1.Construction of a system for isolation and purification of NK cells from whole blood donations
Tengyu CAO ; Huayu LIN ; Xuanzhi ZHANG ; Cuimi DUAN ; Yi LIU ; Xiaonan XUE ; Liping SUN ; Yang YU
Chinese Journal of Blood Transfusion 2025;38(2):181-188
[Objective] To explore the feasibility of using whole blood as a source of NK cells for allogeneic CAR NK cell therapy and activated NK cell reinfusion therapy, and initially construct a technical system for the separation and purification of NK cells from whole blood. [Methods] All peripheral blood mononuclear cells (PBMCs) were enriched from 400 mL of whole blood by manual separation and machine separation, respectively. The erythrocyte loss rate, PBMCs number, NK cell purity of the two methods were compared. NK cells were sorted from PBMCs by three separation and enrichment methods as immunomagnetic bead negative selection method, platelet lysate culture expansion and PERCOLL density gradient separation method, and the purity and yield of NK cells, the activity of NK cells and the tumor-killing ability of the three separation and enrichment methods were compared. [Results] The proportion of NK cells in the lymphocyte population was higher in the manual separation method than in the machine separation method[(13.16±5.16)% vs (8.56±3.92)%, P<0.05]; the number PBMCs was lower in the manual separation method than in the machine separation method[(4.09±1.80)×108vs (6.49±2.16)×108, P<0.05], and there was no difference in the red blood cell loss between the two methods (P>0.05). The purity of NK cells isolated and enriched from PBMCs by manual separation method using immunomagnetic was (96.77±2.31)%; the yield was (56.27±10.47)%; the inhibition of tumor proliferation was (38.67±14.05)%; and the tumor killing rate was (19.90±8.05)%. The purity of NK cells isolated and enriched from PBMCs by manual separation method using platelet lysis culture expansion method was the highest at day 7, which was (54.84±15.80)%; the cell expansion multiple could reach 16.92±6.28 at day 7; the in vitro tumor killing rate of NK cells was (15.83±5.5)%; the tumor inhibition rate was (44.33±13.5)%; and there was no difference in the toxicity and activity of NK cells between the two methods (P>0.05). The purity of NK cells isolated and enriched by PERCOLL density gradient separation method was (15.83±5.82)%, and the yield was (14±6.25)%, which was significantly lower than the other two methods. [Conclusion] PBMCs isolated from whole blood by manual separation and NK cells enriched by negative selection with immunomagnetic beads have the potential to provide NK cell materials for CAR-NK cell therapy, and NK cells enriched by platelet lysate-conditioned medium have the potential to provide NK cells for large-scale NK cell activation reinfusion therapy.
2.The Effect of Fuzheng Huaji Formula (扶正化积方) for Chronic Hepatitis B on Reduction of the Incidence of Liver Cirrhosis and Hepatocellular Carcinoma:A Retrospective Cohort Study
Simiao YU ; Jiahui LI ; Jing JING ; Tingting HE ; Yongqiang SUN ; Liping WANG ; Aozhe ZHANG ; Xiaohe XIAO ; Xia DING ; Ruilin WANG
Journal of Traditional Chinese Medicine 2025;66(3):268-274
ObjectiveTo evaluate the clinical efficacy of Fuzheng Huaji Formula (扶正化积方) for chronic hepatitis B to reduce the incidence of liver cirrhosis and hepatocellular carcinoma. MethodsA retrospective cohort study was conducted, collecting medical records of 118 patients with chronic hepatitis B and 234 patients with hepatitis B-related cirrhosis who visited the hospital between January 1, 2014, and December 31, 2018. The use of Fuzheng Huaji Formula was designated as the exposure factor. Patients receiving antiviral treatment for hepatitis B without concurrent Fuzheng Huaji Formula therapy were included in the western medicine group, while those receiving antiviral treatment combined with Fuzheng Huaji Formula for a cumulative treatment lasting longer than 3 months were included in the combined treatment group. The follow-up observation period was five years. Kaplan-Meier survival analysis was used to assess the cumulative incidence of cirrhosis in patients with chronic hepatitis B and the cumulative incidence of hepatocellular carcinoma in patients with hepatitis B-related cirrhosis. Univariate