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.
目的： 评价医疗机构场景下高能脉冲紫外线消毒设备消毒效果。 方法： 分别通过现场试验和实验室试验进行消毒效果评价。其中，现场试验选择9个科室135个高频接触点位，消毒前后采样，比较75%酒精湿巾擦拭消毒、高能脉冲紫外消毒机器人消毒和高能脉冲紫外手持消毒仪消毒效果；实验室试验将模拟试验桌面的30个染菌区块置于紫外线垂直照射下，计算消毒前后细菌杀灭率。 结果： 现场试验中75%酒精湿巾擦拭、高能脉冲紫外消毒机器人和高能脉冲紫外手持消毒仪细菌杀灭率分别为94.99%、91.53%和95.94%，差异有统计学意义，其中高能脉冲紫外手持消毒仪的消毒效果好于高能脉冲紫外消毒机器人（P<0.05）。实验室试验中高能脉冲紫外手持消毒仪对染菌载体上金黄色葡萄球菌和大肠杆菌的杀灭对数值均>3.00，模拟现场试验中高能脉冲紫外手持消毒仪对物体表面样本上金黄色葡萄球菌的杀灭对数值为4.99。 结论： 高能脉冲紫外手持消毒仪和高能脉冲紫外消毒机器人消毒效果均较好，与常规75%酒精湿巾擦拭消毒效果相近。.

UNASSIGNED: 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.
UNASSIGNED: 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.
UNASSIGNED: 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).
UNASSIGNED: 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.

The aim was to analyse the influence of an apical ledge on root canal disinfection. Forty-four single-rooted teeth were micro-CT scanned and inoculated with Enterococcus faecalis. In Group S shaping was performed with ProTaper Next (PTN) up to X3 at working length (WL). In Group L an apical ledge was created with K-Files #40 and shaping completed up to PTN X3. NaOCl 5% and EDTA 10% irrigant solutions were alternated. Confocal laser scanning microscope (CLSM) and viability staining were used to analyse the proportions of dead (red) and live (green) bacteria and penetration ability inside dentinal tubules. Data were analysed with the Mann-Whitney test with Bonferroni correction (p < 0.05). In Group L the amount of red fluorescence resulted significantly lower, and penetration ability was decreased in the apical and middle portion (p < 0.05). The presence of an apical ledge may negatively influence the disinfection both in the apical and middle third.

BACKGROUND: The mounted UV-C lamp requires no separate space or labor for transport, but data on its effectiveness for surface disinfection are scarce. We aimed to evaluate the performance of ceiling-mounted UV-C lamps.
METHODS: This study was conducted in an empty room with UV-C lamps in the biocontainment unit of a tertiary care hospital in South Korea. UV-C lamps were installed on the ceiling of the patient room, anteroom, and toilet. Each pathogen (Staphylococcus aureus, Escherichia coli, Candida krusei, Bacillus cereus, and Mycobacterium peregrinum) was inoculated on blood agar plates and placed in 20 selected places from the UV-C lamp, and irradiation was applied for 15 min. As a control group, the bacterial solution was diluted 10,000 times and UV was not applied.
RESULTS: A mean ± SD of 5.95 ± 0.91 log reduction was observed with UV irradiation compared with the control. The log reduction was greatest for S. aureus [median, 7.05 (IQR, 6.49-7.26)] and least for M. peregrinum [median, 4.88 (IQR, 4.58-5.24)]. The degree of log reduction was inversely proportional to the square of the distance from the UV-C lamp (R2 = -0.12, p < 0.001).
CONCLUSIONS: In this study, ceiling-mounted UV-C demonstrated effective disinfection of at least 4-log reduction of the test organisms within a 4-m distance. Mounted UV-C lighting is a considerable option for improving surface disinfection.

