Applied Biosafety最新文献

Background: The implementation of "no-touch" technologies such as ultraviolet (UV)-based sanitizers to effectively disinfect the air and high-touch surfaces may be important to keeping working environments and indoor public gathering places, where there may be a higher risk of infection from specific agents, safe for all occupants, particularly with the emergence of highly communicable diseases. UV technologies have been used for many years and are being revisited as one of disinfecting technology to address the SARS-CoV-2 virus that causes COVID-19. Methods: We selected over 20 relevant source documents from approximately 80 papers dating between 1985 and the present (2020) to evaluate the applicability, safety and relative contribution of ultraviolet to disinfect air and surfaces in the built environment. UV-based sanitizers have the potential for effective application when used in conjunction with other disinfecting means. Results: The efficacy of UV-based sanitizer technologies are promising but are dependent on numerous environmental, physical and technical factors. Conclusions: We believe that UV technologies should not be utilized in isolation and should be considered as an adjunct to protocol-driven standard operating procedures for cleaning and disinfection, had hygiene practices, and appropriate use of personal protective equipment (PPE).

Introduction: Use of sea water as a diluent for disinfectants has been of practical interest for control of aquaculture disease outbreaks in sea where fresh water is limited. This study evaluated the use of natural sea water (NSW), artificial sea water (ASW), or standard hard water (SHW) as a diluent for preparation of accelerated hydrogen peroxide (AHP) solutions against an avian influenza virus, a surrogate for the infectious salmon anemia virus. Methods: AHP solutions containing 0.18%, 0.35%, or 0.44% (w/w) of hydrogen peroxide (H₂O₂), corresponding to 1/40, 1/20, and 1/16 dilutions of the disinfectant concentrate, were evaluated at -20°C, 4°C, and 21°C. Results: When NSW was used as the diluent, a 0.35% H₂O₂ concentration was required to inactivate ∼6 log₁₀ virus at 21°C in a 5-min contact time. When temperature dropped to 4°C, 0.44% H₂O₂ in NSW was required to obtain a similar inactivation within a 5-min contact time. At -20°C, supplemented with antifreeze agents, the 0.44% H₂O₂ in NSW solutions produced complete inactivation of 5.4 log₁₀ virus within a 10-min contact time. In comparison, lower H₂O₂ concentrations and/or shorter contact times were needed to inactivate equal amounts of the virus at the same temperature when using SHW or ASW as a diluent to prepare disinfection solutions. Conclusion: The results suggested that NSW could be used as a diluent in disinfection solutions for virus inactivation as long as disinfectant concentrations and/or contact times are properly increased.

Introduction: Because of the nature of work conducted in veterinary laboratories and potential exposures to pathogenic microorganisms, good laboratory practices, risk assessments, biosafety, and biosecurity capacity is becoming vital. In this study, the Food and Agriculture Organization Laboratory Mapping Tool-Safety Module was applied to demonstrate its practical implementation in the assessment of biosafety and biosecurity statuses of veterinary laboratories in Nigeria.

Methods: The Laboratory Mapping Tool-Safety Module, a standardized questionnaire, systematically and semiquantitatively gathered data on 98 subcategories covering 4 areas of biosafety and biosecurity capabilities: administrative, operational, engineering, and personal protective equipment.

Results: Overall, the various areas and categories covered by the Laboratory Mapping Tool-Safety Module were weak across the board, with a mean performance of 19.5% (95% confidence interval, 14.0%-25.1%; range, 0.8%-29.6%). The weakest functionality was in emergency preparedness (0.8%; ie, emergency responses and exercises such as fire drills, spill cleanup, and biological spill kit availability). Also, many laboratories were deficient in metrology procedures, biosafety cabinets, chemical hazard containment, regular maintenance and external calibration procedures for laboratory equipment, and personnel health and safety. However, a few functionalities within individual laboratories scored above average (50%), for example, a university microbiology laboratory animal facility (100%). Interlaboratory comparison indicated that biosafety and biosecurity performance was similar across laboratories (P = .07) and did not vary by location (P = .37).

Conclusions: Significant biosafety and biosecurity improvements are needed to guarantee the health and safety of workers and the global community, efficient responses to infectious disease containment, and compliance with the Global Health Security Agenda.

Introduction: During pandemic situations like the one caused by the emergent coronavirus SARS-CoV-2, healthcare systems face the challenge of limited personal protective equipment and impaired supply chains. This problem poses a threat to healthcare workers, first responders, and the public, which demands solutions that can span the gap between institutional shortages and resupplies.

Objectives: To examine the efficacy of autoclave-based decontamination for the reuse of single-use surgical masks and N95 filtering facepiece respirators (FFRs). This method is the most readily available form of decontamination in the hospital and laboratory settings.

