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 explore the correlation between psoas major index(PMI)in patients with diffuse large B-cell lymphoma(DLBCL)and prognosis after rituximab,cyclophosphamide,doxorubicin,vincristine,prednisone(R-CHOP)chemotherapy.Methods Totally 148 DLBCL patients who received R-CHOP chemotherapy were retrospectively enrolled.Based on axis CT image at L3 vertebral transverse process,bilateral psoas muscles were delineated,and PMI was calculated.Then the patients were divided into muscle reduction group(≤lower quartile,n=37)and control group(＞lower quartile,n=111)according to the lower quartile of PMI.Clinical and imaging data were compared between groups,and the correlations of PMI with the above indexes were analyzed.The impact factors of prognosis of DLBCL were observed.Results Significant differences of body mass index(BMI),Eastern Cooperative Oncology Group(ECOG)score,international prognostic index(IPI),the proportion of B symptoms,mortality rate,3-year survival rate,β2-microglobulin,hemoglobin,albumin and PMI were found between groups(all P＜0.05).PMI of DLBCL patient was negatively correlated with age,ECOG score,IPI,β2-microglobulin and lactate dehydrogenase(LDH)(r=—0.126,-0.225,—0.262,—0.232,—0.229,all P＜0.05),but positively correlated with BMI and hemoglobin(r=0.282,0.376,both P＜0.05).The age,ECOG score,IPI and PMI were all independent impact factors of overall survival in DLBCL patients(all P＜0.05).Conclusion PMI was an independent impact factor of prognosis of DLBCL after R-CHOP chemotherapy.

Background: and Purpose Ruptured intracranial aneurysms (RIA) are associated with a mortality rate of up to 40% in the Chinese population, highlighting the critical need for targeted treatment interventions for at-risk individuals. Although the impact of aldehyde dehydrogenase 2 (ALDH2) gene mutations on susceptibility to intracranial aneurysms (IA) is well documented, the potential connection between ALDH2 rs671 single-nucleotide polymorphism (SNP) and RIA remains unexplored. Given the increased prevalence of ALDH2 gene mutations among Chinese Han individuals, it is clinically relevant to investigate the link between ALDH2 rs671 SNP and IA rupture. Methods: A prospective study was conducted on 546 patients diagnosed with IA to investigate the association between ALDH2 rs671 SNP and the risk of IA rupture. Results: The ALDH2 rs671 SNP (ALDH2*2) was significantly more prevalent in patients with unruptured IA (UIA) than in those with RIA (32.56% vs. 18.58%, P=0.004). Multivariate logistic regression analysis revealed that people with the ALDH2 mutation (ALDH2*1/*2 and ALDH2*2/*2 gene type) had a significantly reduced odds ratio (OR=0.49; 95% confidence level [CI] 0.27–0.88; P=0.018) for RIAs. Age-specific subgroup analysis indicated that the ALDH2 mutation provided a stronger protective effect in individuals aged 60 years and above with IA compared to those under 60 years old (OR=0.38 vs. OR=0.52, both P<0.05). Conclusion The incidence of RIA was significantly higher in individuals with a normal ALDH2 gene (ALDH2*1/*1) than in those with an ALDH2 rs671 SNP (ALDH2*1/*2 or ALDH2*2/*2). ALDH2 rs671 SNP may serve as a protective factor against RIA in the Chinese Han population.

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 To explore the characteristics of oropharyngeal metabolites of postoperative pneumonia(POP)and non-POP patients with gastric cancer by non-targeted metabolomics,and to provide reference for revea-ling the pathogenesis as well as clinical prevention and control.Methods Oropharyngeal swabs were collected from patients who underwent surgical treatment for gastric cancer in the department of gastrointestinal surgery of a tertia-ry hospital in Fujian Province from January 2022 to December 2023,nested case-control study was adopted,with 30 cases in POP group and non-POP group,respectively,ultrahigh performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)technique was adopted for detection,and multivariate statistical analysis was per-formed.Results The metabolites of POP group and non-POP group preoperatively,POP group and non-POP group postoperatively,POP group preoperatively and postoperatively,as well as non-POP group preoperatively and post-operatively did not show a clear trend of separation on the score graph of principal component analysis(PCA),par-tial least squares discriminant analysis(PLS-DA),and orthogonal partial least squares discriminant analysis(OPLS-DA),but the screening of the differential metabolites revealed that the relative abundances of ascorbic acid and lipoic acid in the POP group preoperatively were lower than non-POP group preoperatively.The relative abundance of 5'-adenylic acid in the POP group preoperatively was lower than postoperatively,while the relative abundances of suc-cinic acid and phenylacetaldehyde were higher.There were differences in metabolic pathways such as phenylalanine.Conclusion Alteration of metabolite level due to abnormalities in specific metabolic pathways presents in the deve-lopment of gastric cancer POP and may be related to the development of POP.

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 investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.

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.