1.Effects and mechanisms of swimming for inhibiting traumatic joint contracture in a rat model
Xiaoping SHUI ; Chunying LI ; Xin ZHANG ; Bin LI ; Chao FENG ; Hongyu ZHOU ; Ke CHEN ; Yingying LIAO
Chinese Journal of Tissue Engineering Research 2025;29(2):262-268
BACKGROUND:Early exercise treatment is the main prevention way for traumatic joint contracture and is also a research focus.Swimming may be a potential intervention for joint contracture due to the special physical properties of water. OBJECTIVE:To explore the effects of swimming on the development of joint contracture in a rat model and study its mechanisms. METHODS:Twenty-four Sprague-Dawley rats were randomly divided into a blank control group(n=8)and a joint contracture group(n=16).After the surgical operation of knee joint contracture rat models,the joint contracture group was randomly subdivided into a surgical control group(n=8)and a swimming treatment group(n=8).Swimming started in the swimming treatment group in the second week after surgery and lasted for a total of 5 weeks.At the 6th week after surgery,the body mass,knee joint range of motion,and quadriceps diameter were tested,and the diameter/body mass index was calculated.Hematoxylin-eosin staining was performed to detect the pathological changes in the knee joint capsule and quadriceps muscle,and Masson staining was used to observe fibrotic changes in the knee joint capsule.Furthermore,the protein expression of transforming growth factor β1 and type I collagen in the knee joint capsule was quantified by immunohistochemical assay and western blot was performed to detect the protein expression of MuRF1 in the quadriceps femoris. RESULTS AND CONCLUSION:Compared with the blank control group,the knee range of motion decreased in the surgical control and swimming treatment groups(P<0.01),and knee extension deficit and arthrogenic extension deficit were significantly increased(P<0.01),the diameter of the quadriceps muscle was decreased(P<0.01),the joint capsule showed significant fibrosis,the quadriceps muscle was atrophied,and the diameter/body mass index was decreased(P<0.01).Compared with the surgical control group,the swimming treatment group showed a significant increase in knee joint range of motion and quadriceps diameter(P<0.01),and significant improvement in joint capsule fibrosis and quadriceps atrophy.Compared with the blank control group,collagen fiber content and expression of transforming growth factor β1 and type I collagen were increased in the joint capsule of rats in both the surgical control group and the swimming treatment group(P<0.01).Compared with the surgical control group,collagen fiber content and expression of transforming growth factor β1 and type I collagen protein in the joint capsule were decreased in the swimming treatment group.Compared with the blank control group,the expression of MuRF1 protein in the quadriceps muscle of rats in the surgical control group and the swimming treatment group was increased(P<0.05).Compared with the surgical control group,the expression of MuRF1 protein in the quadriceps muscle of rats in the swimming treatment group was decreased(P<0.05).To conclude,early swimming intervention reduces transforming growth factor β1 and type I collagen expression in the joint capsule of traumatic joint contracture rats,decreases MuRF1 expression in the quadriceps muscle,and increases joint range of motion and quadriceps diameter,thereby inhibiting the development of joint contracture.
2.Targeting TM4SF1 promotes tumor senescence enhancing CD8+ T cell cytotoxic function in hepatocellular carcinoma
Weifeng ZENG ; Furong LIU ; Yachong LIU ; Ze ZHANG ; Haofan HU ; Shangwu NING ; Hongwei ZHANG ; Xiaoping CHEN ; Zhibin LIAO ; Zhanguo ZHANG
Clinical and Molecular Hepatology 2025;31(2):489-508
Background/Aims:
Transmembrane 4 L six family member 1 (TM4SF1) is highly expressed and contributes to the progression of various malignancies. However, how it modulates hepatocellular carcinoma (HCC) progression and senescence remains to be elucidated.
Methods:
TM4SF1 expression in HCC samples was evaluated using immunohistochemistry and flow cytometry. Cellular senescence was assessed through SA-β-gal activity assays and Western blot analysis. TM4SF1-related protein interactions were investigated using immunoprecipitation-mass spectrometry, co-immunoprecipitation, bimolecular fluorescence complementation, and immunofluorescence. Tumor-infiltrating immune cells were analyzed by flow cytometry. The HCC mouse model was established via hydrodynamic tail vein injection.
