Effect Of Sterilization Research Articles

Acacia mangium × A. auriculiformis micropropagation in a non-sterile environment

ABSTRACT Autoclaving eliminates microbial contamination during micropropagation, but the process is complex, time-consuming and expensive. Chemical sterilisation also effectively disinfects culture media and is relatively simple and cost-effective. Prior studies have focused on the effects of chemical sterilisation on bud induction, but the effects of sterilant on proliferation and rooting are unknown. We investigated the effect of sterilant on Acacia mangium × A. auriculiformis bud induction, rooting and subculture rooting. The optimal bud induction medium comprised 1/8 Murashige and Skoog medium + 7 g l−1 agar + 0.2 g l−1 chlorothalonil + 0.5 mg l−1 6-benzylaminopurine. The maximum bud induction rate (99.54%) with zero contamination was achieved using the third to fifth stem segments collected in October and treated with 0.8 g l−1 carbendazim for 3 min. The maximum rooting rate (97.62%) was attained using a rooting medium consisting of 7 g l−1 agar + 0.2 g l−1 chlorothalonil + 1.5 mg l−1 indolebutyric acid + 0.5 mg l−1 naphthaleneacetic acid. Proliferation ratio and subculture duration were positively correlated. The maximum proliferation rate (3.58%) was realised in the fourth subculture rooting. Chlorothalonil can effectively replace autoclaving of A. mangium × A. auriculiformis bud induction and rooting media. The present study provides insights for improving the rapid propagation method of Acacia sp. and a new direction for the development of micropropagation technology.

Effect of sterilization on the corrosion behavior of orthopedic implants coated and uncoated

The impact of sterilization on the corrosion behavior of orthopedic implants produced via Laser Powder Bed Fusion is analyzed in a biologically relevant environment. In a controlled environment at 37 °C, experiments were conducted to mimic a natural biological state. In a controlled oven at 50 °C for 20 min, AISI 316L stainless steel samples were prepped before primary testing. The experiment showed that sterilization leads to the development of a more efficient passive layer, resulting in improved corrosion resistance. The improvement in corrosion potential, pitting potential, and corrosion rate was substantial. A decrease in corrosion resistance is observed when TiN (Titanium Nitride) is applied. The findings suggest that sterilization can enhance the corrosion performance of 316L L-PBF implants, although this improvement may not apply equally to all coated components, such as those with TiN coatings.

Effect of Sterilization on the Change of Available Phosphorus During the Wetting and Drying Process

Wetting and drying are typical natural events in arid and semiarid areas. In order to explore the contribution of microorganisms to the change in soil phosphorus components during wetting and drying processes, soil incubation experiments were conducted on calcareous soil from Inner Mongolia grasslands. By comparing the change in various phosphorus fractions between sterilized and unsterilized soils, the microbial effect on the change in available phosphorus with soil moisture changes was studied. The results indicated that there was no significant difference in APi (NaHCO3-extractable inorganic phosphate) content between the two treatments. Sterilization caused the content of APo (NaHCO3-extractable inorganic phosphate) to significantly increase. These results suggested that soil microorganisms have a negligible influence on changes of soil available inorganic phosphorus (APi) in the present soil sample during the wetting and drying process. The change in APo may be related to the high-temperature and high-pressure sterilization processes. These results enrich our knowledge about the microbial influence on dynamics of soil available phosphorus during wetting and drying events.

Dry Heat Sterilization of a Pelleted, Natural Ingredient Rodent Diet.

Sterilization of rodent feed is recommended to eliminate potential murine pathogens and minimize microbial variability between batches. Most research institutions sterilize feed using steam/pressure (autoclave) or irradiation. Both methods have advantages and disadvantages that contribute to their suitability, including cost, maintenance, availability, and alterations to the exposed product. Dry heat sterilization, which has been in use for over 75 y, uses higher temperatures and longer sterilization times than steam autoclave and is most often used for delicate instruments or products that would be damaged by water such as powders or oil-based liquids. Dry heat sterilization in vivaria has been limited to date but is gaining popularity due to lower initial purchase and ongoing operational costs as compared with steam autoclaves. Little published information exists on the effects of dry heat sterilization on animal feed. We evaluated the sterility and chemical alterations of a natural ingredient, pelleted, rodent diet (NIH-31) after exposure to dry heat. Feed sterility was achieved using a dry heat exposure temperature of 160 °C (320 °F) for 4 h. This exposure resulted in a significant loss of heat-labile vitamins and significantly more acrylamide production as compared with the nonsterile, irradiated, and autoclaved feed.

