1.Effects of ammonia poisoning on cognitive behavior and hippocampal synaptic damage in mice
Jiuxuan ZHANG ; Jinnan ZHANG ; Xiaofan SUI ; Xiaxia PEI ; Jianhong WEI ; Qiang SU ; Tian LI
Chinese Journal of Tissue Engineering Research 2026;30(5):1122-1128
BACKGROUND:Ammonia poisoning is considered to be the main hypothesis for the pathogenesis of hepatic encephalopathy.Ammonia can lead to psychiatric and cognitive behavioral disorders,although the specific pathological molecular mechanisms remain unclear.OBJECTIVE:To investigate the effects of ammonia poisoning on cognitive behavior and hippocampal neuronal synapses in mice.METHODS:Thirty-two C57BL/6J mice were randomly divided into a normal control group and an ammonium chloride group,with 16 mice in each group.Normal saline was injected intraperitoneally in the control group,and ammonium chloride(10 mmol/kg)was injected intraperitoneally in the ammonium chloride group to construct a model of ammonia poisoning,once a day.After 7 days of ammonium chloride intervention,blood samples were collected from the hearts of six mice in each group for blood ammonia concentration detection.Behavioral experiments,including the open field test,novel object recognition test,and Y-maze test,were performed to assess mental and cognitive-behavioral changes in mice.Finally,hippocampal tissues were extracted for western blot analysis to detect the expression levels of synaptophysin and postsynaptic density protein-95 in hippocampal neurons.RESULTS AND CONCLUSION:The blood ammonia concentration was significantly elevated in the ammonium chloride group compared with the control group(P<0.05).Mice in the ammonium chloride group showed anxiety-like behavior and disinhibition phenomenon,and a significant decrease in recognition memory and working memory ability.Western blot results revealed that the expression of synaptophysin and postsynaptic density protein-95 protein in hippocampal neurons in the ammonium chloride group was lower than that in the control group(P<0.05).To conclude,ammonia poisoning can induce hippocampal neuronal synaptic damage,leading to psychiatric and cognitive behavioral abnormalities in mice.
2.Effects of ammonia poisoning on cognitive behavior and hippocampal synaptic damage in mice
Jiuxuan ZHANG ; Jinnan ZHANG ; Xiaofan SUI ; Xiaxia PEI ; Jianhong WEI ; Qiang SU ; Tian LI
Chinese Journal of Tissue Engineering Research 2026;30(5):1122-1128
BACKGROUND:Ammonia poisoning is considered to be the main hypothesis for the pathogenesis of hepatic encephalopathy.Ammonia can lead to psychiatric and cognitive behavioral disorders,although the specific pathological molecular mechanisms remain unclear.OBJECTIVE:To investigate the effects of ammonia poisoning on cognitive behavior and hippocampal neuronal synapses in mice.METHODS:Thirty-two C57BL/6J mice were randomly divided into a normal control group and an ammonium chloride group,with 16 mice in each group.Normal saline was injected intraperitoneally in the control group,and ammonium chloride(10 mmol/kg)was injected intraperitoneally in the ammonium chloride group to construct a model of ammonia poisoning,once a day.After 7 days of ammonium chloride intervention,blood samples were collected from the hearts of six mice in each group for blood ammonia concentration detection.Behavioral experiments,including the open field test,novel object recognition test,and Y-maze test,were performed to assess mental and cognitive-behavioral changes in mice.Finally,hippocampal tissues were extracted for western blot analysis to detect the expression levels of synaptophysin and postsynaptic density protein-95 in hippocampal neurons.RESULTS AND CONCLUSION:The blood ammonia concentration was significantly elevated in the ammonium chloride group compared with the control group(P<0.05).Mice in the ammonium chloride group showed anxiety-like behavior and disinhibition phenomenon,and a significant decrease in recognition memory and working memory ability.Western blot results revealed that the expression of synaptophysin and postsynaptic density protein-95 protein in hippocampal neurons in the ammonium chloride group was lower than that in the control group(P<0.05).To conclude,ammonia poisoning can induce hippocampal neuronal synaptic damage,leading to psychiatric and cognitive behavioral abnormalities in mice.