Results:
TM4SF1 was highly expressed in human HCC samples and murine models. Knockdown of TM4SF1 suppressed HCC proliferation both in vitro and in vivo, inducing non-secretory senescence through upregulation of p16 and p21. TM4SF1 enhanced the interaction between AKT1 and PDPK1, thereby promoting AKT phosphorylation, which subsequently downregulated p16 and p21. Meanwhile, TM4SF1-mediated AKT phosphorylation enhanced PD-L1 expression while reducing major histocompatibility complex class I level on tumor cells, leading to impaired cytotoxic function of CD8+ T cells and an increased proportion of exhausted CD8+ T cells. In clinical HCC samples, elevated TM4SF1 expression was associated with resistance to anti-PD-1 immunotherapy. Targeting TM4SF1 via adeno-associated virus induced tumor senescence, reduced tumor burden and synergistically enhanced the efficacy of anti-PD-1 therapy.
Conclusions
Our results revealed that TM4SF1 regulated tumor cell senescence and immune evasion through the AKT pathway, highlighting its potential as a therapeutic target in HCC, particularly in combination with first-line immunotherapy.
3.Targeting TM4SF1 promotes tumor senescence enhancing CD8+ T cell cytotoxic function in hepatocellular carcinoma
Weifeng ZENG ; Furong LIU ; Yachong LIU ; Ze ZHANG ; Haofan HU ; Shangwu NING ; Hongwei ZHANG ; Xiaoping CHEN ; Zhibin LIAO ; Zhanguo ZHANG
Clinical and Molecular Hepatology 2025;31(2):489-508
Background/Aims:
Transmembrane 4 L six family member 1 (TM4SF1) is highly expressed and contributes to the progression of various malignancies. However, how it modulates hepatocellular carcinoma (HCC) progression and senescence remains to be elucidated.
Methods:
TM4SF1 expression in HCC samples was evaluated using immunohistochemistry and flow cytometry. Cellular senescence was assessed through SA-β-gal activity assays and Western blot analysis. TM4SF1-related protein interactions were investigated using immunoprecipitation-mass spectrometry, co-immunoprecipitation, bimolecular fluorescence complementation, and immunofluorescence. Tumor-infiltrating immune cells were analyzed by flow cytometry. The HCC mouse model was established via hydrodynamic tail vein injection.
Results:
TM4SF1 was highly expressed in human HCC samples and murine models. Knockdown of TM4SF1 suppressed HCC proliferation both in vitro and in vivo, inducing non-secretory senescence through upregulation of p16 and p21. TM4SF1 enhanced the interaction between AKT1 and PDPK1, thereby promoting AKT phosphorylation, which subsequently downregulated p16 and p21. Meanwhile, TM4SF1-mediated AKT phosphorylation enhanced PD-L1 expression while reducing major histocompatibility complex class I level on tumor cells, leading to impaired cytotoxic function of CD8+ T cells and an increased proportion of exhausted CD8+ T cells. In clinical HCC samples, elevated TM4SF1 expression was associated with resistance to anti-PD-1 immunotherapy. Targeting TM4SF1 via adeno-associated virus induced tumor senescence, reduced tumor burden and synergistically enhanced the efficacy of anti-PD-1 therapy.
Conclusions
Our results revealed that TM4SF1 regulated tumor cell senescence and immune evasion through the AKT pathway, highlighting its potential as a therapeutic target in HCC, particularly in combination with first-line immunotherapy.
4.Targeting TM4SF1 promotes tumor senescence enhancing CD8+ T cell cytotoxic function in hepatocellular carcinoma
Weifeng ZENG ; Furong LIU ; Yachong LIU ; Ze ZHANG ; Haofan HU ; Shangwu NING ; Hongwei ZHANG ; Xiaoping CHEN ; Zhibin LIAO ; Zhanguo ZHANG
Clinical and Molecular Hepatology 2025;31(2):489-508
Background/Aims:
Transmembrane 4 L six family member 1 (TM4SF1) is highly expressed and contributes to the progression of various malignancies. However, how it modulates hepatocellular carcinoma (HCC) progression and senescence remains to be elucidated.
