Objective To investigate the disinfection eff icacy of 300 g/L hydrogen peroxide at different dosages and under various environmental humidity conditions on the chamber and the rear side of the exhaust high-eff iciency f ilter of type A2 biosafety cabinets, and to determine the optimal application conditions. Methods Geobacillus stearothermophilus spore strips and hydrogen peroxide color-change indicator cards were placed at 8 corners of the cabinet’s operating chamber and 5 points on the rear side of the exhaust high-eff iciency f ilter. After sealing, the cabinet was connected to an MZ-V200 vaporized hydrogen peroxide generator. Four dosage gradients (80, 100, 120, 140 mL) and six initial relative humidity gradients (50.0％ - 99.9％) were set. Disinfection eff icacy was assessed by spore strip culture combined with indicator card color change. Results At a dosage of 120 mL and environmental relative humidity ≤70％, a 65 min vaporization cycle disinfection completely inactivated indicator microorganisms inside the cabinet and on the rear side of the f ilter, with a 100％ pass rate. When humidity exceeded 70％, the number of positive spore strips on the rear side of the f ilter increased progressively, and the pass rate dropped to 66.7％. In the low-dosage groups (80, 100 mL), only chamber disinfection was qualif ied, while the qualif ication rates on the rear side of the f ilter were 79.5％ and 84.6％, respectively. Conclusion Hydrogen peroxide dosage and environmental humidity are key factors for disinfection. High humidity impedes disinfectant penetration through the f ilter. The optimal conditions are a dosage of 120 mL and environmental relative humidity of ≤70％.
Objective To evaluate the antibacterial and bactericidal effects of two types of Allium Sativum juice against common enteric pathogenic bacteria, and to provide a scientif ic basis for its application in household food hygiene protection. Methods The disc diffusion method was used to determine the inhibition zone diameters of Allium Sativum juice against f ive species of enteric pathogenic bacteria, and the results were compared with those of 12 f irstline antibacterial agents. The pour plate method was used to determine the bactericidal rates of different concentrations of Allium Sativum juice under simulated catering conditions (25℃, 30 min). Results Allium Sativum juice showed antibacterial activity against all f ive enteric pathogenic bacteria. At concentrations ≥10％, the Allium Sativum juices from two types of garlic exhibited bactericidal rates >75％ against all tested bacteria; among them, 10％ multiclove Allium Sativum juice achieved a 100％ bactericidal rate. When the concentration was <10％, the eff icacy decreased, but Vibrio parahaemolyticus was highly sensitive to both types of Allium Sativum juice, with a bactericidal rate still >95％ at 1.25％ Allium Sativum juice. Conclusion Allium Sativum juice exhibits a broad-spectrum antibacterial effect. The concentration of ≥10％ Allium Sativum juice can effectively kill bacteria, while the concentration of ≥1.25％ Allium Sativum juice can reduce the risk of Vibrio parahaemolyticus infection.
Objective To compare the difference in the number of microbial colonies cultivated by pour plate method and spread plate method to provide a reference for the selection of microbial quantitative culture methods. Methods The pour plate method and the spread plate method were used to observe the growth of the cultured microbial colonies, and the effects of the two inoculation methods on the counting of viable bacteria were compared. Results When the inoculation amount of Staphylococcus aureus, Escherichia coli, and Candida albicans was 0.1 mL or 0.5 mL, as well as when the inoculation amount of Staphylococcus aureus and Candida albicans was 1.0 mL, there was no significant difference in the number of colonies inoculated by pour plate method and spread plate method (P>0.05). When the inoculation amount was 2.0 mL, the spread plate method could not count the colonies. When the inoculation amount of Escherichia coli was ≥1.0 mL, the spread plate method could not count the colonies. The obvious colonies could be formed after 24 h of S. aureus culture and 36 h of C. albicans culture by spread plate method, while the colonies were small in the same time by pour plate method. Conclusion In the counting culture of viable bacteria, the spread plate method cannot replace the pour plate method. In emergency monitoring scenarios, the spread plate method can provide a rapid preliminary assessment of microbial content and also facilitates the isolation and identification of pathogenic bacteria.
Objective To evaluate the microbial contamination status of dental units waterlines in medical institutions, and to provide a scientif ic basis for the development and implementation of targeted intervention measures. Methods Six medical institutions of different levels in Nanjing were selected, and metagenomic analysis was performed on the dominant bacteria in 17 water samples from three-way syringes of dental units, including metagenomic sequencing and β-diversity analysis. Results At the phylum level, Pseudomonadota was the dominant bacterial phylum in all DUWL samples. At the genus level, Methylibium was the dominant genus in DUWL of the 2 tertiary medical institutions, while Bradyrhizobium was the dominant genus in DUWL of 2 secondary medical institutions and the 2 ungraded dental clinics. Statistically signif icant differences were observed in the composition of microbial communities among the three groups of samples (P=0.001). Conclusion Microbial contamination is prevalent in DUWL of the surveyed medical institutions, and there are differences in the composition of microbial communities. Targeted prevention and control measures for DUWL contamination should be developed based on the dominant bacteria.