3.Advances in genomics of SGLT2 and clinical application of SGLT2 inhibitors
Xiaoxia DENG ; Jing TIAN ; Jianfen SU
Journal of Pharmaceutical Practice and Service 2026;44(5):228-232
Sodium-glucose cotransporter 2 (SGLT2) is involved in most glucose reabsorption in the kidney. Inhibition of SGLT2 leads to the excretion of glucose through urine and represents an important concept in the treatment of type 2 diabetes. With the development of pharmacogenomics, it was found that SGLT2 gene polymorphism had certain effects on fasting blood glucose, glycosylated hemoglobin and insulin levels, and may affect the risk of type 2 diabetes and response to treatment with SGLT2 inhibitors, which is of great significance in the treatment of T2DM. Domestic and international studies on SGLT2 gene polymorphism were reviewed and effects of SGLT2 inhibitor (SGLT2i) in the treatment of T2DM were discussed in this paper.
4.Advancements in the application of gas chromatography-ion migration spectrometry(GC-IMS)in traditional Chinese medicine research
Haiyun WU ; Tian YANG ; Chi ZHANG ; Wenyi LIANG ; Juan SU
Journal of Pharmaceutical Practice and Service 2026;44(7):341-345
Traditional Chinese medicine contains a variety of volatile components (VOCs) such as terpenes and aliphatics, which have significant pharmacological activities, and are commonly analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Although the separation ability is strong, the samples need to be pre-treated and the analysis time is long. In recent years, the combination of GC and ion migration spectrometry (IMS) has been widely used in the academic community. The combination of high separation ability of GC and rapid reaction ability of IMS has the advantages of no sample pretreatment, fast analysis time, low detection limit and simple operation. It is increasingly used in traditional Chinese medicine research. The working principle of GC-IMS was introduced, the application in VOCs research of traditional Chinese medicine was summarized, and the future development direction was prospected in this paper.
5.PPARα activation alleviates lithocholic acid-induced liver injury by inhibiting pyroptosis
Hang-Fei Liang ; Chuo-Ying Mai ; Xuan Li ; Jia-Ning Tian ; Hai-Guo Su ; Min Huang ; Jian-Hong Fang ; Hai-Tao Wang ; Xiao Yang ; Hui-Chang Bi
Liver Research 2026;10(2):177-188
Background and aims
The mechanism of cholestatic liver injury (CLI) is unclear, and effective therapies are lacking. While peroxisome proliferator-activated receptor alpha (PPARα) agonists show potential hepatoprotective effect and pyroptosis is implicated in hepatocellular damage, how PPARα activation mitigates lithocholic acid (LCA)-induced pyroptosis remains unknown.
Methods
The hepatoprotective effect of PPARα agonists was evaluated in a mouse model of intrahepatic cholestasis induced by LCA. Liver injury was assessed via serum biochemistry, hematoxylin and eosin and TUNEL staining, and electron microscopy. Pyroptosis pathways were analyzed using real-time quantitative polymerase chain reaction, Western blot, and co-immunoprecipitation.
Results
Combined morphological, histopathological, and biochemical analyses confirmed that PPARα activation protects against CLI. Compared with LCA treatment alone, PPARα activation significantly attenuated the elevation of serum lactate dehydrogenase (LDH), the increased TUNEL-positive cells, and the formation of hepatocyte membrane pores. Mechanistically, PPARα activation suppressed both NOD-like receptor protein 3 (NLRP3) inflammasome-mediated pyroptosis and apoptosis protease-activating factor-1 (APAF-1)/CASPASE-3/GSDME-mediated pyroptosis. Furthermore, PPARα agonist pretreatment inhibited activation of the nuclear factor-kappa B (NF-κB) and forkhead box O1 (FOXO1) signaling pathways.