and multivariate Cox regression analyses were employed to examine the factors influencing the occurrence of cirrhosis and hepatocellular carcinoma. ResultsAmong patients with chronic hepatitis B, there were 55 cases in the combined treatment group and 63 cases in the western medicine group; among patients with hepatitis B-related cirrhosis, there were 110 cases in the combined treatment group and 124 cases in the western medicine group. Five-year follow-up outcomes for chronic hepatitis B patients showed that the cumulative incidence of cirrhosis was 5.45% (3/55) in the combined treatment group and 17.46% (11/63) in the western medicine group, with a statistically significant difference between groups (Z = 2.003, P = 0.045). Five-year follow-up outcomes for hepatitis B-related cirrhosis patients showed that the cumulative incidence of hepatocellular carcinoma was 8.18% (9/110) in the combined treatment group and 22.58% (28/124) in the western medicine group, also showing a statistically significant difference (Z = 3.007, P = 0.003). Univariate and multivariate Cox regression analyses indicated that treatment with Fuzheng Huaji Formula is an independent protective factor in preventing the progression of chronic hepatitis B to cirrhosis and the progression of hepatitis B-related cirrhosis to hepatocellular carcinoma (P<0.05). ConclusionCombining Fuzheng Huaji Formula with antiviral therapy for hepatitis B can effectively intervene in the disease progression of chronic hepatitis B, reducing the incidence of cirrhosis and hepatocellular carcinoma.
3.Changes in renal function in chronic hepatitis B patients treated initially with entecavir versus tenofovir alafenamide fumarate and related influencing factors
Shipeng MA ; Yanqing YU ; Xiaoping WU ; Liang WANG ; Liping LIU ; Yuliang ZHANG ; Xin WAN ; Shanfei GE
Journal of Clinical Hepatology 2025;41(1):44-51
ObjectiveTo investigate the influence of entecavir (ETV) versus tenofovir alafenamide fumarate (TAF) on renal function in previously untreated patients with chronic hepatitis B (CHB). MethodsA retrospective analysis was performed for the clinical data of 167 previously untreated CHB patients who received ETV or TAF treatment for at least 48 weeks at the outpatient service of Department of Infectious Diseases in The First Affiliated Hospital of Nanchang University from September 2019 to November 2023, and according to the antiviral drug used, they were divided into ETV group with 117 patients and TAF group with 50 patients. In order to balance baseline clinical data, propensity score matching (PSM) was used for matching and analysis at a ratio of 2∶1, and the two groups were compared in terms of estimated glomerular filtration rate (eGFR) and the incidence rate of abnormal renal function at week 48. According to eGFR at week 48, the patients were divided into normal renal function group and abnormal renal function group. The independent-samples t test or the Mann-Whitney U test was used for comparison of continuous data between two groups, and the chi-square test or the Fisher’s exact test was used for comparison of categorical data between two groups. The multivariate Logistic regression analysis was used to investigate the influencing factors for abnormal renal function, and the receiver operating characteristic (ROC) curve was used to assess the performance of each indicator in predicting abnormal renal function. The Kaplan-Meier method was used to analyze the cumulative incidence rate of abnormal renal function, and the log-rank test was used for comparison. The analysis of variance with repeated measures was used to compare the dynamic changes of eGFR during antiviral therapy in CHB patients. ResultsAfter PSM matching, there were 100 patients in the ETV group and 50 patients in the TAF group. There were no significant differences in baseline clinical data between the ETV group and the TAF group (all P>0.05), with an eGFR level of 112.29±9.92 mL/min/1.73 m2 in the ETV group and 114.72±12.15 mL/min/1.73 m2 in the TAF group. There was a reduction in eGFR from baseline to week 48 in both groups, and compared with the TAF group at week 48, the ETV group had a significantly lower eGFR (106.42±14.12 mL/min/1.73 m2 vs 112.25±13.44 mL/min/1.73 m2, t=-2.422, P=0.017) and