Disinfection Byproducts of Haloacetaldehydes Disrupt Hepatic Lipid Metabolism and Induce Lipotoxicity in High-Fat Culture Conditions.

Unhealthy lifestyles, obesity, and environmental pollutants are strongly correlated with the development of nonalcoholic fatty liver disease (NAFLD). Haloacetaldehyde-associated disinfection byproducts (HAL-DBPs) at various multiples of concentrations found in finished drinking water together with high-fat (HF) were examined to gauge their mixed effects on hepatic lipid metabolism. Using new alternative methods (NAMs), studying effects in human cells in vitro for risk assessment, we investigated the combined effects of HF and HAL-DBPs on hepatic lipid metabolism and lipotoxicity in immortalized LO-2 human hepatocytes. Coexposure of HAL-DBPs at various multiples of environmental exposure levels with HF increased the levels of triglycerides, interfered with de novo lipogenesis, enhanced fatty acid oxidation, and inhibited the secretion of very low-density lipoproteins. Lipid accumulation caused by the coexposure of HAL-DBPs and HF also resulted in more severe lipotoxicity in these cells. Our results using an in vitro NAM-based method provide novel insights into metabolic reprogramming in hepatocytes due to coexposure of HF and HAL-DBPs and strongly suggest that the risk of NAFLD in sensitive populations due to HAL-DBPs and poor lifestyle deserves further investigation both with laboratory and epidemiological tools. We also discuss how results from our studies could be used in health risk assessments for HAL-DBPs.

Nanoscale Sequential Reactor Design Achieves Effective Removal of Disinfection Byproduct Precursors in Catalytic Ozonation.

Transforming dissolved organic matter (DOM) is a crucial approach to alleviating the formation of disinfection byproducts (DBPs) in water treatment. Although catalytic ozonation effectively transforms DOM, increases in DBP formation potential are often observed due to the accumulation of aldehydes, ketones, and nitro compound intermediates during DOM transformation. In this study, we propose a novel strategy for the sequential oxidation of DOM, effectively reducing the levels of accumulation of these intermediates. This is achieved through the development of a catalyst with a tailored surface and nanoconfined active sites for catalytic ozonation. The catalyst features a unique confinement structure, wherein Mn-N4 moieties are uniformly anchored on the catalyst surface and within nanopores (5-20 Å). This design enables the degradation of the large molecular weight fraction of DOM on the catalyst surface, while the transformed smaller molecular weight fraction enters the nanopores and undergoes rapid degradation due to the confinement effect. The generation of *Oad as the dominant reactive species is essential for effectively reducing these ozone refractory intermediates. This resulted in over 70% removal of carbonaceous and nitrogenous DBP precursors as well as brominated DBP precursors. This study highlights the importance of the nanoscale sequential reactor design and provides new insights into eliminating DBP precursors by the catalytic ozonation process.

Relationship between chlorine decay and nanobubble application in secondary treated wastewater.

There has been numerous research on the uses of treated wastewater that needs chlorine disinfection, but none have looked at the impacts of injecting nanobubbles (NBs) on the decomposition of residual chlorine. Gas NB injection in treated wastewater improves its properties. The kinetics of disinfectant decay could be impacted by changes in treated wastewater properties. This paper studies the effect of various NB injections on the residual chlorine decay of secondary treated wastewater (STWW). It also outlines the empirical equations that were developed to represent these impacts. The results show that each type of NBs in treated wastewater had a distinct initial chlorine concentration. The outcomes demonstrated a clear impact on the decrease of the needed chlorine quantity and the reduction of chlorine decay rate when utilizing NB injection for the STWW. As a result, the residual chlorine will remain for a longer time and will resist any microbiological growth under the application of NBs on treated wastewater. Moreover, NBs in secondary treated effluent reduce chlorine usage, lowering wastewater disinfection costs.

Potential effects of aerosol generation and transmission during bedside endoscope cleaning.