Conclusions
PPARα protects against LCA-induced CLI by inhibiting both NLRP3 inflammasome-mediated pyroptosis associated with NF-κB and APAF-1/CASPASE-3/GSDME-mediated pyroptosis associated with the FOXO1 signaling pathway.
6.Mechanism of Xuefu Zhuyutang in Intervening in Ferroptosis in Rats with Coronary Heart Disease with Blood Stasis Syndrome Based on ACSL4 Signalling Pathway
Yi LIU ; Yang YANG ; Chang SU ; Peng TIAN ; Mingyun WANG ; Ruqian ZHONG ; Xuejiao XIE ; Qing YAN ; Qinghua PENG ; Qiuyan ZHANG
Chinese Journal of Experimental Traditional Medical Formulae 2025;31(6):27-38
ObjectiveTo investigate the mechanism of ferroptosis mediated by long-chain acyl-CoA synthetase 4 (ACSL4) signalling pathway in rats with coronary heart disease with blood stasis syndrome and the intervention effect of Xuefu Zhuyutang. MethodsSPF male SD rats were randomly divided into normal group, sham-operation group, model group, trimetazidine group (5.4 mg·kg-1), low-, medium-, and high-dose group (3.51, 7.02,14.04 g·kg-1) of Xuefu Zhuyutang. The coronary artery left anterior descending ligation method was used to prepare a model of coronary heart disease with blood stasis syndrome, and continuous treatment for 7 d was conducted, while the sham-operation group was only threaded and not ligated. The general macroscopic symptoms of the rats were observed, and indicators such as electrocardiogram, echocardiography, and blood rheology were detected. The pathological morphology of myocardial tissue was observed by hematoxylin-eosin (HE) staining, and the changes in mitochondria in myocardial tissue were observed by transmission electron microscopy. The level of iron deposition in myocardial tissue was observed by Prussian blue staining. The levels of 12-hydroxyeicosatetraenoic acid (12-HETE) and 15-HETE were detected in serum by enzyme-linked immunosorbent assay. A biochemical colourimetric assay was used to detect the levels of Fe2+, lipid peroxidation (LPO), glutathione (GSH), and T-GSH/glutathione disulfide (GSSG) in myocardial tissue. DCFH-DA fluorescence quantitative assay was employed to detect the levels of reactive oxygen species (ROS). Western blot and Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) was adopted to detect the protein and mRNA expressions of glutathione peroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), ACSL4, and ly-sophosphatidylcholine acyltransferase3 (LPCAT3) in myocardial tissue. ResultsCompared with those in the normal group, the rats in the model group were poor in general macroscopic symptoms. The electrocardiogram showed widened QRS wave amplitude and increased voltage, bow-back elevation of the ST segments, elevated T waves, J-point elevation, and accelerated heart rate. Echocardiography showed a significant reduction in left ventricular ejection fraction (LVEF) and left ventricular fraction shortening (LVFS) (P<0.01). Blood rheology showed that the viscosity of the whole blood (low, medium, and high rate of shear) was significantly increased (P<0.01). HE staining showed an abnormal structure of myocardial tissue. There was a large area of myocardial necrosis and inflammatory cell infiltration and a large number of connective tissue between myocardial fibers. Transmission electron microscopy showed that the mitochondria were severely atrophy or swelling. The cristae were reduced or even broken, and the matrix was flocculent or even vacuolated. Prussian blue staining showed that there were a large number of iron-containing particles, and the iron deposition was obvious. The content of 12-HETE and 15-HETE in the serum was significantly increased (P<0.01). The content of Fe2+, LPO, and ROS in myocardial tissue