a significantly higher incidence rate of abnormal renal function (17.00% vs 4.00%, χ2=5.092, P=0.024). After the patients were divided into normal renal function group with 131 patients and abnormal renal function group with 19 patients, the univariate analysis showed that there were significant differences between the two groups in age (Z=-2.039, P=0.041), treatment drug (ETV/TAF) (χ2=5.092, P=0.024), and baseline eGFR level (t=4.023, P<0.001), and the multivariate Logistic regression analysis showed that baseline eGFR (odds ratio [OR]=0.896, 95% confidence interval [CI]: 0.841 — 0.955, P<0.001) and treatment drug (OR=5.589, 95%CI: 1.136 — 27.492, P=0.034) were independent influencing factors for abnormal renal function. Baseline eGFR had an area under the ROC curve of 0.781 in predicting abnormal renal function in CHB patients, with a cut-off value of 105.24 mL/min/1.73 m2, a sensitivity of 73.68%, and a specificity of 82.44%. The Kaplan-Meier curve analysis showed that the patients with baseline eGFR≤105.24 mL/min/1.73 m2 had a significantly higher cumulative incidence rate of abnormal renal function than those with baseline eGFR>105.24 mL/min/1.73 m2 (χ2=22.330, P<0.001), and the ETV group had a significantly higher cumulative incidence rate of abnormal renal function than the TAF group (χ2=4.961, P=0.026). With the initiation of antiviral therapy, both the ETV group and the TAF group had a significant reduction in eGFR (F=5.259, P<0.001), but the ETV group only had a significant lower level of eGFR than the TAF group at week 48 (t=-2.422, P=0.017); both the baseline eGFR≤105.24 mL/min/1.73 m2 group and the baseline eGFR>105.24 mL/min/1.73 m2 group had a significant reduction in eGFR (F=5.712, P<0.001), and there was a significant difference in eGFR between the two groups at baseline and weeks 12, 24, 36, and 48 (t=-13.927, -9.780, -8.835, -9.489, and -8.953, all P<0.001). ConclusionFor CHB patients initially treated with ETV or TAF, ETV antiviral therapy has a higher risk of renal injury than TAF therapy at week 48.
4.Relationship between education level and risk of all-cause mortality in middle-aged and elderly people
Ruitai PAN ; Han XUE ; Aolong XYU ; Liping ZHANG ; Lanhua LI
Journal of Public Health and Preventive Medicine 2025;36(1):61-64
Objective To explore the relationship between education level and the risk of all-cause mortality in the middle-aged and elderly (≥45 years old) population in China. Methods Using data from five surveys from 2011-2020, years of education, age, gender, marital status, type of household, alcohol consumption status, smoking status, physical activity, limited ability to perform activities of daily living (ADLs), chronic disease status, and body mass index were collected. According to the survival status,the study participants were divided into a survival group (n=8625) and an all-cause mortality group (n=1735). Cox proportional risk regression model was used to analyze the relationship between years of education and the risk of all-cause mortality in middle-aged and elderly people with stratified analysis. Results The survey was conducted on 10360 research subjects, including 4 983 males and 5 377 females, with an age M(QR) of 59(8) years old. A total of 88 187 person years (average 8.512 person years) were followed up, and a total of 1735 deaths were reported over 9 years. The all-cause mortality rate was 19.674 ‰, with an education period M(QR) of 5(8) years and a survival time M(QR) of 9 (0) years. After adjusting for confounding factors, for every 1 year increase in education, the risk of all-cause mortality decreased by 2.60% [HR=0.974, 95% CI (0.960-0.988)]. The stratified analysis results showed that in the population aged 45-59, for every 1 year increase in education, the risk of all-cause mortality decreased by 1.00% [HR=0.990, 95% CI (0.959,1.021)]; In the population aged 60-74 and over 75, for every 1 year increase in education, the risk of all-cause mortality decreased by 2.70% [HR=0.973, 95% CI (0.948, 0.999)] and 3.50% [HR=0.965, 95% CI (0.929, 1.003)], respectively. Conclusion Improving the education level of middle-aged and elderly people (≥ 45 years old) in China can reduce the risk of all-cause mortality, and elderly education should be vigorously promoted.
