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:This study aimed to validated the diagnostic accuracy of Global Leadership Initiative on Malnutrition(GLIM)criteria for malnutrition in pancreatic cancer patients undergoing pancreaticoduodenectomy and to evaluated its prognostic value for postoperative outcome.Methods:A retrospective analysis was conducted on 230 consecutive pancreatic cancer patients who underwent pancreaticoduodenectomy at the Department of Pancreatobiliary Surgery,Sun Yat-sen University Cancer Center,between January 2018 to January 2024.Patients were stratified into malnutrition group and non-malnutrition group using Nutritional Risk Screening 2002(NRS 2002)and GLIM criteria.Multivariable logistic regression identified independent risk factors for postoperative morbidity.Results:GLIM criteria identified malnutrition in 96 patients(41.7％).Compared with the non-malnourished group,the number of preoperative nutritional support(t=20.038,P<0.001),the number of preoperative enteral nutrition support(t=8.377,P=0.004),the number of preoperative parenteral nutrition support(t=22.302,P<0.001),the number of anemia(t=8.037,P=0.005)and preoperative parenteral nutrition use days(t=-2.898,P=0.009),the difference was statistically significant.There were statistically significant differences in C-reactive protein(t=10.944,P=0.008),NLR(t=-2.523,P=0.012)and PNI(t=-2.397,P=0.017)between the two groups before surgery.Preoperative BMI(t=-4.410,P<0.001)was significantly lower in the malnourished group.The number of postoperative parenteral nutrition days(Z=-2.283,P=0.022)and amino acid supplementation during postoperative hospitalization were significantly higher in the malnourished group(Z=-2.309,P=0.021).The incidence of malnutrition was higher in patients with Clavien-Dindo grade≥Ⅲ(P=0.030)and intra-abdominal infections(P=0.049).Multivariable analysis identified preoperative weight loss(OR=2.154,95％CI:1.158～4.005;P=0.015)and BMI reduction(OR=0.175,95％CI:0.040～0.775;P=0.022)as independent predictors of postoperative complications.Conclusions:The GLIM standard effectively characterize malnutrition status in pancreatic cancer patients after pancreaticoduodenectomy patients and demonstrate superior predictive performance for postoperative morbidity.It has good predictive performance and clinical application value.

With the rapid development of generative artificial intelligence(GAI)technologies,their widespread application in academic research and writing is continuously expanding the boundaries of sci-entific inquiry.However,this trend has also raised a series of ethical and regulatory challenges,inclu-ding issues related to authorship,content authenticity,citation accuracy,and accountability.In light of the growing involvement of AI in generating academic content,establishing an open,controllable,and trustworthy ethical governance framework has become a key task for safeguarding research integrity and maintaining trust within the academic community.This expert consensus outlines ethical requirements across key stages of AI-assisted academic writing-including topic selection,data management,citation practices,and authorship attribution.It aims to clarify the boundaries and ethical obligations surrounding AI use in academic writing,ensuring that technological tools enhance efficiency without compromising in-tegrity.The goal is to provide guidance and institutional support for building a responsible and sustainable research ecosystem.

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 By simulating the etiology of abnormal uterine bleeding-ovulatory dysfunction(AUB-O)and establishing a rat model of abnormal uterine bleeding(AUB),this study aims to provide an experimental platform for investigating pathological mechanisms and developing therapeutic drugs for AUB.Methods After acclimation,24 adult(10-week-old)female SD rats were randomly divided into a normal control group(6 rats)and a model group(18 rats).The normal control group was housed in a barrier environment,while the model group underwent bilateral ovariectomy via dorsal approach in the same environment and rested for one week before starting to receive modeling drugs.In the model group,from Days 1 to 3 of modeling,each rat received a daily subcutaneous injection of 0.5 mg estradiol into the dorsal region.From Days 4 to 7,a daily subcutaneous injection of 5.0 mg progesterone was administered.On Day 6,rats received bilateral injections of 0.5 mL soybean oil per uterine cavity(total 1.0 mL)via the same dorsal surgical incision.On Day 8,mifepristone(10 mg/kg)was administered via oral gavage.The estrous cycle stage and its dynamic changes were continuously monitored during modeling.Uterine bleeding was recorded during the 48-hour observation period post-modeling.Serum and uterine tissue samples were collected from the model group at 0,12,24,36,and 48 h after mifepristone administration,while the normal control group was sampled at 36 h.The samples were subjected to HE staining,serum sex hormone ELISA,immunohistochemistry,TUNEL apoptosis staining,Western blotting,transcriptome sequencing,and bioinformatics analysis for comprehensive evaluation of the AUB rat model.Results The AUB rats exhibited uterine bleeding,endometrial detachment and injury,incomplete uterine restoration,inflammatory cell infiltration in the endometrium,enhanced tissue apoptosis,and structural damage of the stroma,glands,and vasculature.Compared with the normal control group,the levels of serum follicle-stimulating hormone(FSH),estradiol,and luteinizing hormone(LH)were significantly increased in the AUB rats(P＜0.05).The vascular density of the endometrium