OBJECTIVE: The disinfection efficiency of disinfectants differs in specific conditions. This study aimed to investigate the disinfection efficiency of commercial hydrogen peroxide, chlorine dioxide, and chlorine disinfectant on real field surfaces and provide data for precise disinfection.
METHODS: Simulated field disinfection and field disinfection methods were conducted to quantitatively evaluate the disinfection efficiency of hydrogen peroxide, chlorine dioxide, and sodium dichloroisocyanurate. The log10 reduction of biological indicators, Escherichia coli (ATCC 8099) and Staphylococcus aureus (ATCC 6538), was calculated. Next, the reduction in natural bacteria on the surfaces of a food production and processing workshop and a biosafety laboratory was determined.
RESULTS: The 3 commercial disinfectants evaluated were effective against E coli and S aureus, with a reduction of more than 3.00 log10 colony-forming units/mL tested for an exposure time of 15 minutes with 3.5% hydrogen peroxide, 100 mg/L chlorine dioxide, and 250 mg/L sodium dichloroisocyanurate. The natural load in the food production and processing workshop decreased by more than 90% using 10.5% hydrogen peroxide with an exposure time of 30 minutes. The same disinfection level in the biosafety level 2 laboratory was achieved by 500 mg/L chlorine dioxide at an exposure time of 60 minutes and 450 mg/L sodium dichloroisocyanurate at 60 minutes.
CONCLUSIONS: This study provides a reference for precise disinfection of surfaces in the food industry and biosafety laboratories.

BACKGROUND: Central line-associated bloodstream infections (CLABSIs) are among the most epidemiologically relevant health care-associated infections. The aseptic non-touch technique (ANTT) is a standardized practice used to prevent CLABSIs. In a pediatric hospital, the overall CLABSI rate was 1.92/1000 catheter days (CD). However, in one unit, the rate was 5.7/1000 CD.
METHODS: Nurses were trained in ANTT. For the implementation, plan-do-study-act (PDSA) cycles were completed. Adherence monitoring of the ANTT and epidemiological surveillance were performed.
RESULTS: ANTT adherence of 95% was achieved after 6 PDSA cycles. Hand hygiene and general cleaning reached 100% adherence. Port disinfection and material collection had the lowest adherence rates, with 76.2% and 84.7%, respectively. The CLABSI rate decreased from 5.7 to 1.26/1000 CD.
CONCLUSIONS: The implementation of ANTT helped reduce the CLABSI rate. Training and continuous monitoring are key to maintaining ANTT adherence.
UNASSIGNED: Las infecciones relacionadas con catéteres venosos centrales son unas de las infecciones asociadas a la atención de salud con mayor relevancia epidemiológica. La técnica aséptica «no tocar» es una práctica estandarizada que se utiliza para prevenir estas infecciones. En un hospital pediátrico, la tasa de infecciones relacionadas con catéteres venosos centrales fue de 1.92/1000 días de catéter. Sin embargo, en una de las unidades la tasa fue de 5.7/1000 días de catéter.
UNASSIGNED: Se capacitaron enfermeras en la técnica aséptica «no tocar». Para la implementación se cumplieron ciclos de planificar-hacer-estudiar-actuar (PHEA). Se realizaron seguimiento de la adherencia a la técnica y vigilancia epidemiológica.
RESULTS: Se logró una adherencia a la técnica aséptica «no tocar» del 95% después de seis ciclos. La higiene de manos y la limpieza general alcanzaron un 100% de cumplimiento. La desinfección de los puertos y la recolección de material alcanzaron la menor adherencia, con un 76.2% y un 84.7%, respectivamente. La tasa de infecciones relacionadas con catéteres venosos centrales disminuyó de 5.7 a 1.26 por 1000 días de catéter.
CONCLUSIONS: La implementación de la técnica aséptica «no tocar» ayudó en la reducción de infecciones relacionadas con catéteres venosos centrales. La capacitación y el seguimiento continuo son clave para mantener el cumplimiento de la técnica.