was significantly increased (P<0.01). The content of GSH was significantly decreased (P<0.01), and T-GSH/GSSG was decreased (P<0.01). The protein and mRNA expressions of GPX4 and FTH1 in myocardial tissue were both significantly decreased (P<0.05, P<0.01), while those of ACSL4 and LPCAT3 increased significantly (P<0.01). Compared with the model group, the general macroscopic symptoms and electrocardiogram results of rats in low-, medium- and high-dose groups of Xuefu Zhuyutang were alleviated, and the differences in LVEF/LVFS ratios were all significantly increased (P<0.05, P<0.01). The differences in whole-blood viscosity (low, medium, and high rate of shear) were all significantly decreased (P<0.01). The results of HE staining and transmission electron microscopy showed that the morphology, structure, and mitochondria of cardiomyocytes were improved. The content of 12-HETE and 15-HETE in serum was reduced to different degrees in low-, medium-, and high-dose groups of Xuefu Zhuyutang (P<0.05, P<0.01). The content of Fe2+, LPO, and ROS was significantly reduced in the medium- and high-dose groups of Xuefu Zhuyutang (P<0.05, P<0.01), and the content of GSH and T-GSH/GSSG was significantly increased (P<0.05, P<0.01). The protein and mRNA expressions of GPX4 and FTH1 were significantly increased to varying degrees in the medium- and high-dose groups of Xuefu Zhuyutang (P<0.05, P<0.01), and ACSL4 and LPCAT3 were decreased to different degrees in the low-, medium-, and high-dose groups of Xuefu Zhuyutang (P<0.05, P<0.01). ConclusionXuefu Zhuyutang can regulate iron metabolism and anti-lipid oxidation reaction to mediate ferroptosis through the ACSL4 signalling pathway, thus exerting a protective effect on rats with coronary heart disease with blood stasis syndrome.
7.Changing antimicrobial resistance profiles of Burkholderia cepacia in hospitals across China:results from CHINET Antimicrobial Resistance Surveillance Program,2015-2021
Chunyue GE ; Yunjian HU ; Xiaoman AI ; Yang YANG ; Fupin HU ; Demei ZHU ; Yingchun XU ; Xiaojiang ZHANG ; Hui LI ; Ping JI ; Yi XIE ; Mei KANG ; Chuanqing WANG ; Pan FU ; Yuanhong XU ; Ying HUANG ; Ziyong SUN ; Zhongju CHEN ; Yuxing NI ; Jingyong SUN ; Yunzhuo CHU ; Sufei TIAN ; Zhidong HU ; Jin LI ; Yunsong YU ; Jie LIN ; Bin SHAN ; Yan DU ; Sufang GUO ; Lianhua WEI ; Fengmei ZOU ; Hong ZHANG ; Chun WANG ; Chao ZHUO ; Danhong SU ; Dawen GUO ; Jinying ZHAO ; Hua YU ; Xiangning HUANG ; Wen'en LIU ; Yanming LI ; Yan JIN ; Chunhong SHAO ; Xuesong XU ; Chao YAN ; Shanmei WANG ; Yafei CHU ; Lixia ZHANG ; Juan MA ; Shuping ZHOU ; Yan ZHOU ; Lei ZHU ; Jinhua MENG ; Fang DONG ; Zhiyong LÜ ; Fangfang HU ; Han SHEN ; Wanqing ZHOU ; Wei JIA ; Gang LI ; Jinsong WU ; Yuemei LU ; Jihong LI ; Jinju DUAN ; Jianbang KANG ; Xiaobo MA ; Yanping ZHENG ; Ruyi GUO ; Yan ZHU ; Yunsheng CHEN ; Qing MENG ; Shifu WANG ; Xuefei HU ; Jilu SHEN ; Wenhui HUANG ; Ruizhong WANG ; Hua FANG ; Bixia YU ; Yong ZHAO ; Ping GONG ; Kaizhen WENG ; Yirong ZHANG ; Jiangshan LIU ; Longfeng LIAO ; Hongqin GU ; Lin JIANG ; Wen HE ; Shunhong XUE ; Jiao FENG ; Chunlei YUE
Chinese Journal of Infection and Chemotherapy 2025;25(5):557-562
Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1%(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5%,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3%(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1%)were isolated from sputum and respiratory secretions,followed by urine(10.7%)and blood samples(8.1%).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1%.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4%in the patients<18 years old to 20.6%in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.