5.Analysis of risk factors for post-prematurity respiratory disease in very preterm infants
You YOU ; Jingwen LYU ; Lin ZHOU ; Liping WANG ; Jufeng ZHANG ; Li WANG ; Yongjun ZHANG ; Hongping XIA
Chinese Journal of Pediatrics 2025;63(1):50-54
Objective:To investigate the risk factors associated with post-prematurity respiratory disease (PPRD) in very preterm infants.Methods:A prospective cohort study was conducted, enrolling 369 very preterm infants who were admitted to the neonatal intensive care unit of Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, within one week of birth from January 2019 to June 2023. Data on maternal and infant clinical characteristics, neonatal morbidities, and treatments during hospitalization were collected. The very preterm infants were divided into 2 groups based on whether they developed PPRD. Continuous variables were compared using Mann-Whitney U test, while categorical variables were compared using χ2 tests or continuity correction χ2 test. Multivariate Logistic regression analysis was used to identify the independent risk factors for PPRD in very preterm infants. Results:Among the 369 very preterm infants, 217 cases(58.8%) were male, with a gestational age of 30 (28, 31) weeks at birth and a birth weight of 1 320 (1 085, 1 590) g. Of these, 116 cases (31.4%) developed PPRD, while 253 cases (68.6%) did not. The very preterm infants in the PPRD group had a lower gestational age and lower birth weight (both, P<0.001). The PPRD group also had a higher proportion of males, lower Apgar scores at the 1 th minute after birth and the 5 th minutes after birth, a higher rate of born via cesarean delivery, and a higher incidence of bronchopulmonary dysplasia, more pulmonary surfactant treatment, longer durations of mechanical ventilation, longer total oxygen therapy, and lower Z-score for weight at discharge (all P<0.05). Multivariate Logistic regression analysis showed that gestational age ( OR=0.85, 95% CI 0.73-0.99, P=0.037), born via cesarean delivery ( OR=2.23, 95% CI 1.21-4.10, P=0.010), a duration of mechanical ventilation ≥7 days ( OR=2.51, 95% CI 1.43-4.39, P=0.001), and a Z-score for weight at discharge ( OR=0.82, 95% CI 0.67-0.99, P=0.040) were all independent risk factors for PPRD in very preterm infants. Conclusion:Very preterm infants with a small gestational age, born via cesarean section, mechanical ventilation ≥7 days, and a low Z-score for weight at discharge should be closely monitored for PPRD, and provided with standardized respiratory management after discharge.
6.Multiple applications of metal-organic framework materials in bone tissue engineering and orthopedic disease treatment
Yunxiang LIU ; Xiaoyu ZHANG ; Hao LI ; Rong ZHANG ; Liping LI ; Chongwei CHEN
Chinese Journal of Tissue Engineering Research 2025;29(10):2151-2161
BACKGROUND:Metal-organic frameworks exhibited great potential for bone tissue engineering and bone disease treatment because of its unique merits including tunable porosity,a large specific surface area,good biocompatibility,and easy structure modification. OBJECTIVE:To review the advancements,application,strengths,and weaknesses of metal-organic framework materials in bone repair,arthritis,bone infection,and bone tumors,offering guidance and strategies for future research. METHODS:Web of Science,PubMed,and CNKI databases were searched using Chinese and English keywords"metal-organic frameworks,MOFs,orthopedics,bone repair,bone regeneration,orthopaedic applications,bone tissue engineering,bone infection,arthritis,bone tumor,osteosarcoma"for related literature published from 2015 to 2023.Following initial screening based on inclusion and exclusion criteria,72 articles were finally included for review. RESULTS AND CONCLUSION:(1)During bone repair,metal ions of metal-organic frameworks can induce bone formation by activating specific signaling pathways,which include stimulating osteogenic gene expression,inhibiting osteoclasts,encouraging blood vessel formation,and speeding up bone mineralization.Hence,metal-organic frameworks with metals like calcium,strontium,cobalt,copper,and magnesium ions show significant potential in enhancing bone implant performance.