Efficacy of antiseptics for rubber dam sterilization prior to endodontic treatment.

This study investigated the efficacy of various antiseptics for disinfection of rubber dams used during endodontic treatment, the duration of disinfection effectiveness, and the disinfection protocol employed by dental schools in Thailand. The efficacy of 10% povidone-iodine, 1.5% tincture iodine and 70% ethyl alcohol in eliminating Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans) on the rubber dam was investigated. Time duration of disinfection was evaluated at 0, 30, 60, and 120 min. The two-step disinfection method adopted at Thai dental school was examined. Independent t-test or Kruskal-Wallis followed by a Dunnett's test was used for statistical analysis. Among the three antiseptics, 10% povidone and 1.5% tincture iodine eradicated the microorganisms completely, whereas 70% ethyl alcohol did not achieve a statistically significant decrease. The duration of sterilization effectiveness was 120 min for 10% povidone-iodine, but bacteria were eliminated only at 0 min by 1.5% tincture iodine. The results also indicated that the two-step protocol scarcely eliminated the microorganisms. The best antiseptic for rubber dam disinfection is 10% povidone-iodine, which remains effective for 120 min. The two-step protocol typically practiced in Thai dental schools needs to be updated. The use of 10% povidone-iodine alone is adequate for complete eradication of E. faecalis and C. albicans.

Sterilization Effect of Cooking Process for Guilin Rice Noodles Based on Heat Conduction Model

Sterilization Effect of Cooking Process for Guilin Rice Noodles Based on Heat Conduction Model

PdMo bimetallene nanozymes for photothermally enhanced antibacterial therapy and accelerated wound healing.

Although antibacterial platforms involving nanozymes have been extensively investigated, there are still problems of poor reactive oxygen species generation efficiency and obstinate bacterial biofilms. Developing a nanozyme-photothermal therapy nanoplatform with superior sterilization effects and minimal side effects would be a good alternative for completely eliminating bacteria and biofilms. Herein, an ultrathin PdMo bimetallene nanozyme with a planar topology and boosted metal utilization, exhibiting excellent photothermal and peroxidase-like activity, is designed for synergistic nanozyme-photothermal sterilization applications and accelerated wound healing. The superior catalytic activity of PdMo bimetallene nanozymes could convert a biosafe concentration of hydrogen peroxide (H2O2) into large quantities of toxic hydroxyl radicals (•OH) under laser irradiation, enhancing bacterial membrane permeability and thermal sensitivity for efficient removal of bacteria and biofilms. In addition, PdMo bimetallene presents a good wound-healing ability according to the results of fibroblast proliferation and collagen deposition with minor side effects. This work would provide an innovative avenue for developing metallene-based nanozymes for biomedical applications.

Assessing the cyclic fatigue resistance and sterilization effects on replica-like endodontic instruments compared to Reciproc Blue

This study aimed to evaluate the effect of the number of uses and autoclave sterilization on the cyclic fatigue resistance of four replica-like instruments RC Blue; Only One File Blue; Recip One Blue; and Micro Blue compared to the original system Reciproc Blue (VDW, Munich, Germany). The instruments were analyzed by scanning electron microscope (SEM) before being used in root canal instrumentation (baseline). Fifty molars were instrumented by ten instruments (n=10). After sterilization in an autoclave, the instruments were analyzed by SEM. This procedure was repeated twice more using different molars, totaling 3 rounds of instrumentation, sterilization and SEM analysis. Then, ten different instruments from each brand were tested for cyclic fatigue resistance. Number of uses data were analyzed using Chi-squared analysis, and cyclic fatigue data were analyzed by one-way Anova followed by Tukey’s test as the data had normal distribution. The fracture times for all systems had no significant difference, but Micro Blue had significantly lower values than the other systems (p < 0.05). The SEM analysis showed distortions in the instruments after the 3rd use. Therefore, all tested instruments except of Micro Blue have similar resistance to cyclic fatigue, and all are reliable for use in up to 2-cases.

