Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

Objective Based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses(PRISMA)guidelines,to obtain precise and reliable comprehensive effect conclusions by quantitatively combining pharmacodynamic results from animal experiments investigating Astragali Radix(single-entity Astragali Radix preparation)or its ingredients for treatment of acute pancreatitis(AP)in literature reports through meta-analysis.Methods Databases including China National Knowledge Infrastructure(CNKI),VIP Database for Chinese Technical Periodicals(VIP),Wanfang Data Knowledge Service Platform,China Biomedical Literature Database(CBMdisc),PubMed,and Web of Science(WOS)were searched from inception to March 2025 for animal studies related to Astragali Radix(single-entity Astragali Radix preparation)or its ingredients for AP treatment.Risk of bias for included studies was assessed with SYRCLE tool.Heterogeneity among studies was evaluated according to Cochrane Handbook using Cochrane's Qtest and/2statistic.Sensitivity analysis was performed using the leave-one-out method,and publication bias risk was detected using Egger's test.Results A total of 297 articles were retrieved,and after screening and evaluation,19 animal studies were finally included for meta-analysis.These 19 publications cover SD rats,as well as three breeds of mice:C57BL/6 mice,BALB/c mice,and Kunming mice.SYRCLE scores ranged from 3 to 4.The results of the sensitivity analysis showed that no study significantly affected the heterogeneity index.The results of Egger's test showed a significant publication bias with P＜0.05.Cochrane's Qtest and I2statistic indicated substantial heterogeneity among studies.Meta-analysis results of 19 animal studies showed that single-entity Astragali Radix preparation(Astragali Radix injection)could reduce serum amylase(AMY)levels,an AP-specific indicator.The Astragali Radix ingredients could decrease both AMY and lipase(LPS)levels.Astragali Radix injection or its ingredients could reduce serum levels of tumor necrosis factor-α(TNF-α),interleukin(IL)-6,and IL-1 β,while increasing IL-10 levels;could increase serum levels of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px),and decrease malondialdehyde(MDA)levels.High-dose groups of Astragali Radix injection or Astragali Radix ingredients were more effective than low-dose groups in reducing AMY,TNF-α,and IL-6 levels and increasing SOD levels,but dosage effect on MDA levels was not demonstrated.Conclusion Evidence-based analysis of animal experiment results shows that in various animal models including SD rats,C57BL/6 mice,BALB/c mice,and Kunming mice,Astragali Radix injection or its ingredients can effectively reduce expression or secretion levels of AP-specific indicators(AMY and LPS).The mechanisms may be related to some inflammatory mediators,including reducing TNF-α,IL-6,and IL-1 β levels and increasing IL-10 levels;They may also intervene in oxidative/antioxidative equilibrium,such as increasing SOD and GSH-Px levels and reducing MDA levels.Except for MDA,dose-response relationships are shown for reducing AMY,TNF-α,and IL-6 levels and increasing SOD levels with Astragali Radix injection or its ingredients.However,due to high heterogeneity,potential publication bias risk,and species differences between animal models and human diseases in existing studies,further high-quality clinical trials or animal experiments are still needed in the future.

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.

Objective Based on the Preferred Reporting Items for Systematic reviews and Meta-Analyses(PRISMA)guidelines,to obtain precise and reliable comprehensive effect conclusions by quantitatively combining pharmacodynamic results from animal experiments investigating Astragali Radix(single-entity Astragali Radix preparation)or its ingredients for treatment of acute pancreatitis(AP)in literature reports through meta-analysis.Methods Databases including China National Knowledge Infrastructure(CNKI),VIP Database for Chinese Technical Periodicals(VIP),Wanfang Data Knowledge Service Platform,China Biomedical Literature Database(CBMdisc),PubMed,and Web of Science(WOS)were searched from inception to March 2025 for animal studies related to Astragali Radix(single-entity Astragali Radix preparation)or its ingredients for AP treatment.Risk of bias for included studies was assessed with SYRCLE tool.Heterogeneity among studies was evaluated according to Cochrane Handbook using Cochrane's Qtest and/2statistic.Sensitivity analysis was performed using the leave-one-out method,and publication bias risk was detected using Egger's test.Results A total of 297 articles were retrieved,and after screening and evaluation,19 animal studies were finally included for meta-analysis.These 19 publications cover SD rats,as well as three breeds of mice:C57BL/6 mice,BALB/c mice,and Kunming mice.SYRCLE scores ranged from 3 to 4.The results of the sensitivity analysis showed that no study significantly affected the heterogeneity index.The results of Egger's test showed a significant publication bias with P＜0.05.Cochrane's Qtest and I2statistic indicated substantial heterogeneity among studies.Meta-analysis results of 19 animal studies showed that single-entity Astragali Radix preparation(Astragali Radix injection)could reduce serum amylase(AMY)levels,an AP-specific indicator.The Astragali Radix ingredients could decrease both AMY and lipase(LPS)levels.Astragali Radix injection or its ingredients could reduce serum levels of tumor necrosis factor-α(TNF-α),interleukin(IL)-6,and IL-1 β,while increasing IL-10 levels;could increase serum levels of superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px),and decrease malondialdehyde(MDA)levels.High-dose groups of Astragali Radix injection or Astragali Radix ingredients were more effective than low-dose groups in reducing AMY,TNF-α,and IL-6 levels and increasing SOD levels,but dosage effect on MDA levels was not demonstrated.Conclusion Evidence-based analysis of animal experiment results shows that in various animal models including SD rats,C57BL/6 mice,BALB/c mice,and Kunming mice,Astragali Radix injection or its ingredients can effectively reduce expression or secretion levels of AP-specific indicators(AMY and LPS).The mechanisms may be related to some inflammatory mediators,including reducing TNF-α,IL-6,and IL-1 β levels and increasing IL-10 levels;They may also intervene in oxidative/antioxidative equilibrium,such as increasing SOD and GSH-Px levels and reducing MDA levels.Except for MDA,dose-response relationships are shown for reducing AMY,TNF-α,and IL-6 levels and increasing SOD levels with Astragali Radix injection or its ingredients.However,due to high heterogeneity,potential publication bias risk,and species differences between animal models and human diseases in existing studies,further high-quality clinical trials or animal experiments are still needed in the future.

