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.

Ursodeoxycholic acid(UDCA)is a naturally occurring,low-toxicity,and hydrophilic bile acid(BA)in the human body that is converted by intestinal flora using primary BA.Solute carrier family 7 member 11(SLC7A11)functions to uptake extracellular cystine in exchange for glutamate,and is highly expressed in a variety of human cancers.Retroperitoneal liposarcoma(RLPS)refers to liposarcoma originating from the retroperitoneal area.Lipidomics analysis revealed that UDCA was one of the most significantly down-regulated metabolites in sera of RIPS patients compared with healthy subjects.The augmentation of UDCA concentration(≥25 μg/mL)demonstrated a suppressive effect on the proliferation of liposarcoma cells.[15N2]-cystine and[13Cs]-glutamine isotope tracing revealed that UDCA impairs cystine uptake and glutathione(GSH)synthesis.Mechanistically,UDCA binds to the cystine transporter SLC7A11 to inhibit cystine uptake and impair GSH de novo synthesis,leading to reactive oxygen species(ROS)accumulation and mitochondrial oxidative damage.Furthermore,UDCA can promote the anti-cancer effects of ferroptosis inducers(Erastin,RSL3),the murine double minute 2(MDM2)inhibitors(Nutlin 3a,RG7112),cyclin dependent kinase 4(CDK4)inhibitor(Abemaciclib),and glutaminase inhibitor(CB839).Together,UDCA functions as a cystine exchange factor that binds to SLC7A11 for antitumor activity,and SLC7A11 is not only a new transporter for BA but also a clinically applicable target for UDCA.More importantly,in combination with other antitumor chemotherapy or physiotherapy treatments,UDCA may provide effective and promising treatment strategies for RLPS or other types of tumors in a ROS-dependent manner.

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 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 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.

Objective Advances in synthetic DNA technology have made it much easier to fake human DNA samples.There are literature reports that fake human DNA can be synthesized by different methods and implanted in the field to confuse the investigation or mislead the trial.Therefore,distinguishing authentic human DNA from synthetic DNA and performing individual identification has become a critical scientific challenge.Methods We define a novel composite genetic marker(methylation-microhaplotype)by combining CpG sites stably hypermethylated or hypomethylated in natural human DNA and nearby immediately adjacent microhaplotype sites.A total of 19 locis were obtained according to the screening criteria,and a composite detection system for methylation-microhaplotypes was established using MPS technology.Random volunteer DNA samples were extracted and synthetic DNA samples were prepared based on whole genome amplification techniques.Population DNA samples were analyzed to evaluate forensic parameters and methylation variability of the methylation-microhaplotype markers.Comparative analyses of human and synthetic DNA were conducted to assess the markers'ability to discriminate between the two and to detect/type both components in mixed mixed samples.Results The composite detection system composed of 19 locis demonstrated high individual identification ability,achieving a cumulative individual identification probability of 0.999 999 999 996 86.12 hypermethylated locis and 7 hypomethylated locis had relatively stable methylation levels in 57 human DNA samples.According to the allele methylation rate(Ram)value,the system can effectively identify natural and synthetic DNA samples.Meanwhile,for mixed DNA samples,the presence of human and synthetic DNA samples can be found and genotyped.Conclusion Methylation-microhaplotype genetic markers,which can discover human DNA and synthetic DNA and can detect the presence and genotyping of them from mixed samples,is a potential useful tool for forensic DNA analysis.