Review on Biological Indicator

Biological indicators (BIs) serve as crucial tools in assessing the efficacy of sterilization and disinfection processes across diverse industries, including healthcare, pharmaceuticals, and food. This review examines key features and the significance of BIs, emphasizing their microbial sensitivity, reproducibility, resistance to specific sterilization methods, and distinctive cultural characteristics. The ability of BIs to withstand stringent conditions ensures they accurately reflect the most resistant microorganisms, providing a reliable measure of sterilization effectiveness. In applications, BIs play a pivotal role in ensuring sterilization assurance in medical settings, contributing to quality control in pharmaceutical manufacturing, and safeguarding food safety in the food industry. Their importance in preventing healthcare-associated infections and maintaining product quality underscores their indispensable role in various sectors.[1] The review also highlights emerging trends in BI technology, including integration with sensors for real-time monitoring, the adoption of single-use BIs for convenience and reduced cross-contamination risks, and the customization of BIs for specific sterilization processes. These trends indicate a continual evolution in BI capabilities, enhancing their precision and utility in assessing and validating sterilization procedures. In conclusion, biological indicators are fundamental components of quality assurance programs, offering a reliable means to validate sterilization processes. As technology advances, the integration of BIs with monitoring tools is expected to further refine their accuracy and broaden their applicability across industries.[2].

Effects of thermal and nonthermal treatments on microorganisms, pyrrolizidine alkaloids and volatile compounds in oregano (Origanum vulgare L.)

Effects of steam sterilization, gamma-irradiation, UV-irradiation and ozonation on microbial inactivation, pyrrolizidine alkaloid degradation and volatile compound profile in oregano were investigated. Steam sterilization and gamma-irradiation were the most effective treatments in inactivating microorganisms. These treatments resulted in 0.87–2.15 log reductions in total aerobic mesophilic bacteria counts and reduced yeast-mold and Enterobacteriaceae counts below the detectable level. Steam sterilization caused increased levels of pyrrolizidine alkaloids (PAs) and decreased levels of their N-oxide forms (PANOs) demonstrating a simultaneous conversion of PANOs into the corresponding PAs. Ozone treatment caused significant decreases in the levels of individual and total PAs/PANOs. After ozone treatment, decreases of 54.4, 53.9, 61.6 and 61.4% were observed in the levels of europine-N-oxide, europine, lasiocarpine-N-oxide and lasiocarpine, respectively. Steam sterilization, UV-irradiation and ozone treatments significantly altered the composition of the volatile compounds of oregano as evidenced by decreased levels of major components and the formation of some new compounds.

Effect of gamma irradiation and supercritical carbon dioxide sterilization with Novakill™ or ethanol on the fracture toughness of cortical bone.

Sterilization of structural bone allografts is a critical process prior to their clinical use in large cortical bone defects. Gamma irradiation protocols are known to affect tissue integrity in a dose dependent manner. Alternative sterilization treatments, such as supercritical carbon dioxide (SCCO2 ), are gaining popularity due to advantages such as minimal exposure to denaturants, the lack of toxic residues, superior tissue penetration, and minor impacts on mechanical properties including strength and stiffness. The impact of SCCO2 on the fracture toughness of bone tissue, however, remains unknown. Here, we evaluate crack initiation and growth toughness after 2, 6, and 24 h SCCO2 -treatment using Novakill™ and ethanol as additives on ~11 samples per group obtained from a pair of femur diaphyses of a canine. All mechanical testing was performed at ambient air after 24 h soaking in Hanks' balanced salt solution (HBSS). Results show no statistically significant difference in the failure characteristics of the Novakill™-treated groups whereas crack growth toughness after 6 and 24 h of treatment with ethanol significantly increases by 37% (p = .010) and 34% (p = .038), respectively, compared to an untreated control group. In contrast, standard 25 kGy gamma irradiation causes significantly reduced crack growth resistance by 40% (p = .007) compared to untreated bone. FTIR vibrational spectroscopy, conducted after testing, reveals a consistent trend of statistically significant differences (p < .001) with fracture toughness. These trends align with variations in the ratios of enzymatic mature to immature crosslinks in the collagen structure, suggesting a potential association with fracture toughness. Additional Raman spectroscopy after testing shows a similar trend with statistically significant differences (p < .005), which further supports that collagen structural changes occur in the SCF-treated groups with ethanol after 6 and 24 h. Our work reveals the benefits of SCCO2 sterilization compared to gamma irradiation.

Combined Effects of Pressure and Ionic Strength on Protein-Protein Interactions: An Empirical Approach.

Proteins are exposed to hydrostatic pressure (HP) in a variety of ecosystems as well as in processing steps such as freeze-thaw, cell disruption, sterilization, and homogenization, yet pressure effects on protein-protein interactions (PPIs) remain underexplored. With the goal of contributing toward the expanded use of HP as a fundamental control parameter in protein research, processing, and engineering, small-angle X-ray scattering was used to examine the effects of HP and ionic strength on ovalbumin, a model protein. Based on an extensive data set, we develop an empirical method for scaling PPIs to a master curve by combining HP and osmotic effects. We define an effective pressure parameter that has been shown to successfully apply to other model protein data available in the literature, with deviations evident for proteins that do not follow the apparent Hofmeister series. The limitations of the empirical scaling are discussed in the context of the hypothesized underlying mechanisms.