Airborne transmission is among the most frequent types of nosocomial infection. Recent years have witnessed frequent outbreaks of airborne diseases, such as severe acute respiratory syndrome (SARS) in 2002, Middle East respiratory syndrome (MERS) in 2012, and coronavirus disease 2019 (COVID-19), with the latter being on the rampage since the end of 2019 and bringing the effect of aerosols on health back to the fore (Gralton et al., 2011; Wang et al., 2021). An increasing number of studies have shown that certain highly transmissible pathogens can maintain long-term stability and efficiently spread through aerosols (Leung, 2021; Lv et al., 2021). As reported previously, influenza viruses that can spread efficiently through aerosols remain stable for a longer period compared to those that cannot. The World Health Organization (WHO) has stated that aerosol-generating procedures (AGPs) play an important role in aerosol transmission in hospitals (Calderwood et al., 2021). AGPs, referring to medical procedures that produce aerosols, including dental procedures, endotracheal intubation, sputum aspiration, and laparoscopic surgeries, have been reported to be significantly associated with an increased risk of nosocomial infection among medical personnel (Hamilton, 2021).

Laser Ablation for the Synthesis of Cu/Cu2O/CuO and Its Development as Photocatalytic Material for Escherichia coli Detoxification.

Advanced Oxidation Processes (AOPs) offer promising methods for disinfection by generating radical species like hydroxyl radicals, superoxide anion radicals, and hydroxy peroxyl, which can induce oxidative stress and deactivate bacterial cells. Photocatalysis, a subset of AOPs, activates a semiconductor using specific electromagnetic wavelengths. A novel material, Cu/Cu2O/CuO nanoparticles (NPs), was synthesized via a laser ablation protocol (using a 1064 nm wavelength laser with water as a solvent, with energy ranges of 25, 50, and 80 mJ for 10 min). The target was sintered from 100 °C to 800 °C at rates of 1.6, 1.1, and 1 °C/min. The composite phases of Cu, CuO, and Cu2O showed enhanced photocatalytic activity under visible-light excitation at 368 nm. The size of Cu/Cu2O/CuO NPs facilitates penetration into microorganisms, thereby improving the disinfection effect. This study contributes to synthesizing mixed copper oxides and exploring their activation as photocatalysts for cleaner surfaces. The electronic and electrochemical properties have potential applications in other fields, such as capacitor materials. The laser ablation method allowed for modification of the band gap absorption and enhancement of the catalytic properties in Cu/Cu2O/CuO NPs compared to precursors. The disinfection of E. coli with Cu/Cu2O/CuO systems serves as a case study demonstrating the methodology's versatility for various applications, including disinfection against different microorganisms, both Gram-positive and Gram-negative.

[Evaluation of disinfection effect of high-energy pulse ultraviolet disinfection equipment in medical institution settings].

Objective: To evaluate the disinfection effect of high-energy pulse ultraviolet disinfection equipment in medical institution settings. Methods: The disinfection effect was evaluated through field tests and laboratory tests. Among them, 135 high-frequency contact points were selected from nine departments in the field test. Samples were collected before and after disinfection, and the disinfection effects of 75% alcohol wipes wiping disinfection, high-energy pulse ultraviolet disinfection robot disinfection and high-energy pulse ultraviolet handheld disinfection instrument were compared. In the laboratory test, 30 infected areas of the simulated test table were exposed to vertical ultraviolet irradiation and the bacterial-killing rate before and after disinfection was calculated. Results: In the field test, the bacteria-killing rates of 75% alcohol wipes, high-energy pulse ultraviolet disinfection robot and high-energy pulse ultraviolet handheld disinfection instrument were 94.99%, 91.53% and 95.94%, respectively, and the difference was statistically significant. The disinfection effect of the high-energy pulse ultraviolet handheld disinfection instrument was better than that of the high-energy pulse ultraviolet disinfection robot (P values <0.05). In the laboratory test, the killing log value of Staphylococcus aureus and Escherichia coli on the carrier were both greater than 3.00. In the simulated field test, the killing log value of Staphylococcus aureus on the surface samples were 4.99. Conclusion: Both the high-energy pulse ultraviolet handheld disinfection instrument and the high-energy pulse ultraviolet disinfection robot have good disinfection effects, which are similar to the disinfection effects of conventional 75% alcohol wipes.

Estimation of the UV susceptibility of aerosolized SARS-CoV-2 to 254 nm irradiation using CFD-based room disinfection simulations.