8.PLUNC downregulates the expression of PD-L1 by inhibiting the interaction of DDX17/β-catenin in nasopharyngeal carcinoma
Ranran FENG ; Yilin GUO ; Meilin CHEN ; Ziying TIAN ; Yijun LIU ; Su JIANG ; Jieyu ZHOU ; Qingluan LIU ; Xiayu LI ; Wei XIONG ; Lei SHI ; Songqing FAN ; Guiyuan LI ; Wenling ZHANG
Journal of Pathology and Translational Medicine 2025;59(1):68-83
Background:
Nasopharyngeal carcinoma (NPC) is characterized by high programmed death-ligand 1 (PD-L1) expression and abundant infiltration of non-malignant lymphocytes, which renders patients potentially suitable candidates for immune checkpoint blockade therapies. Palate, lung, and nasal epithelium clone (PLUNC) inhibit the growth of NPC cells and enhance cellular apoptosis and differentiation. Currently, the relationship between PLUNC (as a tumor-suppressor) and PD-L1 in NPC is unclear.
Methods:
We collected clinical samples of NPC to verify the relationship between PLUNC and PD-L1. PLUNC plasmid was transfected into NPC cells, and the variation of PD-L1 was verified by western blot and immunofluorescence. In NPC cells, we verified the relationship of PD-L1, activating transcription factor 3 (ATF3), and β-catenin by western blot and immunofluorescence. Later, we further verified that PLUNC regulates PD-L1 through β-catenin. Finally, the effect of PLUNC on β-catenin was verified by co-immunoprecipitation (Co-IP).
Results:
We found that PLUNC expression was lower in NPC tissues than in paracancer tissues. PD-L1 expression was opposite to that of PLUNC. Western blot and immunofluorescence showed that β-catenin could upregulate ATF3 and PD-L1, while PLUNC could downregulate ATF3/PD-L1 by inhibiting the expression of β-catenin. PLUNC inhibits the entry of β-catenin into the nucleus. Co-IP experiments demonstrated that PLUNC inhibited the interaction of DEAD-box helicase 17 (DDX17) and β-catenin.
Conclusions
PLUNC downregulates the expression of PD-L1 by inhibiting the interaction of DDX17/β-catenin in NPC.
9.Changing prevalence and antibiotic resistance profiles of carbapenem-resistant Enterobacterales in hospitals across China:data from CHINET Antimicrobial Resistance Surveillance Program,2015-2021
Wenxiang JI ; Tong JIANG ; Jilu SHEN ; Yang YANG ; Fupin HU ; Demei ZHU ; Yuanhong XU ; Ying HUANG ; Fengbo ZHANG ; Ping JI ; Yi XIE ; Mei KANG ; Chuanqing WANG ; Pan FU ; Yingchun XU ; Xiaojiang ZHANG ; Ziyong SUN ; Zhongju CHEN ; Yuxing NI ; Jingyong SUN ; Yunzhuo CHU ; Sufei TIAN ; Zhidong HU ; Jin LI ; Yunsong YU ; Jie LIN ; Bin SHAN ; Yan DU ; Sufang GUO ; Lianhua WEI ; Fengmei ZOU ; Yunjian HU ; Xiaoman AI ; Chao ZHUO ; Danhong SU ; Dawen GUO ; Jinying ZHAO ; Hua YU ; Xiangning HUANG ; Wen'en LIU ; Yanming LI ; Yan JIN ; Chunhong SHAO ; Xuesong XU ; Chao YAN ; Shanmei WANG ; Yafei CHU ; Lixia ZHANG ; Juan MA ; Shuping ZHOU ; Yan ZHOU ; Lei ZHU ; Jinhua MENG ; Fang DONG ; Zhiyong LÜ ; Fangfang HU ; Han SHEN ; Wanqing ZHOU ; Wei JIA ; Gang LI ; Jinsong WU ; Yuemei LU ; Jihong LI ; Jinju DUAN ; Jianbang KANG ; Xiaobo MA ; Yanping ZHENG ; Ruyi GUO ; Yan ZHU ; Yunsheng CHEN ; Qing MENG ; Shifu WANG ; Xuefei HU ; Hong ZHANG ; Chun WANG ; Wenhui HUANG ; Ruizhong WANG ; Hua FANG ; Bixia YU ; Yong ZHAO ; Ping GONG ; Kaizhen WENG ; Yirong ZHANG ; Jiangshan LIU ; Longfeng LIAO ; Hongqin GU ; Lin JIANG ; Wen HE ; Shunhong XUE ; Jiao FENG ; Chunlei YUE
Chinese Journal of Infection and Chemotherapy 2025;25(4):445-454
Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43%(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38%,9.73%,and 8.47%,respectively.The prevalence of CRE strains in Escherichia coli was 1.99%.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)%,followed by blood(20.88±3.40)%and urine(18.40±3.45)%.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)%.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.