Methods:
TM4SF1 expression in HCC samples was evaluated using immunohistochemistry and flow cytometry. Cellular senescence was assessed through SA-β-gal activity assays and Western blot analysis. TM4SF1-related protein interactions were investigated using immunoprecipitation-mass spectrometry, co-immunoprecipitation, bimolecular fluorescence complementation, and immunofluorescence. Tumor-infiltrating immune cells were analyzed by flow cytometry. The HCC mouse model was established via hydrodynamic tail vein injection.
Results:
TM4SF1 was highly expressed in human HCC samples and murine models. Knockdown of TM4SF1 suppressed HCC proliferation both in vitro and in vivo, inducing non-secretory senescence through upregulation of p16 and p21. TM4SF1 enhanced the interaction between AKT1 and PDPK1, thereby promoting AKT phosphorylation, which subsequently downregulated p16 and p21. Meanwhile, TM4SF1-mediated AKT phosphorylation enhanced PD-L1 expression while reducing major histocompatibility complex class I level on tumor cells, leading to impaired cytotoxic function of CD8+ T cells and an increased proportion of exhausted CD8+ T cells. In clinical HCC samples, elevated TM4SF1 expression was associated with resistance to anti-PD-1 immunotherapy. Targeting TM4SF1 via adeno-associated virus induced tumor senescence, reduced tumor burden and synergistically enhanced the efficacy of anti-PD-1 therapy.
Conclusions
Our results revealed that TM4SF1 regulated tumor cell senescence and immune evasion through the AKT pathway, highlighting its potential as a therapeutic target in HCC, particularly in combination with first-line immunotherapy.
5.Application of fall prevention and management strategies based on patient participation and Internet plus in elderly inpatients
Lihua PENG ; Manping ZENG ; Xiaoping GUO ; Bingwen HE ; Xuhuan KUANG ; Yaling LIAO ; Xizhen LI
Chinese Journal of Practical Nursing 2024;40(7):487-494
Objective:To explore the effectiveness of patient participation and Internet plus in fall prevention management strategies of elderly inpatients and analyze the causes of falls, so as to provide a basis for continuous improvement in fall prevention to investigate their continuous improvement.Methods:A pre- and post-control study was conducted. Totally 8 480 elderly inpatients hospitalized in the Department of Internal Medicine from 1 June 2020 to 31 May 2021 in Chenzhou NO. 1 People′s Hospital were selected by convenient sampling as the control group, and 8 662 elderly inpatients hospitalized in the Department of Internal Medicine from 1 June 2021 to 31 May 2022 were in the experimental group. The routine fall prevention measures were used in the control group, and on this basis, the experimental group formulated and implemented fall prevention management strategies involving patients based on the patient participation framework "informing, participating, empowering, cooperating, and electronic information support" and introduced Internet plus. Then the differences between the two groups in terms of the incidence of falls and the satisfaction rate of nursing care were compared.Results:The experimental group included 8 662 cases (5 110 males and 3 552 females) with (73.96 ± 8.78) years old, while the control group included 8 480 cases (4 918 males and 3 562 females) with (74.11 ± 8.59) years old. The incidence of falls in experimental group (0.092%, 8/8 662) was lower than that in control group (0.224%, 19/8 480), and the difference was statistically significant ( χ 2=4.71, P<0.05); the nursing care satisfaction rate of experimental group (98.880%, 8 565/8 662) was higher than that of control group (96.450%, 8 179/8 480), and the difference also was statistically significant ( χ 2=106.50, P<0.01); the analysis of the fall causes of the patients revealed that the toilet squatting commode was an important hidden risk of falls in elderly patients. Conclusions:Fall prevention management strategies based on patient participation can reduce the incidence of falls in elderly patients and improve the satisfaction rate of nursing care. Patient participation introduced "Internet plus" can prevent patient falls. The root causes of patient falls will continue to change, and care managers should continually track real-time changes in the root causes of falls to identify problems, develop and adjust prevention strategies accordingly, and pay attention to the importance of infrastructure in the safety of older patients.