Objective To study the killing effect of pulsed ultraviolet rays at different irradiation doses on bacteria and to evaluate the effect of high-energy pulsed ultraviolet disinfection equipment for surface disinfection in intensive care units. Methods Through simulated on-site and on-site disinfection tests, the killing effects of three disinfection methods including high-energy pulsed ultraviolet handheld disinfection instrument, high-energy pulsed ultraviolet disinfection robot, and 75％ alcohol wipes-on natural bacteria and indicator bacteria (Staphylococcus aureus, Escherichia coli) were compared to evaluate the disinfection effect of the high-energy pulsed ultraviolet disinfection equipment in the intensive care unit. Results On-site disinfection tests showed that irradiating object surfaces with the high-energy pulsed ultraviolet handheld disinfection instrument for 15 s, the killing rate of natural bacteria was 98.0％. When irradiating object surfaces with the high-energy pulsed ultraviolet disinfection robot for 10 min, the bacterial killing rate was 97.3％. Wiping the surface with 75％ alcohol wipes for 60 s achieved a natural bacterial kill rate of 99.5％. The simulated disinfection test showed that after 15 s of irradiation with the high-energy pulsed ultraviolet handheld disinfection instrument, the log reduction values for Staphylococcus aureus and Escherichia coli were both >3.0. After 10 min of irradiation with the high-energy pulsed ultraviolet disinfection robot, the log reduction values for Staphylococcus aureus and Escherichia coli were 1.02 and 3.56, respectively. After wiping disinfection with 75％ alcohol wipes for 60 s, the log reduction values for both bacteria were less than 3.0. Conclusion The high-energy pulsed ultraviolet disinfection equipment has demonstrated favorable disinfection efficacy in the intensive care unit.
Objective To study the applicability of slightly acidic electrolyzed water to disinfect dental instruments and to provide evidence for practical clinical application. Methods The used dental diagnosis and treatment equipment were selected as test objects and were divided into three categories according to the degree of risk: high, medium and low risk equipment. The control group contained a total of 54 instruments of three types, which were soaked and decontaminated only with multi-enzyme cleaning solution; the test group was divided into 3 subgroups according to the disinfection time of 2.5, 5.0, and 10 min. Each subgroup contained 30 instruments of three types, a total of 270 pieces. After multi-enzyme cleaning and decontamination, they were soaked and disinfected in slightly acidic electrolytic water containing available chlorine 43-48 mg/L. The disinfection effect of slightly acidic electrolyzed water under different action times was evaluated through cotton swab smear sampling and quantitative bacterial detection. Results The cleaned dental diagnosis and treatment instruments were soaked for 10 min with slightly acidic electrolyzed water. No living bacteria were detected in any of the three types of dangerous instruments after disinfection. Conclusion Slightly acidic electrolyzed water has good disinfection effect on dental instruments.
Objective To understand the current status of disinfection quality and management in kindergartens in Sichuan Province, so as to identify weaknesses and propose targeted suggestions. Methods Questionnaire surveys, on-site sampling, and detection methods were used to investigate the disinfection quality and management of 58 kindergartens. Results A total of 775 disinfection staff were equipped in the investigated kindergartens, including 69 full-time staff (8.90％). The educational background of disinfection staff was mainly senior high school education or below (62.58％), and 1-5 years of work experience (68.52％). 22.41％ institutions conducted ultraviolet lamp irradiance monitoring and 18.97％ institutions performed disinfection efficacy evaluations, respectively. The hand hygiene facilities provided were mainly hand-operated faucets (89.66％). The main method of handwashing was running water and soap (68.97％). The drying method was mainly using individual towels (89.66％). A total of 4 912 object surfaces were sampled, with an overall qualified rate of 89.33％, and the faucet had the lowest qualified rate (69.85％). A total of 1 018 staff hand hygiene samples were collected, with an overall qualified rate of 68.17％, and child-care workers had the lowest qualified rate (61.47％). Conclusion There are weaknesses in disinfection work in kindergartens in Sichuan Province; the qualified rate of hygiene and disinfection quality is relatively low. It is necessary to further increase the number of full-time disinfection personnel and strengthen supervision over disinfection work, so as to improve the disinfection management level of kindergartens.
