ObjectiveTo investigate the mechanism of modified Si Junzitang and Shashen Maidong Tang ［Yiqi Yangyin Jiedu prescription （YQYYJD）］ in enhancing the sensitivity of cisplatin in epidermal growth factor receptor tyrosine kinase inhibitor （EGFR-TKI）-resistant lung adenocarcinoma cells based on aerobic glycolysis. MethodsThe effects of different concentrations of YQYYJD （0， 2， 3， 4， 5， 6， 7， 8 g·L^-1） and cisplatin （0， 3， 6， 9， 12， 15， 18， 21， 24， 27 mg·L^-1） on the proliferation and activity of PC9/GR cells were detected by the cell counting kit-8 （CCK-8） assay after 24 hours of intervention. The half-maximal inhibitory concentration （IC₅₀） for PC9/GR cells was calculated to determine the concentrations used in subsequent experiments. PC9/GR cells were divided into blank group （complete medium）， YQYYJD group （5 g·L^-1）， cisplatin group （12 mg·L^-1）， and combined group （YQYYJD 5 g·L^-1 + cisplatin 12 mg·L^-1）. After 24 hours of intervention， cell viability was measured using CCK-8 assay. Cell proliferation was assessed by colony formation assay， and cell migration was evaluated by scratch and Transwell assays. Glucose consumption， lactate production， and adenosine triphosphate （ATP） levels were measured by colorimetric assays. The expression levels of glycolysis-related proteins， including hexokinase 2 （HK2）， phosphofructokinase P （PFKP）， pyruvate kinase M2 （PKM2）， lactate dehydrogenase A （LDHA）， glucose transporter 1 （GLUT1）， and monocarboxylate transporter 4 （MCT4）， were determined by Western blot. ResultsBoth YQYYJD and cisplatin inhibited the viability of PC9/GR cells in a concentration-dependent manner. The IC₅₀ of PC9/GR cells for YQYYJD and cisplatin were 5.15 g·L^-1 and 12.91 mg·L^-1， respectively. In terms of cell proliferation， compared with the blank group， the cell survival rate and the number of colonies formed in the YQYYJD group， cisplatin group， and combined group were significantly decreased （P<0.01）. Compared with the YQYYJD and cisplatin groups， the combined group showed a further significant reduction in cell survival rate and colony formation （P<0.01）. In terms of cell migration， compared with the blank group， the cell migration rate and the number of cells passing through the Transwell membrane in the YQYYJD group， cisplatin group， and combined group were significantly decreased （P<0.01）. Compared with the YQYYJD and cisplatin groups， the combined group exhibited a further significant reduction in cell migration rate and the number of cells passing through the Transwell membrane （P<0.01）. In terms of glycolysis， compared with the blank group， glucose consumption， lactate production， and ATP levels in the YQYYJD group， cisplatin group， and combined group were significantly decreased （P<0.01）. Compared with the YQYYJD and cisplatin groups， the combined group showed a further significant reduction in glucose consumption， lactate production， and ATP levels （P<0.05）. Compared with the blank group， the protein expression levels of HK2， PFKP， PKM2， and LDHA in the YQYYJD， cisplatin， and combined groups were significantly decreased （P<0.01）. The combined group showed a further significant reduction in the expression levels of these proteins compared with the YQYYJD and cisplatin groups （P<0.01）. No significant differences were observed in the protein expression levels of GLUT1 and MCT4 among the groups. ConclusionYQYYJD can synergistically inhibit the proliferation and migration of PC9/GR cells and enhance their sensitivity to cisplatin. The mechanism may be related to the downregulation of the expression of glycolysis-related rate-limiting enzymes， including HK2， PFKP， PKM2， and LDHA， thereby inhibiting glycolysis.