The recent COVID-19 pandemic has raised interest in efficient air disinfection solutions. The application of germicidal ultraviolet (GUV) irradiation is an excellent contender to prevent airborne transmission of COVID-19, as well as other existing and future infectious airborne diseases. While GUV has already been proven effective in inactivating SARS-CoV-2, quantitative data on UV susceptibility and dose requirements, needed to predict and optimize the performance of GUV solutions, is still limited. In this study, the UV susceptibility of aerosolized SARS-CoV-2 to 254 nm ultraviolet (UV) irradiation is investigated. This is done by employing 3D computational fluid dynamics based simulations of SARS-CoV-2 inactivation in a test chamber equipped with an upper-room UV-C luminaire and comparing the results to previously published measurements performed in the same test chamber. The UV susceptibility found in this study is (0.6 ± 0.2) m2/J, which is equivalent to a D90 dose between 3 and 6 J/m2. These values are in the same range as previous estimations based on other corona viruses and inactivation data reported in literature.

The antimicrobial activity of an antiseptic soap against Candida Albicans and Streptococcus Mutans single and dual-species biofilms on denture base and reline acrylic resins.

To evaluate the effect of antiseptic soap on single and dual-species biofilms of Candida albicans and Streptococcus mutans on denture base and reline resins. Samples of the resins were distributed into groups (n = 9) according to the prevention or disinfection protocols. In the prevention protocol, samples were immersed in the solutions (Lifebuoy, 0.5% sodium hypochlorite solution and PBS) for 7, 14 and 28 days before the single and dual-species biofilms formation. Overnight denture disinfection was simulated. In the disinfection protocol, samples were immersed in the same solutions during 8 hours after the single and dual-species biofilms formation. Antimicrobial activity was analyzed by counting colony-forming units (CFU/mL) and evaluating cell metabolism. Cell viability and protein components of the biofilm matrix were evaluated using confocal laser scanning microscopy (CLSM). Data were submitted to ANOVA, followed by Tukey's post-test (α = 0.05) or Dunnett's T3 multiple comparisons test. In the prevention protocol, Lifebuoy solution effectively reduced the number of CFU/mL of both species. In addition, the solution decreased the cell metabolism of the microorganisms. Regarding disinfection protocol, the Lifebuoy solution was able of reduce approximately of 2-3 logs for all the biofilms on the denture base and reline resin. Cellular metabolism was also reduced. The images obtained with CLSM corroborate these results. Lifebuoy solution was effective in reducing single and dual-species biofilms on denture base and reline resins.

[Design and Development of a Heat Sealing System for Rapid Reuse of Ultrasonic Probes]. / è¶ å£°æŽ¢å¤´å¿«é€Ÿå¤ç”¨çƒ­å°ç³»ç»Ÿçš„è®¾è®¡ä¸Žç ”å‘.