6.Efficacy and mechanism of static progressive stretch with different parameters in treatment of stiff knee in rats
Ke CHEN ; Xin ZHANG ; Kai REN ; Hui LIU ; Yingying LIAO ; Chenghong WEN ; Xiaoping SHUI
Chinese Journal of Orthopaedic Trauma 2024;26(3):255-261
Objective:To investigate the efficacy and mechanism of static progressive stretch (SPS) with different parameters in the treatment of stiff knee in rats.Methods:Fifty-six male 8-week SD rats were randomly divided into an operation group ( n=48) and a blank group ( n=8, normal feeding rats without any treatment). The knee joints of the rats in the operation group were fixed with Kirschner wire for 4 weeks to create models of right knee flexion stiffness. The 42 rats with successful modeling were randomly divided into 6 groups ( n=7): the model group was executed and sampled after successful modeling, the spontaneous recovery group was not given any treatment after successful modeling, group T1 was given SPS treatment for 20 min once per day, group T2 was given SPS treatment for 30 min once per day, group T3 was given SPS treatment for 20 min once every 2 days, and group T4 was given SPS treatment for 30 min once every 2 days. After 16 days, the range of knee motion, number of myofibroblasts, and positive proportion of transforming growth factor- β1 (TGF- β1) in the joint capsule were detected and compared between groups. Results:The ranges of knee motion in the spontaneous recovery group and the 4 SPS treatment groups were significantly greater than those before treatment ( P<0.05), and the improvements in the range of knee motion in the 4 SPS treatment groups were significantly greater than that in the spontaneous recovery group ( P<0.05). The range of knee motion in group T2 (112.29°±1.89°) was improved the most significantly. The number of myofibroblasts was (23.72±10.75)/HP, which was significantly smaller than that in T3 group [(55.72±33.56)/HP] or in T4 group [(50.72±33.34)/HP] ( P<0.05). The positive proportions of TGF- β1 in the joint capsule in the 4 SPS treatment groups were significantly lower than that in the model group, and the positive proportion of TGF- β1 in the joint capsule in group T2 (0.51%±0.38%) was significantly lower than those in group T3 and T4 ( P<0.05). Conclusions:As SPS treatment can reduce the expression of TGF- β1 in the joint and inhibit the excessive proliferation of myofibroblasts to alleviate the pathological changes in a stiff knee, it has a significant effect on the stiff knee in rats. The SPS treatment for 30 minutes and once per day may lead to the best efficacy.
7.National bloodstream infection bacterial resistance surveillance report (2022) : Gram-negative bacteria
Zhiying LIU ; Yunbo CHEN ; Jinru JI ; Chaoqun YING ; Qing YANG ; Haishen KONG ; Haifeng MAO ; Hui DING ; Pengpeng TIAN ; Jiangqin SONG ; Yongyun LIU ; Jiliang WANG ; Yan JIN ; Yuanyuan DAI ; Yizheng ZHOU ; Yan GENG ; Fenghong CHEN ; Lu WANG ; Yanyan LI ; Dan LIU ; Peng ZHANG ; Junmin CAO ; Xiaoyan LI ; Dijing SONG ; Xinhua QIANG ; Yanhong LI ; Qiuying ZHANG ; Guolin LIAO ; Ying HUANG ; Baohua ZHANG ; Liang GUO ; Aiyun LI ; Haiquan KANG ; Donghong HUANG ; Sijin MAN ; Zhuo LI ; Youdong YIN ; Kunpeng LIANG ; Haixin DONG ; Donghua LIU ; Hongyun XU ; Yinqiao DONG ; Rong XU ; Lin ZHENG ; Shuyan HU ; Jian LI ; Qiang LIU ; Liang LUAN ; Jilu SHEN ; Lixia ZHANG ; Bo QUAN ; Xiaoping YAN ; Xiaoyan QI ; Dengyan QIAO ; Weiping LIU ; Xiusan XIA ; Ling MENG ; Jinhua LIANG ; Ping SHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2024;17(1):42-57
Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System(BRICS)were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute(CLSI). WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period,9 035 strains of Gram-negative bacteria were collected from 51 hospitals,of which 7 895(87.4%)were Enterobacteriaceae and 1 140(12.6%)were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli( n=4 510,49.9%), Klebsiella pneumoniae( n=2 340,25.9%), Pseudomonas aeruginosa( n=534,5.9%), Acinetobacter baumannii complex( n=405,4.5%)and Enterobacter cloacae( n=327,3.6%). The ESBLs-producing rates in Escherichia coli, Klebsiella pneumoniae and Proteus spp. were 47.1%(2 095/4 452),21.0%(427/2 033)and 41.1%(58/141),respectively. The prevalence of carbapenem-resistant Escherichia coli(CREC)and carbapenem-resistant Klebsiella pneumoniae(CRKP)were 1.3%(58/4 510)and 13.1%(307/2 340);62.1%(36/58)and 9.8%(30/307)of CREC and CRKP were resistant to ceftazidime/avibactam combination,respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)complex was 59.5%(241/405),while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa(CRPA)was 18.4%(98/534). There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions,with statistically significant differences in the prevalence of CRKP and CRPA( χ2=20.489 and 20.252, P<0.001). The prevalence of CREC,CRKP,CRPA,CRAB,ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals( χ2=11.953,81.183,10.404,5.915,12.415 and 6.459, P<0.01 or <0.05),while the prevalence of CRPA was higher in economically developed regions(per capita GDP ≥ 92 059 Yuan)than that in economically less-developed regions(per capita GDP <92 059 Yuan)( χ2=6.240, P=0.012). Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend,and Escherichia coli is ranked in the top,while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different,and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.
