Comparison of the Sporicidal Activity of a Uv Disinfection Process with Three Fda Cleared Sterilants (original) (raw)
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American Journal of Infection Control, 2005
Background: Various liquid chemical products are commercially available in Mexico under sporicidal label claims. Frequently, information provided on their labels conflicts with published data on active ingredients, use concentrations, or exposure times. Objective: To evaluate sporicidal activity in 8 chemical products sold for the sterilization or high-level disinfection of medical and dental instruments. Methods: Bacillus atrophaeus ATCC 9372 spores were suspended (10 6 spores in 50 mL) in each of 4 glutaraldehyde solutions: a super oxidized solution, a hydrogen peroxide formulation, a quaternary ammonium compound, and an ortho-phthalaldehyde solution. After up to a 10-hour exposure, the solutions were passed through 0.22-mm filters, which were then rinsed with 1% sodium bisulfite, washed, and incubated on tryptic soy agar for 5 days at 37°C. Results: At the use concentrations stipulated on their labels, only 2 of 6 products registered as sterilants showed sporicidal activity when challenged with 6 log 10 : a 2% glutaraldehyde in 10 hours and the hydrogen peroxide solution in 6 hours. Of 2 products registered as high-level disinfectants, only the ortho-phthalaldehyde showed noticeable sporicidal activity after 10-hour exposure. Conclusion: The results show that some chemical products, commercially available in Mexico as ''Liquid Chemical Sterilants/High-Level Disinfectants'' cannot be used reliably to process instruments between patients.
Frontiers in public health, 2018
Spore-forming pathogenic bacteria, such as , are associated with nosocomial infection, leading to the increased use of sporicidal disinfectants, which impacts socioeconomic costs. However, can be prevented using microorganisms such as , a prophylactic agent that has been proven to be effective against it in recent tests or it can be controlled by sporicidal disinfectants. These disinfectants against spores should be evaluated according to a known and recommended standard. Unfortunately, some newly manufactured disinfectants like Bioxy products have not yet been tested. ASTM E2197-11 is a standard test that uses stainless steel disks (1 cm in diameter) as carriers, and the performance of the test formulation is calculated by comparing the number of viable test organisms to that on the control carriers. Surface tests are preferable for evaluating disinfectants with sporicidal effects on hard surfaces. This study applies improved methods, based on the ASTM E2197-11 standard, for evalua...
Sterilization using Germicidal UV Light
CSVTU Research Journal on Engineering and Technology, 2021
Healthcare-associated infections (HAIs) can be caused by microorganisms present in common practice instruments generating major health problems in the hospital environment. The aim of this work was to utilize the disinfection capacity of a portable ultraviolet C equipment (UV Sanitizer Box and UV-C Sterilization Torch) developed to disinfect different objects. Pollution of the macro and micro environment has caused concerns for decades and in recent times the macro consequences have been subjected to agreed international protocols, aimed at reducing pollution. As conclusion, UV-C Sanitizer Box and UV-C Sterilization Torch was effective disinfecting the most contaminated surfaces, being a promising alternative for disinfecting hospital materials and inanimate objects that cannot be immersed in liquid biocides, reducing the risk of pathogen transmission.
PDA Journal of Pharmaceutical Science and Technology, 2011
The aim of the present investigation was to evaluate the microbial efficacy against highly resistant bacterial spores on different substrates using the lowest effective concentration of a market liquid sporicide based on peracetic acid. The validation was carried out following modified European regulatory agencies procedures or test methods and USP guidelines, employing carriers of materials usually treated with the sporicidal solution and present in grade A cleanrooms and spores of four different microorganisms: Bacillus subtilis and Clostridium sporogenes, both from the ATCC collection, and Bacillus cereus and Bacillus sphaericus as environmental isolates. A statistical evaluation of data was made to estimate the variance for different study conditions. The experiments highlighted that 70% suitable dilution of the ready-to-use peracetic acid solution was effective in both clean and dirty conditions, showing at least 2 log spore reduction after treatment. To obtain effective sporicidal action on the surfaces in cleanrooms it is sufficient to use a sporicidal solution with a ready-to-use concentration of 70% while ensuring a contact time of 10 min. In any case, the reduction of sporicide concentration ensures a high degree of disinfection and provides a consumption savings. Wide-spectrum disinfectants are used in the pharmaceutical industry for the decontamination of work surfaces and equipment, but these products have some degree of toxicity for operators. This work arises from the needs of pharmaceutical companies to find the lowest effective concentration of sanitizers in order to reduce toxicity to personnel. The sanitizer used in the study was a market liquid sporicide based on peracetic acid. When we started our work no similar studies were reported in the literature, so we took European regulatory agencies and USP guidelines as a starting point, employing carriers of hard, non-porous materials usually treated with the sporicidal solution and present in sterile rooms and spores of four different microorganisms. The experiments highlighted that it is sufficient to use a 70% sporicidal solution concentration with a contact time of 10 min to reduce the number of spores to acceptable values for medicinal production. The reduction of sporicide concentration both ensures a high degree of disinfection and provides a safer working environment and consumption savings.