Objective: Ultrasound diagnosis and treatment is easy to perform and takes little time. It is widely used in clinical practice thanks to its non-invasive, real-time, and dynamic characteristics. In the process of ultrasound diagnosis and treatment, the probe may come into contact with the skin, the mucous membranes, and even the sterile parts of the body. However, it is difficult to achieve effective real-time disinfection of the probes after use and the probes are often reused, leading to the possibility of the probes carrying multiple pathogenic bacteria. At present, the processing methods for probes at home and abroad mainly include probe cleaning, probe disinfection, and physical isolation (using probe covers or sheaths). Yet, each approach has its limitations and cannot completely prevent probe contamination and infections caused by ultrasound diagnosis and treatment. For example, when condoms are used as the probe sheath, the rate of condom breakage is relatively high. The cutting and fixing of cling film or freezer bags involves complicated procedures and is difficult to perform. Disposable plastic gloves are prone to falling off and causing contamination and are hence not in compliance with the principles of sterility. Furthermore, the imaging effect of disposable plastic gloves is poor. Therefore, there is an urgent need to explore new materials to make probe covers that can not only wrap tightly around the ultrasound probe, but also help achieve effective protection and rapid reuse. Based on the concept of physical barriers, we developed in this study a heat sealing system for the rapid reuse of ultrasound probes. The system uses a heat sealing device to shrink the protective film so that it wraps tightly against the surface of the ultrasound probe, allowing for the rapid reuse of the probe while reducing the risk of nosocomial infections. The purpose of this study is to design a heat sealing system for the rapid reuse of ultrasound probes and to verify its application effect on the rapid reuse of ultrasound probes. Methods: 1) The heat sealing system for the rapid reuse of ultrasound probes was designed and tested by integrating medical and engineering methods. The system included a protective film (a multilayer co-extruded polyolefin thermal shrinkable film) and a heat sealing device, which included heating wire components, a blower, a photoelectric switch, temperature sensors, a control and drive circuit board, etc. According to the principle of thermal shrinkage, the ultrasound probe equipped with thermal shrinkable film was rapidly heated and the film would wrap closely around the ultrasound probe placed on the top of the heat sealing machine. The ultrasound probe was ready for use after the thermal shrinkage process finished. Temperature sensors were installed on the surface of the probe to test the thermal insulation performance of the system. The operation procedures of the system are as follows: placing the ultrasound probe covered with the protective film in a certain space above the protective air vent, which is detected by the photoelectric switch; the heating device heats the thermal shrinkable film with a constant flow of hot air at a set temperature value. Then, the probe is rotated so that the thermal shrinkable film will quickly wrap around the ultrasound probe. After the heat shrinking is completed, the probe can be used directly. 2) Using the convenience sampling method, 90 patients from the Department of Anesthesiology and Perioperative Medicine, the First Affiliated Hospital of Xi'an Jiaotong University were included as the research subjects. All patients were going to undergo arterial puncture under ultrasound guidance. The subjects were divided into 3 groups, with 30 patients in each group. Three measures commonly applied in clinical practice were used to process the probes in the three groups and water-soluble fluorescent labeling was applied around the puncture site before use. In the experimental group, the probes were processed with the heat sealing system. The standard operating procedures of the heat sealing system for rapid reuse of ultrasonic probes were performed to cover the ultrasonic probe and form a physical barrier to prevent probe contamination. There were two control groups. In control group 1, disinfection wipes containing double-chain quaternary ammonium salt were used to repeatedly wipe the surface of the probe for 10-15 times, and then the probe was ready for use once it dried up. In the control group 2, a disposable protective sheath was used to cover the front end of the probe and the handle end of the sheath was tied up with threads. Comparison of the water-soluble fluorescent labeling on the surface of the probe (which reflected the colony residues on the surface of the probe) before and after use and the reuse time (i.e., the lapse of time from the end of the first use to the beginning of the second use) were made between the experimental group and the two control groups. Results: 1) The temperature inside the ultrasound probe was below 40 ℃ and the heat sealing system for rapid reuse did not affect the performance of the ultrasound probe. 2) The reuse time in the heat sealing system group, as represented by (median [P25, P75]), was (8.00 [7.00, 10.00]) s, which was significantly lower than those of the disinfection wipe group at (95.50 [8.00, 214.00]) s and the protective sleeve group at (25.00 [8.00, 51.00]) s, with the differences being statistically significant (P<0.05). No fluorescence residue was found on the probe in either the heat sealing system group or the protective sheath group after use. The fluorescence residue in the heat sealing system group was significantly lower than that in the disinfection wipes group, showing statistically significant differences (χ 2=45.882, P<0.05). Conclusion: The thermal shrinkable film designed and developed in this study can be cut and trimmed according to the size of the equipment. When the film is heated, it shrinks and wraps tightly around the equipment, forming a sturdy protective layer. With the heat sealing system for rapid reuse of ultrasonic probes, we have realized the semi-automatic connection between the thermal shrinkable film and the heating device, reducing the amount of time-consuming and complicated manual operation. Furthermore, the average reuse time is shortened and the system is easy to use, which contributes to improvements in the reuse and operation efficiency of ultrasound probes. The heat sealing system reduces colony residues on the surface of the probe and forms an effective physical barrier on the probe. No probes were damaged in the study. The heat sealing system for rapid reuse of ultrasonic probes can be used as a new method to process the ultrasonic probes.

Performance of high-efficiency UV-C LEDs in water disinfection: Experimental, life cycle assessment, and economic analysis of different operational scenarios.