Objective:To explore the improvement effect of Tiaojing Zhuyun formula combined with Dai meridian moxibustion on endometrial fibrosis in rats with intrauterine adhesions(IUA)by regulating M2 type macrophage polarization.Methods:SD rats were selected to establish an IUA model using a dual injury method of mechanical curettage and lipopolysaccharide infection,which were randomly separated into model group,Tiaojing Zhuyun formula group,Dai meridian moxibustion group,Tiaojing Zhuyun formula+Dai meridian moxibustion group and Bujiale group,with 10 rats in each group,another 10 rats were regarded as a sham operation(control)group,after grouping and treatment,the number of embryo implantation of rats in each group after cage closure was detected;HE staining was applied to detect pathological morphology of uterine tissue in rats in different groups,and their endometrial thickness and glandular number were compared;Masson staining was applied to detect endometrial fibrosis in rats of each group,and the collagen volume fraction(CVF)was compared;ELISA was applied to detect serum levels of profibrotic factor TGF-β1,pro-inflammatory factors IL-1β and IL-6,and levels of procollagen type Ⅰ carboxy-terminal peptide(PⅠNP)and procollagen Ⅲ N-terminal peptide(PⅢNP)of rats in each group;immunofluorescence staining was applied to detect expressions of M2 type macrophage markers CD163 and CD68 in endometrium of rats in each group.Results:Compared with control group,model group showed obvious pathological damage to uterine tissue,thickness of endometrium was thinner,the number of glands and embryo implantation were obviously reduced(P<0.05),endometrial CVF,levels of serum PⅠNP,P Ⅲ NP,TGF-β1,IL-1β and IL-6,and the number of CD163 and CD68 positive cells in endometrium were increased(P<0.05);compared with model group,pathological damage to uterine tissue of rats in Tiaojing Zhuyun formula group,Dai meridian moxibustion group,Tiaojing Zhuyun formula+Dai meridian moxibustion group and Bujiale group was reduced,thickness of endometrium,the number of glands and embryo implantation,and the numbers of CD163 and CD68 positive cells in endometrium were increased(P<0.05),endometrial CVF and levels of serum PⅠNP,P Ⅲ NP,TGF-β1,IL-1β and IL-6 were reduced(P<0.05);compared with Tiaojing Zhuyun formula group and Dai meridian moxibustion group,pathological damage to uterine tissue of rats in Tiaojing Zhuyun formula+Dai meridian moxibustion group and Bujiale group was alleviated,thickness of endometrium,the number of glands and embryo implantation,and the number of CD163 and CD68 positive cells in endometrium were increased(P<0.05),endometrial CVF and levels of serum PⅠNP,P Ⅲ NP,TGF-β1,IL-1β and IL-6 were reduced(P<0.05);there was no obvious change in all indicators between Tiaojing Zhuyun formula+Dai meridian moxibustion group and Bujiale group(P>0.05).Conclusion:Combination of Tiaojing Zhuyun formula and Dai meridian moxibustion can promote the polarization of M2 type macrophages,thereby inhibiting inflammation and endometrial fibrosis in IUA rats,and improving their symptoms of uterine adhesions.

Objective:To investigate the interventional effect of Rhizoma Corydalis on mice with ulcerative colitis(UC)induced by dextran sulfate sodium(DSS),as well as the potential mechanism of Rhizoma Corydalis in the treatment of UC based on metabolomics and inflammation biomarkers.Methods:A mouse model of UC was established,and then the mice were divided into model group,high-dose group(1.517 g/kg crude drug),middle-dose group(0.986 g/kg crude drug),low-dose group(0.455 g/kg crude drug),and positive drug group(5-aminosalicylic acid at a dose of 718.8 mg/kg),while the mice without modeling were selected as normal group(0.9%NaCl by gavage).The mice in each group were administered for 7 consecutive days,and phenotypic parameters were dynamically moni-tored,such as body weight change,disease activity index(DAI),mean daily food intake,and daily water intake.The mice were sacri-ficed after 7 days to collect serum and colon tissue samples;ELISA was used to measure the serum levels of the proinflammatory fac-tors interleukin-6(IL-6),interleukin-17A(IL-17A),C-reactive protein(CRP),and tumor necrosis factor-α(TNF-α),and ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF/MS)was used to perform the non-targeted metabolomics analysis and compare the differences in se-rum metabolite profiles between groups.The mice were selected for modeling and validation with the same method,and glutathione(GSH)was selected as the positive drug.Colon length and mucosal damage were assessed,and quantitative real-time PCR was used to measure the relative mRNA expression levels of the key genes in the glutathione synthesis pathway(γ-glutamylcysteine synthetase[γ-GCS]and oxidative stress regulators yap1p and skn7)and mito-chondrial GSH transporter protein(Slc25a39)in colonic tissue.Results:Rhizoma Corydalis significantly improved weight loss,DAI,and colon length in a dose-dependent manner in the model animals,and there were reductions in the serum levels of IL-6,CRP,and TNF-α,while it had no significant effect on IL-17A.The metabolomics analysis revealed 21 potential biomarkers associated with amino acid and lipid metabolism,which were significantly regulated by Rhizoma Corydalis.In the verification experiment,both Rhi-zoma Corydalis and GSH exerted a significant protective effect against colonic mucosal damage without affecting colon length.Rhizoma Corydalis upregulated the expression of genes associated with glutathione synthesis,especially γ-GCS,suggesting that Rhizoma Co-rydalis could enhance intestinal antioxidant defenses.Conclusion:Rhizoma Corydalis has a therapeutic potential in a mouse model of DSS-induced UC and can alleviate symptoms,reduce the serum levels of inflammatory markers,and regulate metabolic pathways,and upregulation of the genes associated with glutathione synthesis suggests that the drug can enhance intestinal antioxidant defenses.