(2)Metal-organic framework materials,especially zinc/cobalt-based metal-organic frameworks,exhibit enzyme-like activities and promote cartilage regeneration by scavenging reactive oxygen species.Compared with natural enzymes,it has the advantages of not easy inactivation and better stability.(3)Zinc-based metal-organic framework materials characterized with wide band gaps,efficient separation and migration of photogenerated carriers,and high stability,the enhancement of photocatalytic activity results from enhancing the excited electron-hole widely used for the eradication of bacteria and tumor cells.(4)Bimetallic metal-organic frameworks,the doping of additional metals,showed critical advantages in optimizing structural performance,such as zinc/magnesium-based metal-organic framework 74 offering increased stability for durable antibacterial activity,and the light absorption capacity and photocatalytic efficiency of tantalum/zirconium-based metal-organic framework greatly improved and thus enhancing the radiation therapy.(5)However,metal-organic framework materials still face challenges in clinical applications,such as the uncertainty of drug release,in vivo safety,and potential immune responses from long-term presence.
7.Degradation dynamics and residue determination of pyriclobenzuron in rice and paddy environments
Huanqi WU ; Junmin WANG ; Kongtan YANG ; Xumi WANG ; Nan FANG ; Liping DUAN ; Changpeng ZHANG ; Xiangyun WANG
Chinese Journal of Schistosomiasis Control 2025;37(2):201-208
Objective To establish a method for determination of pyriclobenzuron (PBU) residues in rice and paddy environments, and to determine the residual amounts and observe the degradation dynamics of PBU. Methods In July 2022, the paddies of Zhejiang Academy of Agricultural Sciences were selected as experimental fields, and were divided into the blank control group (no pesticide application), the 1-fold-concentration pesticide group (1 kg/667 m2), and the 5-fold-concentration pesticide group (5 kg/667 m2), with a 100 m2 area in each group. At the early tillering stage of rice, 20% suspension of PBU sulfate was sprayed once in the 1-fold-concentration and 5-fold-concentration pesticide groups, and rice plants, paddy water and soil samples were collected 2 h, and 1, 2, 3, 5, 7, 11, 14, 21, 28, 35, 49 d and 63 d following spraying PBU, while rice straw, field soil, brown rice and rice husk samples were collected 98 d following spraying. PBU was extracted and purified in samples using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) pretreatment technique, and the PBU contents were determined in samples using ultrahigh performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The solvent standard working solution and matrix standard working solution were prepared. A linear regression equation was fitted between PBU concentration (x-axis) and peak area (y-axis), and the ratio of the slope (k) of the matrix standard curve to the slope (K) of the solvent standard curve was calculated to evaluate the matrix effect of PBU in samples. According to the Guidelines for Pesticide Residue Testing in Crops (NY/T 788—2018), the addition levels of PBU were set at 0.005, 0.050, 5.000, 1 000.000 mg/kg in rice plants, 0.005, 0.050, 2.000, 10.000 mg/kg in paddy water, 0.005, 0.050, 2.000 mg/kg in soil, and 0.005, 0.050, 5.000 mg/kg in brown rice and rice husks. The recovery and relative standard deviation (RSD) of PBU addition were calculated to evaluate the effectiveness of UPLC-MS/MS for determination of PBU contents. The first-order kinetic equation of PBU concentration was fitted in samples at different sampling time points to analyze the trends in PBU degradation in rice plants, paddy water, and soil, and the half-life of PBU was calculated in different samples. Results There was a good linear relationship between the mass