OBJECTIVE: Evaluate the efficacy of denture cleaners on the adhesion of Candida albicans and their effects on the surface, optical, and mechanical properties of resins for conventional, milled, and 3D-printed denture bases.
METHODS: A total of 240 resin samples were made, 120 for testing Candida albicans adhesion, optical stabilities (ΔE00), roughness (Ra), hydrophilicity (°), surface free energy (Owens-Wendt) and 120 samples for testing Candida albicans adhesion, surface microhardness (Knoop), flexural strength and modulus of elasticity in a three-point test, in which they were divided into 3 groups of denture resin (n = 40) and subdivided into 5 cleaners of dentures (n = 8). Data were evaluated by two-way ANOVA and Tukey\'s test for multiple comparisons (α = 0.05).
RESULTS: Denture cleaners with an alkaline solution and dilute acid composition were those that showed the greatest effectiveness in reducing Candida albicans (P < 0.001), however 1% NaOCl significantly affected the properties of the resins (P < 0.05). Denture 3D-printed showed that the surface microhardness was significantly lower for all cleansers (P < 0.05).
CONCLUSIONS: Listerine demonstrated superior efficacy in reducing Candida albicans with minimal effect on denture properties, whereas 1% NaOCl had a significant negative impact on the properties. The mechanical properties were significantly lower in 3D-printed resin than in other resins for all denture cleansers.
CONCLUSIONS: Denture base materials are being sold to adapt to the CAD/CAM system, increasing the number of users of dentures manufactured with this system. Despite this, there is little investigation into denture cleaners regarding the adhesion capacity of microorganisms and the optical, surface and mechanical properties of dentures, thus requiring further investigation.

OBJECTIVE: Ultraviolet light in the UV-C band is known as germicidal radiation and was widely used for both sterilization of the equipment and creation of a sterile environment. The aim of the study is to assess the effectiveness of inactivation of microorganisms deposited on surfaces with various textures by UV-C radiation disinfection devices.
METHODS: Five microorganisms (3 bacteria, virus, and fungus) deposited on metal, plastic, and glass surfaces with smooth and rough textures were irradiated with UV-C light emitted by low-pressure mercury lamp and ultraviolet emitting diodes (LEDs), from a distance of 0.5 m, 1 m, and 1.5 m to check their survivability after 20-minute exposure.
CONCLUSIONS: Both tested UV-C sources were effective in inactivation of microorganisms; however, LED emitter was more efficient in this respect than the mercury lamp. The survival rate of microorganisms depended on the UV-C dose, conditioned by the distance from UV-C source being the highest at 0.5 m and the lowest at 1.5 m. For the tested microorganisms, the highest survival rate after UV-C irradiation was usually visible on glass and plastic surfaces. This observation should be considered in all environments where the type of material (from which the elements of technical equipment are manufactured and may be contaminated by specific activities) is important for maintaining the proper level of hygiene and avoiding the unwanted and uncontrolled spread of microbiological pollution.

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.

Waterborne pathogens invariably present considerable threats to public health. The quorum sensing (QS) system is instrumental in coordinating bacterial growth and metabolisms. However, the responses and regulatory mechanisms of bacteria to various disinfection technologies through quorum sensing are still unclear. This study examines the inactivation effect of chlorination and ozonation on biofilms and planktonic cells of QS signaling-deficient mutants of Pseudomonas aeruginosa. Cell counting and viability assessment revealed that the combined disinfection of chlorine and ozone was the most effective for inactivating planktonic P. aeruginosa within 10 min of exposure. Additionally, microfluidic chip culture demonstrated that the secretion of quinolone signals escalated biofilms\' disinfection resistance. Disinfection exposure significantly altered the gene expression of wild-type strains and QS signaling-deficient mutants. Moreover, the QS system triggered multilayered gene expression programs as a responsive protection to disinfectant exposure, including oxidative stress, ribosome synthesis, and the nutrient absorption of bacteria. These insights broaden our understanding of bacterial QS in response to disinfection, promising potential strategies toward efficient disinfection processes.