8.Analysis of differentially expressed mRNA in gingival tissue of hypertensive rats with or without periodontitis based on next-generation sequencing
Zhiqing FENG ; Xiaoping SU ; Haiqing LIAO ; Renchuan TAO
Journal of Prevention and Treatment for Stomatological Diseases 2024;32(9):684-694
Objective To employ next-generation sequencing(NGS)to analyze differentially expressed mRNAs in the gingival tissue of hypertensive rats with or without periodontitis to provide a theoretical basis for the prevention and treatment of hypertension with periodontitis.Methods After obtaining approval from the Animal Experiment Ethics Committee,a hypertensive rat model was established by administering high-salt feed containing 8%(w/w)NaCl,and a periodontitis rat model was established by ligating the first molar of the mandibular region using 3-0 sterile silk thread.Rat models of the normal control(N),hypertension(H),and hypertension with periodontitis(PH)groups were estab-lished.The blood pressure,heart rate,alveolar bone resorption,and number of osteoclasts in the alveolar bone were measured,before harvesting the gingival tissues from the three groups for NGS to analyze the expression of significantly different genes.Gene ontology(GO)enrichment analysis was performed for all significantly differentially expressed genes between the H and PH groups.Kyoto Encyclopedia of Genes and Genomes(KEGG)enrichment analysis was per-formed.Key genes were screened by protein-protein interaction(PPI)networks,and the key gene expression in each group was verified using immunohistochemistry(IHC).The expression of key genes in the systemic circulation of each group was analyzed using enzyme-linked immunosorbent assay(ELISA).Results At the end of the experiment(11th week),the blood pressure was higher in both the H and PH groups than that in the N group(P<0.001),but there was no statistically significant difference in blood pressure between the H and PH groups.There was no statistical difference in heart rate among the 3 groups.Micro-CT showed that the distance from the cemento-enamel junction to the alveolar bone crest(CEJ-ABC)of the mandibular first molar in the PH group was significantly higher than that in the N and H groups(P<0.016 7).The number of osteoclasts in the alveolar bone of the PH group was significantly higher than that of the N and H groups(P<0.0167).No common differentially expressed genes were found among the 3 groups.There were 235 significantly differentially expressed genes in the gingival tissue between the H and PH groups,and 137 upreg-ulated genes(e.g.,P-selectin,keratin 16,and S100 calcium binding protein A)and 98 downregulated genes(e.g.,FK506 binding protein 5,mediator complex subunit 22,zinc finger and BTB domain containing 16)in the PH group compared to the H group.GO analysis showed that the major enriched biological processes(BP)were leukocyte migra-tion,the major cellular component(CC)was complex of collagen trimers,and the significant molecular function(MF)was extracellular matrix structural constituent in the H and PH groups.KEGG pathway analysis showed that signaling pathways such as cytokine-cytokine receptor interaction,IL-17 signaling pathway,and TNF-α signaling pathway were significantly enriched in the H and PH groups.PPI analysis identified four key genes affecting periodontitis in hyperten-sive conditions,including interleukin-1β(IL-1β),matrix metalloproteinase-9(MMP-9),collagen type Ⅰ alpha1(COL1α 1),and chemokine ligand 1(CXCL1).Compared to the N and H groups,the expressions of IL-1β and TNF-α were all upregulated in the gingival tissue and systemic serum in the PH group(P<0.016 7).Conclusion The differentially expressed mRNAs in hypertension with or without periodontitis included IL-1β and MMP-9,while the differentially ex-pressed signaling pathways were IL-17 and TNF-α.These results provide a theoretical reference for further investigation of the molecular regulatory mechanism of hypertension with periodontitis in the future.