was significantly reduced(P＜0.05).The expression of vascular endothelial growth factor(VEGF)was qualitatively observed to be markedly enhanced at the site of endometrial detachment but significantly decreased around the stromal blood vessels(P＜0.01).Matrix metalloproteinase-9(MMP-9)expression was qualitatively observed to be strongly upregulated at the site of endometrial injury but significantly reduced in the non-detached stroma and glands(P＜0.01).Endometrial stromal cell apoptosis was significantly enhanced(P＜0.01).The expression levels of fibroblast growth factor 2(FGF2)and endothelin-1(ET-1)in uterine tissues were significantly decreased(P＜0.05).After comparing the transcriptome sequencing results of uterine tissues between AUB and normal rats,a total of 4 723 differentially expressed genes were identified,including 2 191 up-regulated genes and 2 532 down-regulated genes.KEGG enrichment analysis revealed that these differentially expressed genes were significantly enriched in pathways related to inflammation,immune apoptosis,cell signal transduction,proliferation and differentiation,and muscle contraction,among others.Conclusion An AUB rat model can be successfully established using a sequential administration protocol of estrogen,progesterone,and mifepristone to simulate the etiology of AUB-O.In this model,endometrial injury is associated with inflammation and apoptosis,with pathological manifestations influenced by abnormal vasoconstriction and impaired endometrial regeneration.This rat model closely recapitulates pathological characteristics of non-structural AUB observed in clinical practice,making it a validated experimental platform for exploring the pathological mechanisms and therapeutic interventions of non-structural AUB.

Objective By simulating the etiology of abnormal uterine bleeding-ovulatory dysfunction(AUB-O)and establishing a rat model of abnormal uterine bleeding(AUB),this study aims to provide an experimental platform for investigating pathological mechanisms and developing therapeutic drugs for AUB.Methods After acclimation,24 adult(10-week-old)female SD rats were randomly divided into a normal control group(6 rats)and a model group(18 rats).The normal control group was housed in a barrier environment,while the model group underwent bilateral ovariectomy via dorsal approach in the same environment and rested for one week before starting to receive modeling drugs.In the model group,from Days 1 to 3 of modeling,each rat received a daily subcutaneous injection of 0.5 mg estradiol into the dorsal region.From Days 4 to 7,a daily subcutaneous injection of 5.0 mg progesterone was administered.On Day 6,rats received bilateral injections of 0.5 mL soybean oil per uterine cavity(total 1.0 mL)via the same dorsal surgical incision.On Day 8,mifepristone(10 mg/kg)was administered via oral gavage.The estrous cycle stage and its dynamic changes were continuously monitored during modeling.Uterine bleeding was recorded during the 48-hour observation period post-modeling.Serum and uterine tissue samples were collected from the model group at 0,12,24,36,and 48 h after mifepristone administration,while the normal control group was sampled at 36 h.The samples were subjected to HE staining,serum sex hormone ELISA,immunohistochemistry,TUNEL apoptosis staining,Western blotting,transcriptome sequencing,and bioinformatics analysis for comprehensive evaluation of the AUB rat model.Results The AUB rats exhibited uterine bleeding,endometrial detachment and injury,incomplete uterine restoration,inflammatory cell infiltration in the endometrium,enhanced tissue apoptosis,and structural damage of the stroma,glands,and vasculature.Compared with the normal control group,the levels of serum follicle-stimulating hormone(FSH),estradiol,and luteinizing hormone(LH)were significantly increased in the AUB rats(P＜0.05).The vascular density of the endometrium was significantly reduced(P＜0.05).The expression of vascular endothelial growth factor(VEGF)was qualitatively observed to be markedly enhanced at the site of endometrial detachment but significantly decreased around the stromal blood vessels(P＜0.01).Matrix metalloproteinase-9(MMP-9)expression was qualitatively observed to be strongly upregulated at the site of endometrial injury but significantly reduced in the non-detached stroma and glands(P＜0.01).Endometrial stromal cell apoptosis was significantly enhanced(P＜0.01).The expression levels of fibroblast growth factor 2(FGF2)and endothelin-1(ET-1)in uterine tissues were significantly decreased(P＜0.05).After comparing the transcriptome sequencing results of uterine tissues between AUB and normal rats,a total of 4 723 differentially expressed genes were identified,including 2 191 up-regulated genes and 2 532 down-regulated genes.KEGG enrichment analysis revealed that these differentially expressed genes were significantly enriched in pathways related to inflammation,immune apoptosis,cell signal transduction,proliferation and differentiation,and muscle contraction,among others.Conclusion An AUB rat model can be successfully established using a sequential administration protocol of estrogen,progesterone,and mifepristone to simulate the etiology of AUB-O.In this model,endometrial injury is associated with inflammation and apoptosis,with pathological manifestations influenced by abnormal vasoconstriction and impaired endometrial regeneration.This rat model closely recapitulates pathological characteristics of non-structural AUB observed in clinical practice,making it a validated experimental platform for exploring the pathological mechanisms and therapeutic interventions of non-structural AUB.

