and procedures for laboratory staff and other professionals such as veterinarians, individuals associated with the agricultural industry, and those working with susceptible wildlife species.

Hydrogen Peroxide Vapor Decontamination of Hazard Group 3 Bacteria and Viruses in a Biosafety Level 3 Laboratory

Aim

This study aimed to validate the efficacy of hydrogen peroxide vapor (HPV) decontamination technology set up in a biosafety level 3 (BSL-3) laboratory on surrogates and hazard group 3 (HG3) agents.

Methods and Results

The HPV decontamination system (Bioquell) was assessed with both qualitative and quantitative methods on (1) spore surrogates (Geobacillus stearothermophilus, Bacillus atrophaeus, and Bacillus thuringiensis) in the BSL-3 laboratory and in the material airlock and on (2) HG3 agents (Bacillus anthracis; SARS-CoV-2, Venezuelan equine encephalitis virus [VEE], and Vaccinia virus) in the BSL-3 laboratory. Other HG3 bacteria likely to be handled in the BSL-3 laboratory (Yersinia pestis, Burkholderia mallei, Brucella melitensis, and Francisella tularensis) were excluded from the HPV decontamination assays as preliminary viability tests demonstrated the total inactivation of these agents after 48 h drying on different materials.

Conclusions

The efficacy of HPV decontamination was validated with a reduction in viability of 5-7 log10 for the spores (surrogates and B. anthracis), and for the enveloped RNA viruses. Vaccinia showed a higher resistance to the decontamination process, being dependent on the biological indicator location in the BSL-3 laboratory.

Inactivation of vegetative bacterial threat agents on environmental surfaces

Following a wide-area biological terror attack, numerous decontamination technologies, techniques, and strategies will be required for rapid remediation. Establishing an understanding of how disinfectants will perform under field conditions is of critical importance. The purpose of this study was to determine the efficacy of several liquid decontaminants, when used to inactivate vegetative biological agents on environmental surfaces. Aluminum, carpet, concrete, glass, and wood coupons were inoculated with 1×10(8) CFU of Burkholderia mallei, Francisella tularensis, Vibrio cholerae, or Yersinia pestis. Using spray-based application methods, decontamination was then attempted with pH-adjusted bleach, 1% citric acid, 70% ethanol, quaternary ammonia, or Pine-Sol®. Results indicated that decontamination efficacy varied significantly by decontaminant and organism. Materials such as wood are difficult to decontaminate, even when using sporicides. The data presented here will help responders develop efficacious remediation strategies following a large-scale contamination incident.