Objective To investigate the effects of extracellular vesicles(EVs)derived from synovial fluid of rheumatoid arthritis(RA)patients on angiogenesis of human umbilical vein endothelial cells,and to preliminarily explore the underlying mechanisms.Methods Synovial fluid samples of knee joint were collected from 20 patients with RA and 20 patients with osteoarthritis(OA)in this study.EVs were purified using ultracentrifugation.The morphology and size of EVs were observed by transmission electron microscopy and nanoparticle tracking analysis.CD9,CD63,cytochrome c(Cyt-c),vascular endothelial growth factor(VEGF),lysyl oxidase(LOX),matrix metalloproteinase 2(MMP2),tumour necrosis factor alpha(TNF-α),transforming growth factor beta1(TGF-β1)in EVs were detected using Western blot.Human umbilical vein endothelial cells(HUVEC)were treated with the EVs.The growth,migration and angiogenesis of HUVEC were observed by CCK8 assay,TranswellTM chamber assay,scratch test and matrigel angiogenesis assay,respectively.The effect of EVs on the PI3K/AKT pathway in HUVEC was assessed using Western blot.Results Both EVs from RA synovial fluid(RA-EVs)and OA synovial fluid(OA-EVs)were cup-shaped,mainly between 30-400 nm in diameter,expressing CD63 and CD9,but not Cyt-c.RA-EVs carried more VEGF,LOX,MMP2,TNF-α and TGF-β1 than OA-EVs.Compared with the OA-EVs intervention,RA-EVs significantly promoted the proliferation,migration,and angiogenesis of HUVECs,as well as upregulated PI3K/AKT phosphorylation.The inhibitor of PI3K suppressed angiogenesis induced by EVs.Conclusion EVs in synovial fluid of RA carried more cytokines and enzymes that related angiogenesis and inflammation.These EVs exert their pro-angiogenic effects by activating the PI3K/AKT pathway,then contributing to the pathological progression of RA.

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.

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.

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.

Objective To establish an animal model of hand,foot,and mouth disease(HFMD)in Syrian hamsters coinfected with coxsackievirus A6(CVA6)and coxsackievirus B1(CVB1).Methods 42 Syrian hamsters were divided into a CVA6 infection group,CVB1 infection group,CVA6 and CVB1 coinfection group and control group.A HFMD model was established by nasal instillation of virus solution and phosphate-buffered saline.Clinical and physiological indicators and detoxification status were monitored and recorded for 15 d,and animals were selected on day 7(D7)after infection for histopathology and viral antigen and nucleic acid testing.Results Hamsters in the single-infection and coinfection groups showed clinical symptoms similar to human HFMD.White blood cell,neutrophil,and lymphocyte result were characteristic of viral infection.Both viral nucleic acids were detected in throat swabs,feces,blood,and tissues and both viruses were isolated from fecal samples.Pathological damage and positive co-localization of CVA6 and CVB1 viral antigen proteins and nucleic acids were found in brain and other tissues.Conclusions Nasal instillation of a CVA6 and CVB1 mixture can successfully coinfect Syrian hamsters,replicate herpes infection similar to human HFMD,and cause pathological viral myocarditis and encephalitis damage.The result showed that the coinfection group was more seriously affected than the single-infection group,with worse clinical symptoms,increased viral replication,and obvious tissue pathological damage.This study provides a reference for further basic and clinical research into human enterovirus coinfection.