Objective To understand the current status of cleaning and disinfection management of medical textiles in medical institutions, so as to provide a basis for strengthening the hygienic management. Methods In accordance with WS/T 508—2016 Technical Specification for Washing and Disinfection of Medical Textiles in Hospitals, a questionnaire survey was conducted on the management, cleaning and disinfection of medical textiles in medical institutions across 13 cities of Guangdong Province. Results Among the 73 surveyed medical institutions, 64.4％ of them entrusted socialized washing service institutions with the cleaning and disinfection of medical textiles. A total of 84.9％ of the institutions had established a full-process management system for medical textiles. Only 20.5％ of the institutions used water-soluble textile bags to contain infectious textiles. 50.0％ of the institutions adopted hot washing methods, and 42.3％ were equipped with hygienic isolated washing equipment. A small number of medical institutions failed to adopt special-machine washing for neonatal textiles (11.5％) as well as operating room and infectious textiles (3.8％). Besides, 30.8％ of the institutions did not realize centralized cleaning and disinfection of cloth towels and floor cloths. Conclusion The overall status of cleaning and disinfection of medical textiles in medical institutions of Guangdong Province is favorable, but continuous supervision still needs to be strengthened.
Objective To understand the microbial pollution status of funeral places in Gansu Province, and to provide a basis for formulating targeted prevention and control strategies. Methods Three funeral sites in Gansu Province were selected for on-site sampling and bacteriological analysis on the surfaces of easily contaminated objects and staff hands. Three surface samples and three hand samples were randomly selected for metagenomic sequencing to analyze the main categories and abundance of contaminating bacteria. Results A total of 88 surface samples and 31 staff hand samples were collected. The bacterial test showed that 15.9％ of the object surfaces had a total bacterial count of ≥ 15 cfu/cm2, and 83.9％ of the staff had a total bacterial count of ≥10 cfu/cm2 on their hands. Even after implementing hand hygiene, 80.7％ of the staff still had a bacterial count of ≥10 cfu/cm2. The detection rate of pathogenic or opportunistic pathogens on the surface of objects was 53.8％. The top five species in terms of composition ratio were Geobacillus, Staphylococcus epidermidis, Bacillus megaterium, Staphylococcus hominis, and Bacillus licheniformis. The detection rate of pathogenic bacteria or opportunistic pathogens on the hands of staff members was 57.1％. The top five species in terms of composition ratio were Staphylococcus epidermidis, Staphylococcus hominis, Staphylococcus haemolyticus, Oslo Moraxella and Salmonella. Pathogenic Salmonella was detected on both surface surfaces of funeral facilities and on staff hand samples, while pathogenic Staphylococcus aureus was also identified in staff hand samples. The data from six metagenomic sequencing samples further indicated that there were varying degrees of contamination by opportunistic and pathogenic bacteria on the surfaces of objects in funeral facilities and on staff hands. Conclusion In Gansu Province, the surface of funeral objects and the hands of staff are heavily contaminated, and hand hygiene has no signif icant effect on the reduction of bacteria in the hands of funeral places workers in Gansu Province. The relevant funeral management departments in Gansu Province should strengthen the guidance and supervision of disinfection management of funeral places.
Objective To construct a risk prediction model for central line-associated bloodstream infection (CLABSI) in hospitalized cancer patients, and to provide a precise assessment tool for early detection of related infection risks. Methods Clinical data of hospitalized cancer patients were collected through literature review and investigation. logistic regression analysis was used to evaluate 26 characteristics and to develop a CLABSI risk prediction model. Results A total of 1 683 hospitalized cancer patients were included. logistic regression analysis showed that albumin level, number of puncture attempts during catheter insertion, use of glucocorticoids, use of antibiotics, dressing change frequency, history of catheter-related infection, catheter-associated thrombosis, and tumor type were independent risk factors for CLABSI in hospitalized cancer patients. The optimal classif ication threshold was determined to be 0.029. Validation in the test set showed that the model achieved an AUC value of 0.933 on the ROC curve, with a sensitivity of 0.957, a specif icity of 0.882, and a balanced accuracy of 0.920. Conclusion The nomogram model established in this study demonstrates strong predictive performance and holds clinical application value.
Objective To understand the performance parameters of biosafety cabinets in Wenzhou and the disinfection effect of the workbench, and to provide a reference for reducing the risk of infection during the experiment. Methods According to YY 0569—2011 Standard for Class Ⅱ Biosafety Cabinets, instrumental testing and ATP bioluminescence method were used to conduct monitoring on the safety performance indicators and workbench cleanliness of class Ⅱ biosafety cabinets within the jurisdiction. Results The qualif ied rate of 178 class Ⅱ biosafety cabinets from different types of institutions in Wenzhou was 88.76％, and that of those in disease prevention and control institutions, medical and health institutions, and third-party testing agency was 95.14％, 91.38％, and 41.17％ respectively. The qualif ied rates of cleanliness, average vertical airf low velocity, average airf low velocity at the working window, noise, ultraviolet lamp irradiance, and airf low direction of the tested biosafety cabinets were 90.45％, 94.94％, 87.64％, 82.02％, 91.57％, and 96.62％ respectively. After work, wiping the workbench of class Ⅱ biosafety cabinets with chlorine dioxide disinfectant had the highest qualif ied rate (100.00％); the qualif ied rates of wiping disinfection after spraying disinfectant, and wiping treatment after ultraviolet irradiation+disinfectant spraying were 90.23％ and 96.65％ respectively. Conclusion The class Ⅱ biosafety cabinets in third-party testing institutions in Wenzhou have a low qualified rate, and the cleanliness of the workbenches of biosafety cabinets in various types of institutions varies significantly. It is necessary to strengthen monitoring and management and select appropriate disinfection methods.