Methods: Three models of N95 FFRs and two procedural masks were evaluated in this study. A moist heat autoclave using four different autoclave cycles: 115°C for one hour, 121.1°C for 30 minutes, 130°C for two minutes, and 130°C for four minutes was used. After the autoclave process, the FFRs were NIOSH fit tested and particle counting was performed for both coarse particles of 5 micrometers (µM) and fine particles from 0.1µM to 1.0µM.

Results: We observed negligible alterations in the functionality and integrity of 3M 1805 and 3M 1870/1870+ N95 FFRs after three autoclave cycles. Surgical masks also showed minimal changes in functionality and integrity. The 3M 1860 FFR failed fit test after a single autoclave decontamination cycle.

Discussion and conclusion: The study finds that specific surgical masks and N95 FFR models can withstand autoclave decontamination for up to three cycles. Additionally, the autoclave cycles tested were those that could be readily achieved by both clinical and research institutions.

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is classified as a Risk Group 3 pathogen; propagative work with this live virus should be conducted in biosafety level-3 (BSL-3) laboratories. However, inactivated virus can be safely handled in BSL-2 laboratories. Gamma irradiation is one of the methods used to inactivate a variety of pathogens including viruses.

Objective: To determine the radiation dose required to inactivate SARS-CoV-2 and its effect, if any, on subsequent polymerase chain reaction (PCR) assay.

Methods: Aliquots of SARS-CoV-2 virus culture were subjected to increasing doses of gamma radiation to determine the proper dose required to inactivate the virus. Real-time quantitative polymerase chain reaction (RT-qPCR) data from irradiated samples was compared with that of the non-irradiated samples to assess the effect of gamma radiation on PCR assay.

Results: A radiation dose of 1 Mrad was required to completely inactivate 10^6.5 TCID₅₀/ml of SARS-CoV-2. The influence of gamma radiation on PCR sensitivity was inversely related and dose-dependent up to 0.5 Mrad with no further reduction thereafter.

Conclusion: Gamma irradiation can be used as a reliable method to inactivate SARS-CoV-2 with minimal effect on subsequent PCR assay.

Introduction: Ionized Hydrogen Peroxide (iHP) is a new technology used for the decontamination of surfaces or laboratory areas. It utilizes a low concentration of hydrogen peroxide (H₂O₂) mixed with air and ionized through a cold plasma arc. This technology generates reactive oxygen species (ROS) as a means of decontamination.

Objectives: The purpose of this study is to evaluate the diffusion effect of iHP and its decontamination capabilities using biological and enzyme indicators.

Methods: A gas-tight fumigation room with a volume of 880 ft³ was used for the decontamination trials. During the decontamination process, empty animal cages were placed inside to create fumigant distribution restrictions. Spore and enzyme indicators were placed in eleven locations throughout the decontamination room. Generation of iHP was done with the use of TOMI's SteraMist Environmental System and the SteraMist Solution, with 7.8% H₂O₂ at a dose of 0.5 ml per ft³.

Results: For the decontamination of 1hr, 2hrs, 6hrs, and 12hrs, the biological indicators of B. atrophaeus in Stainless Steel (SS) Disk in Tyvek envelope have an inactivation rate of 94%, 97%, 100%, and 100%, respectively. For G. stearothermophilus in SS disk and Tyvek envelope, it has 82%, 68%, 100%, and 100%, respectively and, for G. stearothermophilus in SS strips it has an effective rate of 88%, 67%, 91%, and 100%, respectively.

Conclusion: iHP inactivates spores, and the residual tAK activity indicates a gas-like fumigant diffusion due to the uniformity of the inactivation without the use of oscillating fans as the contact time is extended.

Introduction: The current COVID-19 pandemic has caused large shortages in personal protective equipment, leading to hospitals buying their supplies from alternative suppliers or even reusing single-use items. Equipment from these alternative sources first needs to be tested to ensure that they properly protect the clinicians that depend on them. This work demonstrates a test suite for protective face masks that can be realized rapidly and cost effectively, using mainly off-the-shelf as well as 3D printing components.

Materials and methods: The proposed test suite was designed and evaluated in order to assess its safety and proper functioning according to the criteria that are stated in the European standard norm EN149:2001+A1 7. These include a breathing resistance test, a CO₂ build-up test, and a penetration test. Measurements were performed for a variety of commercially available protective face masks for validation.

Results: The results obtained with the rapidly deployable test suite agree with conventional test methods, demonstrating that this setup can be used to assess the filtering properties of protective masks when conventional equipment is not available.

Discussion: The presented test suite can serve as a starting point for the rapid deployment of more testing facilities for respiratory protective equipment. This could greatly increase the testing capacity and ultimately improve the safety of healthcare workers battling the COVID-19 pandemic.