9.The relationship between the Wnt signaling pathway and liver regeneration and its role in liver diseases
Yupei LIN ; Xiaoping LIU ; Yinbing LUO ; Feiyan LI ; Yingying LIAO ; Shicong MO ; Dewen MAO ; Yanmei LAN
Journal of Clinical Hepatology 2024;40(5):1050-1056
The Wnt signaling pathway plays an important role in maintaining liver homeostasis and liver regeneration.In healthy livers,the Wnt signaling pathway is mostly inactive,but it is continuously overactivated during cell renewal or regeneration processes,as well as in certain pathological conditions,diseases,precancerous states,and cancers.Persistent liver cell injury often leads to chronic liver diseases such as liver fibrosis,liver cirrhosis,and liver cancer.This article summarizes the basic structural features of the Wnt signaling pathway and analyzes its important role in the pathological progression of various liver diseases,so as to provide new ideas for the prevention and treatment of liver diseases in clinical practice.
10.National bloodstream infection bacterial resistance surveillance report(2022): Gram-positive bacteria
Chaoqun YING ; Yunbo CHEN ; Jinru JI ; Zhiying LIU ; Qing YANG ; Haishen KONG ; Haifeng MAO ; Hui DING ; Pengpeng TIAN ; Jiangqin SONG ; Yongyun LIU ; Jiliang WANG ; Yan JIN ; Yuanyuan DAI ; Yizheng ZHOU ; Yan GENG ; Fenghong CHEN ; Lu WANG ; Yanyan LI ; Dan LIU ; Peng ZHANG ; Junmin CAO ; Xiaoyan LI ; Dijing SONG ; Xinhua QIANG ; Yanhong LI ; Qiuying ZHANG ; Guolin LIAO ; Ying HUANG ; Baohua ZHANG ; Liang GUO ; Aiyun LI ; Haiquan KANG ; Donghong HUANG ; Sijin MAN ; Zhuo LI ; Youdong YIN ; Kunpeng LIANG ; Haixin DONG ; Donghua LIU ; Hongyun XU ; Yinqiao DONG ; Rong XU ; Lin ZHENG ; Shuyan HU ; Jian LI ; Qiang LIU ; Liang LUAN ; Jilu SHEN ; Lixia ZHANG ; Bo QUAN ; Xiaoping YAN ; Xiaoyan QI ; Dengyan QIAO ; Weiping LIU ; Xiusan XIA ; Ling MENG ; Jinhua LIANG ; Ping SHEN ; Yonghong XIAO
Chinese Journal of Clinical Infectious Diseases 2024;17(2):99-112
Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive bacteria from blood cultures in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System(BRICS)were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute(CLSI). WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units,and the top five bacteria were Staphylococcus aureus( n=1 147,36.3%),coagulase-negative Staphylococci( n=928,29.3%), Enterococcus faecalis( n=369,11.7%), Enterococcus faecium( n=296,9.4%)and alpha-hemolyticus Streptococci( n=192,6.1%). The detection rates of methicillin-resistant Staphylococcus aureus(MRSA)and methicillin-resistant coagulase-negative Staphylococci(MRCNS)were 26.4%(303/1 147)and 66.7%(619/928),respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome,rifampin,compound sulfamethoxazole,linezolid,minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%(2/369),and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions( χ2=14.578, P=0.002),while the detection rate of MRCNS in northern China was significantly higher than that in other regions( χ2=15.195, P=0.002). The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals( χ2=13.519 and 12.136, P<0.001). The detection rates of MRSA and MRCNS in economically more advanced regions(per capita GDP≥92 059 Yuan in 2022)were higher than those in economically less advanced regions(per capita GDP<92 059 Yuan)( χ2=9.969 and 7.606, P=0.002和0.006). Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China, Staphylococci is the most common while the MRSA incidence decreases continuously with time;the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China,with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.

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