The effect of sterilization and storage on the viscoelastic properties of human tendon allografts – Continued: Storage for 0 to 4 months

The role of donor-derived tendons, also known as allografts, in anterior cruciate ligament replacement surgeries is steadily increasing. Before surgery, temporary storage and, in most cases, sterilization are essential. It is, thus, crucial to determine how these procedures alter the grafts’ biomechanical properties. The purpose of this research was to analyze the effect of different sterilization methods (native, frozen, frozen + 21 kGy gamma irradiation, frozen + 21 kGy electron beam irradiation) and storage durations (0 to 4 months) on the deformation and creep of two tendon types (tibialis anterior, peroneus longus). 80 tibialis anterior and 83 peroneus longus tendons from 51 human cadavers were included. The samples were removed, placed in a radio-cryoprotectant solution, then slowly cooled, sterilized and stored at −80 °C. All groups were subject to 60 s static creep test with 250 N load. Deformation during the loading phase, creep during static loading, and the ratio of these two were evaluated.Deformation at the end of the loading phase and creep consistently exhibited significantly smaller values in the tibialis anterior compared to the peroneus longus type, as well as in electron beam-sterilized grafts as opposed to gamma beam-sterilized ones. Prolonged storage periods (within 0 to 4 months) resulted in a notable increase in these values, particularly in deformation. Based on the experimental data, the tibialis anterior tendon type and sterilization by gamma beam irradiation are better choices for anterior cruciate ligament reconstruction than the peroneus longus and sterilization by electron beam. Increased storage time affects negatively the evaluated mechanical properties.

CuFe Layered Double Hydroxide as Self-Cascade Nanoreactor for Efficient Antibacterial Therapy.

Nanozyme-induced reactive oxygen species (ROS)-dependent catalytic therapy has been developed into a powerful strategy against bacterial wound infections. However, the limited endogenous supply or instability of H2O2, the reliance on external stimuli for the generation of ROS, and the highly expressed glutathione (GSH) level make it a challenge to achieve high-performance therapeutic efficiency. In this work, a facile therapeutic strategy against bacterial infections with pristine CuFe layered double hydroxide (LDH) as the self-cascade nanoreactor is proposed without modification or additional energy input. CuFe LDH with an oxidase-like feature can catalyze the generation of multiple ROS, such as 1O2, ·O2-, and H2O2. And the self-generated H2O2 in the cascade nanoreactor could be further in situ transformed to ·OH owing to the peroxidase-like activity. As a result, the cell membrane of bacteria is destroyed, leading to death. Furthermore, its ultrahigh enzyme-like activity of CuFe LDH could effectively promote the breakdown of the biofilm structure. Additionally, the Cu2+-mediated GSH exhaustion of CuFe LDH further avoids the consumption of oxidized ROS and thereby significantly improves the sterilization effect. Finally, the as-prepared CuFe LDH with negligible side effects on normal tissues can be successfully used to eliminate the methicillin-resistant Staphylococcus aureus-infected wounds and accelerate their healing in the mouse model, which paves a new avenue as an antibacterial agent for clinical anti-infective treatment.

Effect of High-Pressure Micro-Fluidization on the Inactivation of Staphylococcus aureus in Liquid Food.

High-pressure homogenization has been extensively studied for its excellent homogenization effect and the prospect of continuous liquid food production, but its sterilization ability still needs to be improved. In this study, we replaced the homogenization valve with two opposing diamond nozzles (0.05 mm inner diameter) so that the fluid collided at high velocity, corresponding to high-pressure micro-fluidization (HPM). Moreover, HPM treatment significantly inactivated Staphylococcus aureus ~7 log in the liquid with no detectable sub-lethal state at a pressure of 400 MPa and a discharge temperature of 50 °C. The sterilization effect of HPM on S. aureus subsp. aureus was attributed to a significantly disrupted cell structure and increased membrane permeability, which led to the leakage of intracellular proteins, resulting in bacterial death. At the same time, HPM treatment was able to significantly reduce the ability of S. aureus subsp. aureus to form biofilms, which, in turn, reduced its virulence. Finally, compared to the simulated system, more effective sterilization was observed in apple juice, with its color and pH remaining unchanged, which suggested that HPM can be used to process other liquid foods.