ObjectiveTo observe the prognosis effect of soluble programmed death ligand-1（sPD-L1） in treating patients with advanced lung adenocarcinoma treated with epidermal growth factor receptor-tyrosine kinase inhibitors（EGFR-TKIs） and the influence of Yiqi Yangyin Jiedu prescription. MethodA prospective cohort-controlled study was conducted to enroll patients treated with EGFR-TKIs in the first line of treatment，who were admitted to the Oncology Department of Longhua Hospital and Shanghai Chest Hospital from May 1^st， 2021 to June 30^th， 2023， and they were evaluated as non-progressive and identified with deficiency of Qi and Yin after one month of treatment. The patients were divided into an exposed group （EGFR-TKIs combined with Yiqi Yangyin Jiedu prescription） and a non-exposed group （EGFR-TKIs alone）according to whether or not they were treated with Yiqi Yangyin Jiedu prescription and were treated until disease progression， or death and intolerable adverse reactions occurred. The enzyme-linked immunosorbent assay （ELISA） was applied to detect the level of sPD-L1 in patients at the time of enrollment and disease progression，and Cox risk proportionality model was used to analyze the independent prognostic factors affecting disease progression of patients treated with EGFR-TKIs. ResultA total of 90 patients （39 in the exposed group and 51 in the non-exposed group） undergoing disease progression after EGFR-TKI treatment were enrolled. At the time of enrolment and after disease progression，the levels of serum sPD-L1 in the 90 patients were 12.06 （27.54） ng·L^-1 and 41.99 （62.93） ng·L^-1，respectively. Compared with that at the time of enrollment， the serum sPD-L1 level in the 90 patients was significantly increased after disease progression （P<0.01）. The serum sPD-L1 level in patients in the exposed group was 12.27 （24.78） ng·L^-1 and 29.57 （61.12）ng·L^-1 respectively at the time of enrolment and after disease progression. In the non-exposed group， patients had serum sPD-L1 levels of 11.81 （28.46） ng·L^-1 and 49.54 （74.12） ng·L^-1 respectively at the time of enrolment and after disease progression. Compared with that at the time of enrollment， the serum sPD-L1 level in the two groups of patients was significantly increased after disease progression （P<0.01）. In addition， compared with that in the non-exposed group， the sPD-L1 level in the exposed group was greatly reduced after disease progression（P<0.01）. Cox multifactorial analysis showed that sPD-L1 level and age at the time of enrolment were associated with patients' progression-free survival（PFS），and that low levels of sPD-L1 （<12.06 ng·L^-1） prolonged the PFS and reduced the risk of disease progression in patients treated with EGFR-TKIs compared with high levels of sPD-L1. ConclusionElevated sPD-L1 level is a poor prognostic factor for the long-term efficacy of EGFR-TKIs，and treatment with Yiqi Yangiin Jiedu prescription can down-regulate sPD-L1 level of patients treated with EGFR-TKIs.

[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.

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.

[Objective] To establish a method for detecting the potency of recombinant human coagulation factor Ⅶa for injection. [Methods] By adding the sample and factor Ⅶ deficient plasma to the sample cup and activating the reaction with prothrombin time assay reagent (PT reagent), the coagulation time of the sample was determined by the change in magnetic bead swing amplitude in the sample cup. The logarithm of coagulation time was inversely proportional to the logarithm of human factor Ⅶa potency. [Results] Under the experimental conditions, the specificity of the methodology was evaluated through spiked recovery, and the recovery rates ranged from 90.0% to 110.0%. Within the range from 0.125 to 1.000 IU/mL, there was a good linear response between the potency and coagulation time of the standard and sample, with correlation coefficients r>0.99. As for the accuracy and repeatability, the recovery rates of various concentrations detected in the stock solution were 101.0%, 100.0% and 112.0%, respectively, with RSD values of 2.6%, 4.0% and 0.0%, respectively. The recovery rates of various concentrations in finished product testing were 104.0%, 94.7% and 112.0%, respectively, with RSD values of 1.9%, 2.4% and 0.0%, respectively. As for the intermediate precision, the RSD were 4.5% and 3.7%, respectively. After treated with sample diluent, the sample was tested at room temperature for 6 hours and still exhibited relatively stable biological activity. [Conclusion] This detection method is accurate, stable, easy to operate and highly automated, and is suitable for detecting the potency of recombinant human coagulation factor Ⅶa for Injection.

Based on the implementation of GMP, comprehensive improvement of quality control measures, and consideration of the 3Rs principle for experimental animals, Several years ago, WHO, the European Pharmacopoeia and the FDA gradually abolished the testing for abnormal toxicity of biological products, and the Chinese Pharmacopoeia 2025 Edition(Volume Ⅲ)also revised the testing for abnormal toxicity of biological products. In order to help users of the Chinese Pharmacopoeia(Volume Ⅲ) better understand and implement this pharmacopoeia, this article provides a detailed review of the changes in regulatory concepts for abnormal toxicity test in various countries and the process of gradually phasing out abnormal toxicity test, as well as the actual situation of China’s pharmaceutical industry. It also interprets the ideas and considerations for revising the Chinese Pharmacopoeia 2025 Edition(Volume Ⅲ) on abnormal toxicity test for biological products.

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.

Objective: To explore the possibility of performing allogeneic platelet-rich plasma (PRP) treatment for patients who were not suitable for autologous PRP collection through case reports of two patients with refractory wounds treated with allogeneic PRP. Methods: The ABO-compatible allogeneic whole blood was centrifuged 3 times to obtain allogeneic PRP within 6 hours of blood collection. Then the qualified allogeneic PRP was applied to 2 cases of refractory wound on the same day. Results: The platelet concentration in allogeneic PRP was higher than 1 000×10 /L, and the test results of infectious diseases, as well as the mixing of red blood cells and white blood cells, met the standard of quality control. Both patients achieved satisfactory wound healing outcomes (3 d). Conclusions: For patients who were not suitable for autologous PRP treatment, allogeneic PRP might be a new option.