Objective To study the expression characteristics of osteoprotegerin(OPG)/receptor activator of nuclear factor-κB ligand(RANKL)/receptor activator of nuclear factor-κB(RANK)system and the relationship with fibrosis in myocardial tissues of rats with chronic heart failure.Methods SD rats were randomly divided into sham-operation group(12 rats)and model group.In sham-operation group,surgical thread was passed through the abdominal aorta without constricting it after laparotomy;in model group,establish the heart failure model by abdominal aorta coarctation.The successful model rats were randomly divided into model 1 week(12 rats),model 2 weeks(11 rats),model 4 weeks(11 rats),model 8 weeks(11 rats)and model 12 weeks groups(11 rats).The end point of the study is at week 12.The contents of hydroxyproline(HYP),total myocardial collagen and collagen volume fraction(CVF)were compaired in all proups.The expression levels of OPG,RANKL and RANK proteins in cardiomyocytes were determined by Western blot.Results The contents of HYP in sham-operation,model 1 week,model 2 weeks,model 4 weeks,model 8 weeks and model 12 weeks group were(0.25±0.04),(0.37±0.05),(0.45±0.04),(0.60±0.05),(0.82±0.10)and(1.03±0.07)μg·mg-1;the total myocardial collagen contents were(1.87±0.31),(2.73±0.38),(3.36±0.31),(4.47±0.37),(6.08±0.74)and(7.67±0.49)μg·mg-1;the CVF were(1.95±0.23)％,(2.40±0.25)％,(3.65±0.25)％,(5.43±0.29)％,(6.97±0.36)％and(9.38±0.49)％;the relative expression levels of OPG protein were 0.64±0.07,0.80±0.07,1.02±0.07,1.32±0.11,2.13±0.12 and 2.84±0.16;the relative expression levels of RANKL protein were 0.71±0.08,1.06±0.07,1.53±0.07,2.62±0.12,4.46±0.14 and 6.11±0.16;the relative expression levels of RANK protein were 0.30±0.05,0.45±0.05,0.63±0.06,0.98±0.07,1.43±0.10 and 1.63±0.10.With the extention of time,the above indexs of all model groups were significantly higher than those in the sham-operation group(all P＜0.05).There were positive linear correlation between the relative expression levels of OPG,RANKL,RANK protein and the levels of CVF and total contents in cardiomyocytes of rats with chronic heart failure(allP＜0.01).Conclusions In the process of chronic heart failure,the expression of OPG/RANKL/RANK axis is obviously enhanced,in which the up-regulation of RANKL level is most obvious.The expression level of OPG/RANKL/RANK is positively correlated with CVF and total myocardial collagen content.

