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.

Objectives:To investigate the impact of the Micra AV leadless pacemaker on cardiac function.Methods:A total of 76 patients who received the implantation of Micra AV leadless pacemaker due to sick sinus syndrome or atrioventricular block at Ruijin Hospital,Shanghai Jiao Tong University School of Medicine from September 2022 to April 2023 were included in this study.Among them,26 patients(34.2%)had sick sinus syndrome,and 50 patients(65.8%)had atrioventricular block.The patients were followed up for 1 year postoperatively.Cardiac function was evaluated by echocardiography,and the parameters of the pacemaker were collected through the outpatient clinic programming system.Results:After a follow-up of 120(87,181)days,compared with the preoperative state,the left ventricular ejection fraction(LVEF)decreased postoperatively([66.6±5.6]%vs.[63.8±5.2]%,P<0.001),and the cardiac output increased[(4.3±1.2)L/min vs.(5.3±1.5)L/min,P<0.001].There were no statistically significant differences in various cardiac function indexes of patients with sick sinus syndrome between the postoperative and preoperative states(all P>0.05).Compared with the preoperative state,in patients with atrioventricular block,the LVEF decreased postoperatively([67.0±5.1]%vs.[63.4±4.4]%,P<0.001),the cardiac output increased([4.2±1.1]L/min vs.[5.2±1.2]L/min,P<0.001),and the left ventricular end-diastolic diameter decreased[(49.9±5.4)mm vs.(48.6±5.0)mm,P=0.044].Firth's logistic regression analysis indicated that the preoperative LVEF(for every 1%increase,OR=1.56,95%CI:1.12-2.17,P=0.001),stroke volume(for every 1 ml increase,OR=1.15,95%CI:1.04-1.28,P=0.001),body mass index(for every 1 kg/m2 increase,OR=1.49,95%CI:1.02-2.17,P=0.020),and hypertension(OR=12.71,95%CI:1.11-145.13,P=0.039)were independent risk factors for the decrease in LVEF after surgery in patients with atrioventricular block.After the implantation of the MciraTM AV leadless pacemaker,the overall atrioventricular synchrony rate was 81.2%(68.8%,89.0%).The atrioventricular synchrony rates of patients with sick sinus syndrome and those with atrioventricular block were 70.6%(59.5%,83.4%)and 82.4%(74.2%,89.3%)respectively(P<0.05).Firth's logistic regression analysis indicated that sick sinus syndrome(OR=0.26,95%CI:0.07-0.89,P=0.029)and preoperative LVEF(for every 1%increase,OR=1.18,95%CI:1.03-1.35,P=0.015)were independent predictive factors for the atrioventricular synchrony rate>80%.Conclusions:There are differences in the impacts of the Micra AV leadless pacemaker on the LVEF and atrioventricular synchrony rate between patients with sick sinus syndrome and those with atrioventricular block.The preoperative LVEF,stroke volume,body mass index,and hypertension have independent predictive effects on the decrease in postoperative LVEF in patients with atrioventricular block.Sick sinus syndrome and preoperative LVEF are independent predictive factors for the atrioventricular synchrony rate>80%after surgery.

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.