Background Di(2-ethylhexyl) phthalate (DEHP) is the most prevalent environmental endocrine disruptor among phthalate acid esters (PAEs) worldwide. Previous studies have indicated that exposure to DEHP may disrupt glucose metabolism. Objective To investigate the impact of DEHP on glucose homeostasis in rats, focusing on oxidative stress-induced impairment of autophagy in islet β cells. Methods Forty male SD rats were randomly assigned to four groups, receiving DEHP doses of 0, 187, 375, and 750 mg·kg⁻¹ for 12 weeks. Oral glucose tolerance (OGTT) and insulin tolerance tests (ITT) were conducted 24 h after the final exposure. Pancreatic microstructural alterations were assessed using hematoxylin and eosin (HE) staining and transmission electron microscopy (TEM). Commercial ELISA kits were employed to quantify the levels of insulin, adenosine triphosphate (ATP), and adenosine monophosphate (AMP) in rat serum, as well as the protein expression level of activated caspase-3 in pancreatic tissue. Additionally, commercial microplate kits were utilized to measure the concentration of reduced glutathione (GSH) in serum, the activity of superoxide dismutase (SOD) using water-soluble tetrazolium salt-1, the content of malondialdehyde (MDA) by thiobarbituric acid method, and the level of reactive oxygen species (ROS) in pancreatic tissue by chemical fluorescence method. Reverse transcription polymerase chain reaction (RT-PCR) was used to measure sequestosome1 (SQSTM1/p62), Beclin1, microtubule-associated protein 1 light chain 3 (LC3), and cysteinyl aspartate specific proteinase-8 (Caspase-8) mRNA levels. Western blot analysis was applied to detect the protein relative expression levels of p62, Beclin-1, LC3-I, LC3 II, AMPK, p-AMPK, mTOR, p-mTOR, ULK1, and Caspase-8. Results Compared to the 0 mg·kg⁻¹ DEHP group, the 750 mg·kg⁻¹ DEHP group exhibited a significant increase in fasting blood glucose levels at 2, 4, 6, and 12 weeks (P<0.05). The OGTT showed that, following high-glucose gavage, the 187 mg·kg⁻¹ DEHP group had elevated blood glucose at 30 min (P<0.05), the 375 mg·kg⁻¹ DEHP group showed increased glucose levels at 15, 30, and 180 min (P<0.05), and the 750 mg·kg⁻¹ DEHP group exhibited elevated levels at 15, 30, 60, and 180 min (P<0.05). The 375 and 750 mg·kg⁻¹ DEHP groups demonstrated significantly increased OGTT area under the curve (AUC) values (P<0.05). In contrast, ITT results indicated no significant differences in blood glucose levels or AUC among the DEHP exposure groups at all time points (P>0.05). Compared to the 0 mg·kg⁻¹ DEHP group, the 750 mg·kg⁻¹ DEHP group exhibited significantly higher HOMA-IR levels and markedly lower HOMA-ISI values (P<0.05). HE and TEM showed that in each DEHP exposure group, the number of islet cells decreased, the islet area reduced, and chromatin condensation occurred. The endocrine granules in the cytoplasm of islet β cells decreased, and there were varying degrees of widening of the nuclear membrane gap, flattening and expansion of the Golgi complex, and expansion of the endoplasmic reticulum. Ribosome separation was observed, and autophagosomes were visible. In the 375 and 750 mg·kg⁻¹ DEHP groups, the mitochondria were deformed to varying degrees, and some cristae structures disappeared, presenting vacuolization. Moreover, the chromatin condensation in the nuclei was more severe in the 750 mg·kg⁻¹ DEHP group. The serum SOD activity was significantly elevated in the 750 mg·kg⁻¹ DEHP group (P<0.05). Both the 375 mg·kg⁻¹ and 750 mg·kg⁻¹ DEHP groups exhibited a significant increase in the relative ROS content in pancreatic tissue (P<0.05). In DEHP-treated groups, the MDA content increased (P<0.05), while the GSH content decreased (P<0.05). Additionally, in the 750 mg·kg⁻¹ DEHP group, the AMP/ATP ratio in serum was significantly raised (P<0.05), and the expression of cleaved Caspase-3 protein in pancreatic tissue was also significantly increased (P<0.05). The relative mRNA levels of p62, Beclin-1, LC3, and Caspase-8 in the pancreatic tissue of rats exposed to DEHP were significantly elevated (P<0.05). The relative expression levels of p-AMPK/AMPK, p-ULK1/ULK1, and Beclin-1 proteins in the DEHP-treated groups were significantly increased (P<0.05). In the 375 mg·kg⁻¹ and 750 mg·kg⁻¹ DEHP treatment groups, the relative expression levels of p62, LC3 II/LC1, and Caspase-8 proteins were significantly increased (P<0.05), while the relative expression level of p-mTOR/mTOR was significantly decreased (P<0.05). Conclusion DEHP can disrupt glucose homeostasis by inducing oxidative stress, which subsequently activates autophagy via the ROS/AMPK/ULK1 pathway, impairing autophagic flux and promoting apoptosis of islet β cells, ultimately decreasing their function and number.

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.