10.Changing distribution and antibiotic resistance profiles of the respiratory bacterial isolates in hospitals across China:data from CHINET Antimicrobial Resistance Surveillance Program,2015-2021
Ying FU ; Yunsong YU ; Jie LIN ; Yang YANG ; Fupin HU ; Demei ZHU ; Yingchun XU ; Xiaojiang ZHANG ; Fengbo ZHANG ; Ping JI ; Yi XIE ; Mei KANG ; Chuanqing WANG ; Pan FU ; Yuanhong XU ; Ying HUANG ; Ziyong SUN ; Zhongju CHEN ; Yuxing NI ; Jingyong SUN ; Yunzhuo CHU ; Sufei TIAN ; Zhidong HU ; Jin LI ; Bin SHAN ; Yan DU ; Sufang GUO ; Lianhua WEI ; Fengmei ZOU ; Hong ZHANG ; Chun WANG ; Yunjian HU ; Xiaoman AI ; Chao ZHUO ; Danhong SU ; Dawen GUO ; Jinying ZHAO ; Hua YU ; Xiangning HUANG ; Wen'en LIU ; Yanming LI ; Yan JIN ; Chunhong SHAO ; Xuesong XU ; Chao YAN ; Shanmei WANG ; Yafei CHU ; Lixia ZHANG ; Juan MA ; Shuping ZHOU ; Yan ZHOU ; Lei ZHU ; Jinhua MENG ; Fang DONG ; Zhiyong LÜ ; Fangfang HU ; Han SHEN ; Wanqing ZHOU ; Wei JIA ; Gang LI ; Jinsong WU ; Yuemei LU ; Jihong LI ; Jinju DUAN ; Jianbang KANG ; Xiaobo MA ; Yanping ZHENG ; Ruyi GUO ; Yan ZHU ; Yunsheng CHEN ; Qing MENG ; Shifu WANG ; Xuefei HU ; Jilu SHEN ; Ruizhong WANG ; Hua FANG ; Bixia YU ; Yong ZHAO ; Ping GONG ; Kaizhen WENG ; Yirong ZHANG ; Jiangshan LIU ; Longfeng LIAO ; Hongqin GU ; Lin JIANG ; Wen HE ; Shunhong XUE ; Jiao FENG ; Chunlei YUE ; Wenhui HUANG
Chinese Journal of Infection and Chemotherapy 2025;25(4):431-444
Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6%of the isolates were Gram-negative bacteria and 17.4%were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)%and(94.0±0.1)%,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P<0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9%.The prevalence of penicillin-resistant S.pneumoniae was 1.4%.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8%and 41.3%,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7%,20.8%,9.4%,29.8%,and 73.3%,respectively.The prevalence of β-lactamase was 96.1%in Moraxella catarrhalis and 60.0%in Haemophilus influenzae.The H.influenzae isolates from children(<18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P<0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.


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