The widespread use of low or medium pressure mercury lamps in UV-C water disinfection should consider recent advances in UV-C LED lamps that offer a more sustainable approach and avoid its main drawbacks. The type of water and the mode of operation are critical when deciding on the treatment technology to be used. Therefore, this study investigates the potential application of UV-C LED disinfection technology in terms of kinetics, environmental assessment, and economic analysis for two scenarios: the continuous disinfection of a wastewater treatment plant (WWTP), and disinfection of harvested rainwater (RWH) in a residential household that operates intermittently. Experiments are conducted using both the new UV-C LED system and the conventional mercury lamp to disinfect real wastewater. Removal of total coliforms and Escherichia coli bacteria, with concentrations of approximately 105 and 104 CFU per 100 mL has been followed to assess the performance of both types of UV-C lamps. The experimental study provides kinetic parameters that have been further used in the environmental assessment conducted from a life cycle perspective. Additionally, considering the significant role of electricity consumption, a preliminary economic analysis has been conducted. The results indicate that first-order kinetic constants of pathogens removal with UV-C LEDs achieve 1.4 times higher values than Hg lamp. Regarding the environmental and economic assessment, for disinfection systems operating continuously, LEDs result in environmental impacts 5 times higher than Hg lamp in most categories, indicating that Hg lamps offer a viable option both from economic and environmental point of view. However, for installations with intermittent operation, LEDs emerge as the most competitive alternative, due to their ability to be turned on and off without affecting their lifespan. This study shows that UV-C LED lamps hold promise to replace conventional mercury lamps in a near future.

Assessment of chlorine and hydrogen peroxide on airborne bacteria: Disinfection efficiency and induction of antibiotic resistance.

Airborne pathogens severely threaten public health worldwide. Air disinfection is essential to ensure public health. However, excessive use of disinfectants may endanger environmental and ecological security due to the residual disinfectants and their by-products. This study systematically evaluated disinfection efficiency, induction of multidrug resistance, and the underlying mechanisms of disinfectants (NaClO and H2O2) on airborne bacteria. The results showed that airborne bacteria were effectively inactivated by atomized NaClO (>160 µg/L) and H2O2 (>320 µg/L) after 15 min. However, some bacteria still survived after disinfection by atomized NaClO (0-80 µg/L) and H2O2 (0-160 µg/L), and they exhibited significant increases in antibiotic resistance. The whole-genome sequencing of the resistant bacteria revealed distinct mutations that were responsible for both antibiotic resistance and virulence. This study also provided evidences and insights into possible mechanisms underlying the induction of antibiotic resistance by air disinfection, which involved intracellular reactive oxygen species formation, oxidative stress responses, alterations in bacterial membranes, activation of efflux pumps, and the thickening of biofilms. The present results also shed light on the role of air disinfection in inducing antibiotic resistance, which could be a crucial factor contributing to the global spread of antibiotic resistance through the air.

Resource sustainability and challenges in the supply chain: implications for infection prevention.

PURPOSE OF REVIEW: Infection prevention and control practices remain the bedrock of healthcare associated infection prevention and outbreak and epidemic control efforts. However, issues in supply chain management can hinder these efforts, as exemplified by various public health emergencies. This review explores the key role of supply chains in infection prevention and explores specific challenges. RECENT FINDINGS: In all of the critical components of infection prevention and control - hand hygiene, personal protective equipment, sterile supplies, environmental disinfection, and waste management - disruptions in supply chains have led to limited availability and dissemination. SUMMARY: Strategies to mitigate these resource constraints in the inter-epidemic period will also be highlighted. The infection prevention workforce is well poised to inform supply chain dynamics. Without robust and adequate supply chains, infection prevention and control efforts suffer which perpetuates healthcare-associated infections, clusters, and epidemics.

Nosocomial outbreak caused by disinfectant-resistant Serratia marcescens in an adult intensive care unit, Hungary, February to March 2022.

In 2022, an outbreak with severe bloodstream infections caused by Serratia marcescens occurred in an adult intensive care unit (ICU) in Hungary. Eight cases, five of whom died, were detected. Initial control measures could not stop the outbreak. We conducted a matched case-control study. In univariable analysis, the cases were more likely to be located around one sink in the ICU and had more medical procedures and medications than the controls, however, the multivariable analysis was not conclusive. Isolates from blood cultures of the cases and the ICU environment were closely related by whole genome sequencing and resistant or tolerant against the quaternary ammonium compound surface disinfectant used in the ICU. Thus, S. marcescens was able to survive in the environment despite regular cleaning and disinfection. The hospital replaced the disinfectant with another one, tightened the cleaning protocol and strengthened hand hygiene compliance among the healthcare workers. Together, these control measures have proved effective to prevent new cases. Our results highlight the importance of multidisciplinary outbreak investigations, including environmental sampling, molecular typing and testing for disinfectant resistance.