Inhibitory effects of cold atmospheric plasma on population growth of the carob moth, Ectomyelois ceratoniae (Lepidoptera: Pyralidae) in laboratory.

Potential sterilizing effects of the atmospheric cold plasma on the carob moth, Ectomyelois ceratoniae Zeller (Lepidoptera: Pyralidae) was studied under laboratory conditions by means of life history experimentation. The results showed that the population growth parameters of the carob moth decreased in all periods of 15 to 60 sec of plasma treatments applied on 1 -day-old eggs. Overall, 19.5% and 23.8% of reproduced eggs were fertile when the experimental males and females mated with normal moths in indirect treatments of 15 and 30 sec, respectively. The highest intrinsic rate of population increase, r, was in control (0.11 day-1) and the highest decrease in this parameter was in the 30 sec direct treatment (- 0.073 day-1). The results showed that cold plasma had an acceptable potential to sterilize the pest if plasma was applied at egg stage. This potential will be explored from the perspective of insect sterility technique and the genetical / physiological mechanisms involved should be studied in future.

Sterilization of Water-Based Cutting Fluids Using Compact Air-Cooled Coaxial Dielectric Barrier Discharge Reactor with Bubbler

Odor and discoloration in water-based cutting fluids are caused by the growth of microorganisms and putrefying bacteria. This significantly reduces cutting performance, prevents rust, and deteriorates the working environment. To overcome these drawbacks, we developed a compact air-cooled coaxial dielectric barrier discharge (DBD) with a bubbler. Bacteria and microorganisms living in waste cutting fluids were sterilized by the high concentration of ozone produced under the optimized conditions of the compact air-cooled coaxial DBD. Moreover, it was confirmed that 99.99% of bacteria and microorganisms were completely removed. Ozone was found to not affect property changes such as the composition, concentration, and pH of the water-based cutting fluids. The chromaticity and complex odor of waste cutting liquids were thus found to have been improved by the effects of microorganism and bacterial sterilization. We conclude that the proposed a compact air-cooled coaxial DBD with a bubbler is an efficient method for sterilizing water-based cutting fluids.

Propelling CuCo-based nanozyme design to new heights through triple enzyme-like power for high-efficiency bacterial eradication

Bacterial infection-related diseases are a serious issue that threatens human health, and it is highly desirable to develop a high-performance antibacterial agent to combat it. Herein, copper/cobalt-based metal sulfide nanoparticles (CCS NPs) as a new kind of antibacterial nanozyme were prepared by a facile hydrothermal method. Owing to its rich chemical states, the CCS NPs with intrinsic peroxidase- and oxidase-like activities could generate reactive oxygen species (ROS) to exert bactericidal capacity. The CCS NPs could also rapidly deplete glutathione (GSH) to aggravate the oxidative stress in bacteria, thus enhancing the sterilization effect. The results showed that, with the assistance of H2O2 at low concentrations, CCS NPs possessing peroxidase-like, oxidase-like, and GSH depletion activities could achieve remarkable antibacterial effects in vitro. The in vivo implantation demonstrated that CCS NPs with triple enzyme-like activities had efficient bacteria elimination and good biocompatibility in treating bacteria-infected wounds, indicating its wide potential application in the non-antibiotic treatment of bacteria-infected wounds.

The effect of cat sterilization on the microbiome of the uterus and vagina.

The effect of cat sterilization on the microbiome of the uterus and vagina.

Sterilization of yak milk by direct steam injection (DSI) and effects on milk quality

To facilitate development of new yak milk products with high added value, sterilization effects of direct steam injection (DSI) were evaluated. The Z value (temperature increase necessary to reduce inactivation time by 90%) of Geobacillus stearothermophilus spores (ATCC 7953; 106 CFU mL−1) in yak milk was 5.88 °C. Heating of the milk above 153.86 °C for 0.116 s achieved complete inactivation of ATCC 7953 spores; i.e., commercially-acceptable sterility. The native lactoferrin and β-lactoglobulin (β-Lg) contents of the milk decreased by 40 and 30% after DSI treatment, respectively, whereas the α-lactalbumin (α-La) content did not differ significantly; the overall extent of denaturation of heat sensitive proteins was lower than in UHT milk. The furosine and lactulose contents in DSI treated yak milk were ≤1.11 mg/10 g of protein and 0.368 mg/10 mL, respectively, similar to those in pasteurized milk. The pH, Hunter color values and aroma were significantly influenced by DSI treatment, but the overall sensory acceptability of DSI treated yak milk was assessed as good. These findings indicate that DSI has great potential for producing yak milk and processed yak milk products with considerable added value.