concentration and peak area of PBU at concentrations of 0.000 1 to 0.020 0 mg/kg under solvent and matrix conditions (R2 = 0.985 8 to 0.999 7, t = -0.47 to 1.62, all P values < 0.01). The matrix effects of PBU were 70.26%, 65.42% and 65.12% in rice plants, brown rice and rice husks, indicating a matrix-inhibitory effect, and the matrix effect was 87.06% in soils, indicating a weak matrix effect. The recovery of PBU addition was 77.61% to 100.12% in different samples, with RSD of 1.43% to 6.74%, and a limit of quantification (LOQ) of 0.005 mg/kg, and the addition recovery and RSD met the requirements of the Guidelines for Pesticide Residue Testing in Crops (NY/T 788—2018), validating the effectiveness of UPLC-MS/MS assay. Following spraying PBU at a dose of 1 kg/667 m2, the half-life of PBU was 6.24 d in rice plants and 3.43 d in paddy water samples, respectively. The final residues of PBU were lower than the LOQ of 0.005 mg/kg in brown rice and rice husk samples 98 d following spraying PBU. Following spraying PBU at a dose of 5 kg/667 m2, the half-life of PBU was 15.75 d in rice plants and 7.62 d in paddy water samples, respectively. The final residue of PBU was lower than the LOQ of 0.005 mg/kg in brown rice 98 d following spraying PBU, and the final residue of PBU was 0.049 mg/kg in rice husks. Conclusions A simple, and highly accurate and precise UPLC-MS/MS assay has been developed for determination of PBU residues in rice plants and paddy environments through extraction and purification of PBU from matrix samples using QuEChERS pretreatment. After spraying PBU in paddies, the concentration of PBU gradually decreases in rice plants and paddy water over time, and the final residual concentration is low.
8.Stage Differentiation and Treatment of Myasthenia Gravis Based on "Four-Dimensional Pivot-Earth" Qi Transformation Mode
Tianqi HUANG ; Shunning HUANG ; Liping ZHANG ; Changlin QIU ; Ruijie MA ; Kelin HE ; Hui QIU
Journal of Traditional Chinese Medicine 2025;66(11):1178-1181
The connotation of the "four-dimensional pivot-earth" qi transformation mode is a dialectical system of the ascending and descending of yin-yang qi movement, which presented as "the middle Jiao showing earth qi mediating, the left wheel showing water and wood ascending, and the right wheel showing fire and metal converting and descending". Based on this dialectical thinking, it is believed that the core pathogenesis of myasthenia gravis is deficiency of center qi and transportation failure to pivot-earth; the middle-stage characteristics of the disease progression are the loss of mediation of the central qi, resulting in water coldness and wood constraint, and clear yang failing to ascend; the final outcome of this disease is the loss of astringeing of lung metal and qi sinking. The treatment should be based on the rule of qi movement, so for the start-stage, Buzhong Yiqi Decoction (补中益气汤) should be used as the basis to nourish the earth and consolidate the root, and restrengthen the middle qi; for the middle-stage, herbs like Yingyanghuo (Epimedium brevicornu Maxim.), Bajitian (Morinda officinalis How) could be combined to warm the water and soothe the wood, raise yang and boost qi; for the final stage, plus Sini Decoction (四逆汤) to astringe metal to stop collapse, and powerfully supplement original qi. All these medicinals can promote pivot-earth re-transportation, four-dimensional transformation, and regular circulation of qi movement, so as to provide thoughts for improving the clinical effectiveness of myasthenia gravis.
9.Construction and evaluation of a predictive model for the degree of coronary artery occlusion based on adaptive weighted multi-modal fusion of traditional Chinese and western medicine data
Jiyu ZHANG ; Jiatuo XU ; Liping TU ; Hongyuan FU
Digital Chinese Medicine 2025;8(2):163-173
Objective:
To develop a non-invasive predictive model for coronary artery stenosis severity based on adaptive multi-modal integration of traditional Chinese and western medicine data.