Disinfection of sink drains to reduce a source of three opportunistic pathogens, during Serratia marcescens clusters in a neonatal intensive care unit.

OBJECTIVE: Evaluate the effects of five disinfection methods on bacterial concentrations in hospital sink drains, focusing on three opportunistic pathogens (OPs): Serratia marcescens, Pseudomonas aeruginosa and Stenotrophomonas maltophilia. DESIGN: Over two years, three sampling campaigns were conducted in a neonatal intensive care unit (NICU). Samples from 19 sink drains were taken at three time points: before, during, and after disinfection. Bacterial concentration was measured using culture-based and flow cytometry methods. High-throughput short sequence typing was performed to identify the three OPs and assess S. marcescens persistence after disinfection at the genotypic level. SETTING: This study was conducted in a pediatric hospitals NICU in Montréal, Canada, which is divided in an intensive and intermediate care side, with individual rooms equipped with a sink. INTERVENTIONS: Five treatments were compared: self-disinfecting drains, chlorine disinfection, boiling water disinfection, hot tap water flushing, and steam disinfection. RESULTS: This study highlights significant differences in the effectiveness of disinfection methods. Chlorine treatment proved ineffective in reducing bacterial concentration, including the three OPs. In contrast, all other drain interventions resulted in an immediate reduction in culturable bacteria (4-8 log) and intact cells (2-3 log). Thermal methods, particularly boiling water and steam treatments, exhibited superior effectiveness in reducing bacterial loads, including OPs. However, in drains with well-established bacterial biofilms, clonal strains of S. marcescens recolonized the drains after heat treatments. CONCLUSIONS: Our study supports thermal disinfection (>80°C) for pathogen reduction in drains but highlights the need for additional trials and the implementation of specific measures to limit biofilm formation.

Disinfection by-product formation potential in response to variability in dissolved organic matter and nutrient inputs: Insights from a mesocosm study.

Changes in rainfall patterns driven by climate change affect the transport of dissolved organic matter (DOM) and nutrients through runoff to freshwater systems. This presents challenges for drinking water providers. DOM, which is a heterogeneous mix of organic molecules, serves as a critical precursor for disinfection by-products (DBPs) which are associated with adverse health effects. Predicting DBP formation is complex due to changes in DOM concentration and composition in source waters, intensified by altered rainfall frequency and intensity. We employed a novel mesocosm approach to investigate the response of DBP precursors to variability in DOM composition and inorganic nutrients, such as nitrogen and phosphorus, export to lakes. Three distinct pulse event scenarios, mimicking extreme, intermittent, and continuous runoff were studied. Simultaneous experiments were conducted at two boreal lakes with distinct DOM composition, as reflected in their color (brown and clear lakes), and bromide content, using standardized methods. Results showed primarily site-specific changes in DBP precursors, some heavily influenced by runoff variability. Intermittent and daily pulse events in the clear-water mesocosms exhibited higher haloacetonitriles (HANs) formation potential linked to freshly produced protein-like DOM enhanced by light availability. In contrast, trihalomethanes (THMs), associated with humic-like DOM, showed no significant differences between pulse events in the brown-water mesocosms. Elevated bromide concentration in the clear mesocosms critically influenced THMs speciation and concentrations. These findings contribute to understanding how changing precipitation patterns impact the dynamics of DBP formation, thereby offering insights for monitoring the mobilization and alterations of DBP precursors within catchment areas and lake ecosystems.

Study on the disinfection effect of chlorine dioxide disinfectant (ClO2) on dental unit waterlines and its in vitro safety evaluation.