Comparative Sporicidal Effects of Disinfectants after Release of a Biological Agent
Military Medicine, 2007
Because of spore formation, Bacillus anthracis is considered the most resistant biological warfare agent known. The present study aimed to assess and compare well-known decontamination routes to inactivate the spores on daily-use environmental tools contaminated previously. To simulate the agent, Bacillus atrophaeus was used. Various environmental samples (such as tile, fabric clothing, wood, protective suit, glass, paper, soil, water, plastic, and metal) that may be contaminated after a biological incident were used as test carriers and inoculated with B. atrophaeus. Sodium hypochlorite, free chlorine, autoclaving, ethylene oxide, hydrogen peroxide, ultraviolet irradiation, and boiling decontaminated the samples. Glutaraldehyde (2%) and free chlorine solution (10,000 mg/L) were also found to be effective in decontaminating the samples and are recommended as alternatives to the use of sodium hypochlorite solution. Soil, tile, paper, and metal were determined to be the most difficult materials to decontaminate. It was concluded that 5% hypochlorite adjusted with acetic acid might also be used for decontamination. Decontamination strategies to reduce contamination of the environment by biological warfare agents need to be applied to mitigate the number of victims, in terms of prominent characteristics like cost-effectiveness and user-friendliness.
American Journal of Infection Control, 1998
Objective: This study was undertaken to evaluate the efficacy of 4 new low-temperature sterilization technologies: ethylene oxide with hydrochlorofluorocarbons, a liquid peracetic acid immersion system (Steris System 1 Processor), and 2 plasma sterilization processes that use vaporized hydrogen peroxide (Sterrad 100 and the Sterrad 100S). The Sterrad 100S system potentially improves sterilizer efficacy by using 2 cycles of a diffusion stage and a plasma stage per sterilization cycle.Methods: Flat stainless steel carriers were inoculated with approximately 106Bacillus stearothermophilus spores. These carriers were aseptically placed in the middle of 40 cm long stainless steel lumens (hollow tubes). Two types of lumen were used: (1) a lumen test unit with a removable 5 cm center piece (1.2 cm diameter) of stainless steel sealed to the narrower steel tubing by hard rubber septums and (2) a straight lumen. Three different diameters of the lumen test unit (1, 2, and 3 mm) and a single diameter of the straight lumen (3 mm) were studied. At least 40 replicates were performed for each type of lumen and sterilization method. After inoculation, the test unit was evaluated in 1 of the low-temperature sterilization technologies. After sterilization, the carriers were cultured in trypticase soy broth for 14 days at 55°C and assessed for growth of B stearothermophilus spores.Results: Our results demonstrated that ethylene oxide with hydrochlorofluorocarbons, the Sterrad 100S, and the Sterrad 100S half cycle were highly effective in killing approximately 106B stearothermophilus spores present in the center of narrow-lumen stainless steel tubes. As the lumen diameter decreased with the lumen test unit, the Sterrad 100 demonstrated reduced ability to kill B stearothermophilus spores present on the carrier. At the smallest diameter tested (1 mm), the Sterrad 100 system failed 74% of the time. The Steris System 1 was not effective in completely eliminating the 106 inoculum under test conditions.Conclusion: The Sterrad 100S was significantly superior to the Sterrad 100 system and equivalent to ethylene oxide with hydrochlorofluorocarbons. Introduction of this new Sterrad 100S system should improve the margin of safety and reduce processing costs by its use of a shorter cycle time. The Steris System 1 is limited by diffusion of the chemical sterilant into the interior of the lumen test unit. (AJIC Am J Infect Control 1998;26: 393-8)