Applied Biosafety最新文献

Objective: The objective of this study was to evaluate whether a Class II type A2 biosafety cabinet in a laboratory could be decontaminated while the laboratory was being fumigated using vaporous hydrogen peroxide or peracetic acid dry fogging.

Methods: To validate decontamination of all parts of the biosafety cabinet, biological indicators were placed at various locations within the biosafety cabinet, including between the pleats of supply and exhaust HEPA filters. To assess whether the operational status of the biosafety cabinet influenced the outcome of its decontamination, fumigation validations were undertaken with the cabinet running and not running. The amount of fumigant and the duration of fumigation remained constant whether the biosafety cabinet was running or not.

Discussion: Biosafety cabinet decontamination was successful only when the cabinet was running to facilitate the fumigant's circulation within the plenums and across the HEPA filters. This study shows both vaporous hydrogen peroxide and peracetic acid dry fogging can be used successfully to decontaminate Class II type A2 biosafety cabinets during laboratory fumigation, provided the biosafety cabinets are operational and running during the fumigation.

Introduction: The performance of 2 disinfectant chemicals, peracetic acid (PAA) and hypochlorous acid (HOCl), was evaluated using a Venturi-nozzle-based light decontamination system (LDS) for delivery. The atomization equipment combined low-pressure air and disinfectant via a handheld lance, producing a fine, dense aerosol. A range of microorganisms, including Bacillus cereus and Bacillus anthracis (Vollum) spores, were used as test challenges to evaluate chemicals and equipment.

Methods: The tests undertaken included assessments over fixed and variable exposure times, use of multiple surface materials, and a live agent challenge.

Results: Over a fixed-time exposure of 60 minutes, aerosolized PAA gave 7- to 8-log reductions of all test challenges, but HOCl was less effective. Material tests showed extensive kill on most surfaces using PAA (≥6-log kill), but HOCl showed more variation (4- to 6-log). Testing using B. anthracis showed measurable PAA induced spore kill inside 5 minutes and >6-log kill at 5 minutes or over. HOCl was less effective.

Discussion: The results demonstrate the importance of testing decontamination systems against a range of relevant microbiological challenges. Disinfectant efficacy may vary depending on product choice, types of challenge microorganisms, and their position in a treated area. The most effective disinfectants demonstrate biocidal efficacy despite these factors.

Conclusion: The data confirmed PAA as an effective disinfectant capable of rapidly killing a range of microorganisms, including spores. HOCl was less effective. The LDS system successfully delivered PAA and HOCl over a wide area and could be suitable for a range of frontline biosecurity applications.

Introduction: Most animal handling procedures are associated with injuries among veterinary staff and laboratory animal researchers. However, much of the currently available animal handling equipment is inadequate, limiting access to the treated animal or making workflow cumbersome. Moreover, restraining animals to perform procedures, such as blood collection or injection, elicits stress in both the animal and the worker. Herein, we present 4 home-built restraint and blood collection devices in extensive use in our institute.

Methods: Animal laboratory workers and experienced veterinarians regularly using the devices (n = 14) were asked to complete a survey ranking the contribution of the devices to worker safety and procedural efficiency.

Results: The overwhelming majority of responders (≥75%) associated all 4 devices with substantial improvements in worker safety and procedural efficiency. There were no reports of impaired workflow or safety when using the devices.

Discussion: Infection and exposure control may be implemented on various levels, including use of safer procedures, such as injection and blood collection devices. The presented intuitive handling and restraint devices allow the animal worker/researcher to perform various procedures safely and efficiently while eliciting less animal and worker stress. The devices can be easily adjusted to accommodate animal size and disease status.

Conclusion: The current devices will serve as prototypes for design of devices for larger laboratory animals.

Introduction: Formaldehyde is still the method of choice for fumigation of rooms and HEPA filters at high- and maximum-containment facilities because of its proven track record and low cost. However, formaldehyde has been shown to be carcinogenic and should ideally be replaced by other, less hazardous methods. This change has in part been hampered by the relatively high cost of alternative methods.

Methods: Here, we provide examples of room fumigations using aerosolized hydrogen peroxide showing not only that it can be used economically but also that it is a versatile method and may be used under circumstances not normally suited for fumigation.

Results and discussion: Four examples of fumigation setups are presented that illustrate the versatility, ease of use, and adaptability of aerosolized hydrogen peroxide as a fumigant. In addition, we demonstrate that aerosolized hydrogen peroxide passes through HEPA filters in biological safety cabinets and individually ventilated cage racks.

Conclusions: Considering that the fumigation method presented here is simple and highly effective, we expect it to serve as a relatively cost-effective alternative to formaldehyde fumigation for disinfecting potentially contaminated rooms and surfaces.

Introduction: There are vast differences in the size, scope, and needs of institutions that conduct research involving biohazardous materials, thus resulting in vast differences among Institutional Biosafety Committees (IBCs) and biosafety programs.

Methods: A benchmarking survey of IBC and biosafety programs was conducted in an effort to identify common practices in the field and compare this information with that of the other institutional bioethics committees, namely, Institutional Animal Care and Use Committees (IACUCs) and Institutional Review Boards (IRBs).

Objectives: The primary objectives of the survey were to assess the organizational structure of IBC and biosafety programs, determine the scope of IBC review, and compare the size of IBC and biosafety programs with that of IACUCs and IRBs.

Results: The survey results showed that IBCs most commonly reside under the same administrative unit as the IACUC and IRB, while the majority of institutions' biosafety officers report to a different unit. The majority of respondents indicated their IBC reviews research utilizing biological hazards beyond what is required by the National Institutes of Health Guidelines. The survey data suggest that IBCs have fewer support staff than the other bioethics committees; 57% of institutions report one or more full-time employee (FTE) dedicated to support the IBC, compared to 86%, 85%, and 83% of institutions that reported one or more FTE to support the IACUC, the IRB, and the biosafety program, respectively.

Conclusion: Data from the survey identified common practices among IBCs and provides institutions a tool to compare their program with others.

Introduction: High temperature alkaline hydrolysis (AH) is recognized as an alternative method for sterilization and disposition of animal carcasses and human remains. The aim of this study is to validate the low temperature (LT) AH process specific to its use in the Bio-Response Solutions, Inc. Human-28 LT System.

Methods: A 313-lb pig was processed using the manufacturers recommended cycle parameters. Stainless steel sample vials containing spore suspensions of Geobacillus stearothermophilus were implanted into the pig's deep tissue to validate the efficacy of the process conditions. Spore suspensions of Bacillus thuringiensis were suspended in the vessel headspace to validate sterilization. The spore challenge was greater than the recommended 10⁶ log used to determine sterilization. MALDI-TOF mass spectrometry analysis was used to validate the destruction of prion-sized particles in processed effluent.

Results: Complete inactivation of spores and digestion of animal tissue were achieved after processing in the Bio-Response Solutions Human-28 LT Alkaline Hydrolysis System. Complete inactivation of spores was achieved when exposed to heat in the animal carcass and headspace. No peptide fragments larger than 2500 Da were observed in the treatment effluent.

Discussion: The Bio-Response Solutions, Inc. Human-28 LT Alkaline Hydrolysis System was as effective as high-temperature alkaline hydrolysis for use on animal and human tissue.

Conclusion: LT AH for tissue and bodies exceeded the sterility assurance level III of the US State and Territorial Association on Alternative Treatment Technologies and sterility requirements for animal biosafety level-3 and -4 facilities. LT AH process validated destruction of prion-sized particles.