BACKGROUND: Ensuring the safety of dental unit waterlines (DUWLs) has become a pivotal issue in dental care practices, focusing on the health implications for both patients and healthcare providers. The inherent structure and usage conditions of DUWLs contribute to the risk of biofilm formation and bacterial growth, highlighting the need for effective disinfection solutions.The quest for a disinfection method that is both safe for clinical use and effective against pathogens such as Staphylococcus aureus and Escherichia coli in DUWLs underscores the urgency of this research. MATERIALS: Chlorine dioxide disinfectants at concentrations of 5, 20, and 80 mg/L were used to treat biofilms of S. aureus and E. coli cultured in DUWLs. The disinfection effectiveness was assessed through bacterial counts and culturing. Simultaneously, human skin fibroblast cells were treated with the disinfectant to observe changes in cell morphology and cytotoxicity. Additionally, the study included corrosion tests on various metals (carbon steel, brass, stainless steel, aluminum, etc.). RESULTS: Experimental results showed that chlorine dioxide disinfectants at concentrations of 20 mg/L and 80 mg/L significantly reduced the bacterial count of S. aureus and E. coli, indicating effective disinfection. In terms of cytotoxicity, higher concentrations were more harmful to cellular safety, but even at 80 mg/L, the cytotoxicity of chlorine dioxide remained within controllable limits. Corrosion tests revealed that chlorine dioxide disinfectants had a certain corrosive effect on carbon steel and brass, and the degree of corrosion increased with the concentration of the disinfectant. CONCLUSION: After thorough research, we recommend using chlorine dioxide disinfectant at a concentration of 20 mg/L for significantly reducing bacterial biofilms in dental unit waterlines (DUWLs). This concentration also ensures satisfactory cell safety and metal corrosion resistance.

Insertion site and risk of peripheral intravenous catheter colonization and/or local infection: a post hoc analysis of the CLEAN 3 study including more than 800 catheters.

AIM: Although uncommon, infections associated with peripheral intravenous catheters (PIVCs) may be responsible for severe life-threatening complications and increase healthcare costs. Few data are available on the relationship between PIVC insertion site and risk of infectious complications. METHODS: We performed a post hoc analysis of the CLEAN 3 database, a randomized 2 × 2 factorial study comparing two skin disinfection procedures (2% chlorhexidine-alcohol or 5% povidone iodine-alcohol) and two types of medical devices (innovative or standard) in 989 adults patients requiring PIVC insertion before admission to a medical ward. Insertion sites were grouped into five areas: hand, wrist, forearm, cubital fossa and upper arm. We evaluated the risk of risk of PIVC colonization (i.e., tip culture eluate in broth showing at least one microorganism in a concentration of at least 1000 Colony Forming Units per mL) and/or local infection (i.e., organisms growing from purulent discharge at PIVC insertion site with no evidence of associated bloodstream infection), and the risk of positive PIVC tip culture (i.e., PIVC-tip culture eluate in broth showing at least one microorganism regardless of its amount) using multivariate Cox models. RESULTS: Eight hundred twenty three PIVCs with known insertion site and sent to the laboratory for quantitative culture were included. After adjustment for confounding factors, PIVC insertion at the cubital fossa or wrist was associated with increased risk of PIVC colonization and/or local infection (HR [95% CI], 1.64 [0.92-2.93] and 2.11 [1.08-4.13]) and of positive PIVC tip culture (HR [95% CI], 1.49 [1.02-2.18] and 1.59 [0.98-2.59]). CONCLUSION: PIVC insertion at the wrist or cubital fossa should be avoided whenever possible to reduce the risk of catheter colonization and/or local infection and of positive PIVC tip culture.

An effective and rapidly degradable disinfectant from disinfection byproducts.

Chloroxylenol is a worldwide commonly used disinfectant. The massive consumption and relatively high chemical stability of chloroxylenol have caused eco-toxicological threats in receiving waters. We noticed that chloroxylenol has a chemical structure similar to numerous halo-phenolic disinfection byproducts. Solar detoxification of some halo-phenolic disinfection byproducts intrigued us to select a rapidly degradable chloroxylenol alternative from them. In investigating antimicrobial activities of disinfection byproducts, we found that 2,6-dichlorobenzoquinone was 9.0-22 times more efficient than chloroxylenol in inactivating the tested bacteria, fungi and viruses. Also, the developmental toxicity of 2,6-dichlorobenzoquinone to marine polychaete embryos decreased rapidly due to its rapid degradation via hydrolysis in receiving seawater, even without sunlight. Our work shows that 2,6-dichlorobenzoquinone is a promising disinfectant that well addresses human biosecurity and environmental sustainability. More importantly, our work may enlighten scientists to exploit the slightly alkaline nature of seawater and develop other industrial products that can degrade rapidly via hydrolysis in seawater.