Objective To understand the changing composition and antibiotic resistance of bacterial species in the clinical isolates from outpatient and emergency department(hereinafter referred to as outpatients)and inpatient children over time in various hospitals,and to provide laboratory evidence for rational antibiotic use.Methods The data on clinically isolated pathogenic bacteria and antimicrobial susceptibility of isolates from outpatients and inpatient children in the CHINET program from 2015 to 2021 were collected and analyzed.Results A total of 278 471 isolates were isolated from pediatric patients in the CHINET program from 2015 to 2021.About 17.1％of the strains were isolated from outpatients,primarily group A β-hemolytic Streptococcus,Escherichia coli,and Staphylococcus aureus.Most of the strains(82.9％)were isolated from inpatients,mainly SS.aureus,E.coli,and H.influenzae.The prevalence of methicillin-resistant S.aureus(MRSA)in outpatients(24.5％)was lower than that in inpatient children(31.5％).The MRSA isolates from outpatients showed lower resistance rates to the antibiotics tested than the strains isolated from inpatient children.The prevalence of vancomycin-resistant Enterococcus faecalis or E.faecium and penicillin-resistant S.pneumoniae was low in either outpatients or inpatient children.S.pneumoniae,β-hemolytic Streptococcus and S.viridans showed high resistance rates to erythromycin.The prevalence of erythromycin-resistant group A β-hemolytic Streptococcus was higher in outpatients than that in inpatient children.The prevalence of β-lactamase-producing H.influenzae showed an overall upward trend in children,but lower in outpatients(45.1％)than in inpatient children(59.4％).The prevalence of carbapenem-resistant Klebsiella pneumoniae(CRKpn),carbapenem-resistant Pseudomonas aeruginosa(CRPae)and carbapenem-resistant Acinetobacter baumannii(CRAba)was 14％,11.7％,47.8％in outpatients,but 24.2％,20.6％,and 52.8％in inpatient children,respectively.The prevalence of multidrug-resistant E.coli,K.pneumoniae,Proteus mirabilis,P.aeruginosa and A.baumannii strains was lower in outpatients than in inpatient children.The prevalence of fluoroquinolone-resistant E.coli,ESBLs-producing K.pneumoniae,ESBLs-producing P.mirabilis,carbapenem-resistant E.coli(CREco),CRKpn,and CRPae was lower in children in outpatients than in inpatient children,but the prevalence of CRAba in 2021 was higher than in inpatient children.Conclusions The distribution of clinical isolates from children is different between outpatients and inpatients.The prevalence of MRSA,ESBL,and CRO was higher in inpatient children than in outpatients.Antibiotics should be used rationally in clinical practice based on etiological diagnosis and antimicrobial susceptibility test results.Ongoing antimicrobial resistance surveillance and prevention and control of hospital infections are crucial to curbing bacterial resistance.

Objective To investigate the changing antibiotic resistance profiles of E.coli isolated from patients in the 52 hospitals participating in the CHINET program from 2015 to 2021.Methods Antimicrobial susceptibility was tested for clinical isolates of E.coli according to the unified protocol of CHINET program.WHONET 5.6 and SPSS 20.0 software were used for data analysis.Results Atotal of 289 760 nonduplicate clinical strains ofE.coli were isolated from 2015 to 2021,mainly from urine samples(44.7±3.2)％.The proportion of E.coli strains isolated from urine samples was higher in females than in males(59.0％vs 29.5％).The proportion of E.coli strains isolated from respiratory tract and cerebrospinal fluid samples was significantly higher in children than in adults(16.7％vs 7.8％,0.8％vs 0.1％,both P＜0.05).The isolates from internal medicine department accounted for the largest proportion(28.9±2.8)％with an increasing trend over years.Overall,the prevalence of ESBLs-producing E.coli and carbapenem resistant E.coli(CREco)was 55.9％and 1.8％,respectively during the 7-year period.The prevalence of ESBLs-producing E.coli was the highest in tertiary hospitals each year from 2015 to 2021 compared to secondary hospitals.The prevalence of CREco was higher in children's hospitals compared to secondary and tertiary hospitals each year from 2015 to 2021.The prevalence of ESBLs-producing E.coli in tertiary hospitals and children's hospitals and the prevalence of CREco in children's hospitals showed a decreasing trend over the 7-year period.The prevalence of CREco in secondary and tertiary hospitals increased slowly.Antibiotic resistance rates changed slowly from 2015 to 2021.Carbapenem drugs(imipenem,meropenem)were the most active drugs amongβ-lactams against E.coli(resistance rate≤2.1％).The resistance rates of E.coli to β-lactam/β-lactam inhibitor combinations(piperacillin-tazobactam,cefoperazone-sulbactam),aminoglycosides(amikacin),nitrofurantoin and fosfomycin(for urinary isolates only)were all less than 10％.The resistance rate of E.coli strains to antibiotics varied with the level of hospitals and the departments where the strains were isolated,especially for cefazolin and ciprofloxacin,to which the resistance rate of E.coli strains from children in non-ICU departments was significantly lower than that of the strains isolated from other departments(P＜0.05).The E.coli isolates from ICU showed higher resistance rate to most antimicrobial agents tested(excluding tigecycline)than the strains isolated from other departments.The E.coli strains isolated from tertiary hospitals showed higher resistance rates to the antimicrobial agents tested(excluding tigecycline,polymyxin B,cefepime and carbapenems)than the strains from secondary hospitals and children's hospitals.Conclusions E.coli is an important pathogen causing clinical infection.More than half of the clinical isolates produced ESBL.The prevalence of CREco is increasing in secondary and tertiary hospitals over the 7-year period even though the overall prevalence is still low.This is an issue of concern.