Objective To analyze the distribution characteristics of pathogens and risk factors of nosocomial infections in hospitalized tumor patients in a tertiary hospital, so as to provide a reference for the rational clinical use of antibiotics and bundled infection control strategies. Methods A retrospective investigation was conducted to analyze the distribution of pathogens and the clinical risk factors associated with HAIs in hospitalized cancer patients. Results Among the 12 394 hospitalized cancer patients investigated, 352 cases of HAIs occurred, with an infection rate of 2.84％ per case-visit. The primary site of infection was the lower respiratory tract, accounting for 53.13％. Patient age, underlying comorbidities, and length of hospital stay were identif ied as signif icant risk factors for HAIs. A total of 385 pathogenic strains were isolated from clinical specimens; Gram-negative bacteria, Gram-positive bacteria, and fungi accounted for 70.13％, 25.71％, and 4.16％, respectively. The top three Gram-negative bacteria identif ied were Klebsiella pneumoniae, Escherichia coli, and Acinetobacter baumannii. Gram-positive bacteria were predominantly Staphylococcus aureus and Enterococcus species. Conclusion Healthcare-associated infections in patients with malignant tumors result from the interaction of multiple factors. The pathogenic spectrum is dominated by Gram-negative bacilli, with serious drug resistance observed. The incidence of infection in high-risk populations should be reduced through prospective risk assessment and precise antimicrobial stewardship.
Objective To understand the disinfection effect of medical institutions in Xuchang City, so as to analyze the weak links in nosocomial infection control. Methods From 2018 to 2024, on-site sampling and microbial testing were conducted for disinfection monitoring programs in medical institutions at different levels in the city, followed by analysis of the monitoring results. Results A total of 2 626 samples were collected over seven years, with the total qualified rate of 95.54％. The qualified rates were notably high (≥99％) from 2018 to 2020, while the rate in 2024 was lower (93.08％). The qualified rates of disinfectants in use and pressure steam sterilizers were 100％; the qualified rates of wastewater and medical water were lower, at 85.37％ and 81.08％, respectively. The qualified rates for medical water and sewage in secondary medical institutions were relatively low, at 72.63％ and 73.98％, respectively. The qualified rates for dental treatments water and surgical hand-washing water were the lowest, at 70.73％ and 72.00％, respectively. There was no statistically significant difference in the quality rates between physicians and nurses (91.98％ vs 94.07％; χ2=1.067, P= 0.302). Conclusion The disinfection work of medical institutions in Xuchang City is generally well, but there are still some problems. It is necessary to strengthen the monitoring and management of the disinfection quality of sewage and medical water.
Objective To compare the cleaning effects of decompression boiling cleaning and ultrasonic spray cleaning on glass central venous pressure (CVP) manometers, so as to provide evidence for optimization cleaning protocols. Methods A total of 600 clinically used CVP manometers were selected and randomly divided into two equal groups, which were treated with decompression boiling cleaning and ultrasonic spray cleaning respectively. Visual inspection, 75％ ethanol gauze wiping test and ATP bioluminescence detection were adopted to compare the qualif ied rates and damage rates of the two groups. The time consumption of cleaning was recorded, and the subjective fatigue scores were evaluated. Results There was no signif icant difference in the qualif ied rates of surface and lumen of manometers between the two groups by visual inspection and ATP detection (P>0.05). In the 75％ ethanol gauze wiping test, the external surface qualif ied rate of the ultrasonic spray cleaning group was higher than that of the decompression boiling cleaning group (50.52％ vs 41.20％; χ2=5.260, P=0.022). Compared with the decompression boiling cleaning group, the ultrasonic spray cleaning group presented lower damage rate (4.33％ vs 11.00％; χ2=9.418, P=0.002) and shorter average cleaning time (49.00 min vs 52.67 min; t=4.523, P=0.021), whereas the average subjective fatigue score of operators was higher (2.33 vs 1.00; t=3.464, P=0.035). Conclusion Ultrasonic spray cleaning can improve the cleaning quality of glass CVP manometers and reduce the damage rate, and can be used as the preferred cleaning protocol.