Methods:
Clinical indicators, echocardiographic data, traditional Chinese medicine (TCM) tongue manifestations, and facial features were collected from patients who underwent coronary computed tomography angiography (CTA) in the Cardiac Care Unit (CCU) of Shanghai Tenth People's Hospital between May 1, 2023 and May 1, 2024. An adaptive weighted multi-modal data fusion (AWMDF) model based on deep learning was constructed to predict the severity of coronary artery stenosis. The model was evaluated using metrics including accuracy, precision, recall, F1 score, and the area under the receiver operating characteristic (ROC) curve (AUC). Further performance assessment was conducted through comparisons with six ensemble machine learning methods, data ablation, model component ablation, and various decision-level fusion strategies.
Results:
A total of 158 patients were included in the study. The AWMDF model achieved excellent predictive performance (AUC = 0.973, accuracy = 0.937, precision = 0.937, recall = 0.929, and F1 score = 0.933). Compared with model ablation, data ablation experiments, and various traditional machine learning models, the AWMDF model demonstrated superior performance. Moreover, the adaptive weighting strategy outperformed alternative approaches, including simple weighting, averaging, voting, and fixed-weight schemes.
Conclusion
The AWMDF model demonstrates potential clinical value in the non-invasive prediction of coronary artery disease and could serve as a tool for clinical decision support.
10.Distribution characteristics of bacterial communities in central air-conditioning ventilation systems of a Grade 3A hospital in Shanghai based on 16S rRNA sequencing
Jun NI ; Haiyun ZHANG ; Jian CHEN ; Lijun ZHANG ; Yongping LIU ; Xiaojing LI ; Yiming ZHENG ; Liping ZHANG
Journal of Environmental and Occupational Medicine 2025;42(6):732-739
Background A diverse cohort of patients and susceptible individuals congregate in healthcare facilities, where exposure to pathogenic microorganisms associated with respiratory infectious diseases constitutes a significant risk factor for cross-infection. Central air-conditioning ventilation systems improve some indoor environment indicators while exacerbating the risk of transmission of respiratory infectious diseases. Objective To investigate the distribution characteristics of microbial communities in the central air-conditioning ventilation systems of hospitals, providing a scientific basis for the selection of microbial indicators in hygiene standards for hospital central air-conditioning ventilation systems and for hospital risk early warning systems. Methods In October 2023, two central air-conditioning ventilation systems were selected from a Grade 3A hospital in Shanghai: one was an all-air air-conditioning system serving the waiting area on the ground floor, and the other was a fan coil plus fresh air system serving the outpatient area on the third floor. Samples from four different components of the ventilation systems—air outlets, filters, surface coolers, and condensate trays—were collected for high-throughput sequencing of the 16S rRNA gene to analyze bacterial communities. Alpha-diversity and beta-diversity analyses were performed to investigate the microbial community composition and diversity characteristics of the hospital central air-conditioning ventilation systems. Functional analysis was conducted to determine the relative abundance of bacterial functions in these systems.Results A total of 528 operational taxonomic units (OTUs) were identified, encompassing 20 bacterial phyla, 37 classes, 79 orders, 123 families, and 240 genera. The analysis revealed that the bacterial community was predominantly composed of Proteobacteria, Gemmatimonadates, Bacteroidetes, and Actinobacteria. The diversity analysis indicated that bacterial community richness and diversity were highest in the condensate trays, while no statistically significant differences (P > 0.05) were observed in the bacterial community composition among the air outlets, filters, and surface coolers. The functional analysis showed that the bacterial communities in the central air-conditioning ventilation systems primarily exhibited chemoheterotrophic, oxidative energy-dependent heterotrophic, and ureolytic functional characteristics. Conclusion The dominance of Proteobacteria suggests that this phylum exhibits strong adaptability in the central air-conditioning ventilation systems, possibly related to its ability to survive and reproduce under varying environmental conditions. The diversity analysis indicates that the condensate tray is a critical area for bacterial proliferation in the central air-conditioning ventilation systems. The similarity in environmental conditions among the air outlets, filters, and surface coolers result in similar bacterial community structures. The functional analysis reveals that the bacterial communities possess robust energy conversion and metabolic capabilities, potentially contributing to processes such as organic matter decomposition and nitrogen cycling within the central air-conditioning ventilation systems.


Result Analysis
Print
Save
E-mail