AIM:To investigate the regulatory role and molecular mechanisms of the p62-NIMA(never in mi-tosis gene A)-related kinase 7(NEK7)-gasdermin D(GSDMD)-mediated pyroptosis axis in a mouse model of gouty arthri-tis.METHODS:C57BL/6 mice were randomly divided into control group,model group,and colchicine group(n=5 per group).Conditional knockout mouse models of p62,GSDMD,and p62-GSDMD were constructed and assigned to p62-/-group,GSDMD-/-group,and p62-/--GSDMD-/-group,respectively(n=5 per group).The gouty arthritis model was in-duced by monosodium urate crystal injection into the ankle joint in all groups except control.The colchicine group re-ceived oral colchicine pretreatment for 3 days prior to MSU injection,continuing for 5 days total.Ankle joint swelling was measured using a vernier caliper at 0,6,12,24,and 48 hours post-injection.Serum levels of p62,GSDMD,caspase-1,interleukin-1β(IL-1β),and IL-18 were quantified by ELISA.Immunohistochemistry staining was performed to assess nu-cleotide-binding oligomerization domain-like receptor protein 3(NLRP3),apoptosis-associated speck-like protein contain-ing a caspase recruitment domain(ASC),cleaved caspase-1,and IL-1β expression in joint tissues.Western blot was con-ducted to detect protein expression of p62,GSDMD,NLRP3,ASC,cleaved caspase-1,and IL-1β in mouse ankle joints,while RT-qPCR was used to measure mRNA expression of p62,NEK7,GSDMD,NLRP3,caspase-1 and IL-1β.RE-SULTS:Serum p62 levels and p62 protein and mRNA expression in ankle joints were significantly elevated in the model group.Following p62 gene knockout,the protein expression of NLRP3,ASC,caspase-1,and IL-1β in ankle joints showed a marked increase.Both GSDMD-/-and p62-/--GSDMD-/-groups exhibited attenuated ankle joint swelling,reduced serum levels of caspase-1,IL-1β,and IL-18,along with downregulated expression of p62,NLRP3,ASC,caspase-1,and IL-1β at both mRNA and protein levels in ankle joints.The NEK7 mRNA expression was similarly suppressed in these groups.CONCLUSION:Our findings demonstrate that MSU crystals activate macrophages through the coordinated action of p62,NEK7,and GSDMD,triggering NLRP3 inflammasome-mediated pyroptosis and ultimately promoting joint inflammation in gout mice.The p62-NEK7-GSDMD axis represents a critical regulatory mechanism in the canonical pyrop-tosis signaling pathway.

Objective To establish a reliable Pseudomonas aeruginosa(PA)-induced sepsis model,providing an effective experimental method for investigating the pathogenicity,antibiotic resistance mechanism and infection-related inflammatory pathways of PA.Methods PA ATCC 27853 was selected as experimental strain.Different concentrations of bacterial suspension were applied to the surface of erector spinae muscle in mice.Echocardiography was performed 24 h after infection to examine cardiac function.Heart,lung,kidney tissue and blood samples were collected.Serum creatinine(Cr),blood urea nitrogen(BUN),inflammatory factors,and cardiac troponin Ⅰ(CTNI)were detected.The pathological changes in the heart,lung,and kidney tissues were observed.Results The survival rates of the 107 CFU/mL group,108 CFU/mL,109 CFU/mL,and 1010 CFU/mL groups were 100%,93.3%,73.3%,and 26.7%,respectively.The concentration of interleukin-6(IL-6)in the PA-infected group was significantly higher than that in the non-infected group.The concentration of tumor necrosis factor-α(TNF-α)in 108 CFU/mL group and 109 CFU/mL group were significantly higher than that in the non-infected group.The left ventricular ejection fraction(LVEF)of 108 CFU/mL and 109 CFU/mL groups decreased significantly compared to the non-infected group,and the CTNI level increased significantly in infected group compared to the non-infected group.Compared with the non-infected group,only the 109 CFU/mL group showed significant statistical differences in Cr and BUN levels,while no significant differences were observed in the other PA-infected groups.The results of histopathology showed that the heart,lung,and kidney tissues of mice in the 109 CFU/mL group were significantly infiltrated by inflammatory cells,with obvious edema of tissue cells,disordered structural arrangement,thickening of alveolar septa,and renal interstitial stenosis.Conclusion The experiment successfully established a sepsis model induced by PA with a bacterial concentration of 109 CFU/mL,which is stable and reliable,and can provide a model basis for exploring sepsis and PA infection diseases.

The left maxilla of a patient was resected because of tumor,and the defect was reconstruted with fibular transplantation.The autonomous dental implant robot technology was used to achieve precise implantation of multiple implants and immediate denture restoration within the limited left maxilla.The surgery was minimally invasive and efficient,and significantly reducing patient post-operative discomfort.The final restoration was completed 6 months after surgery.

Objective:To understand the usage situation of e-cigarettes among residents aged 18-65 in Beijing, explore the relationship between e-cigarette use and cigarette smoking as well as smoking cessation behaviors, and provide scientific support for the developing and improving policies and measures related to e-cigarettes.Methods:Using 19 684 residents data from the Beijing Non-communication Chronic Disease and Risk Factors Surveillance in 2022, complex sampling weighted methods were used to estimate proportions, and complex sampling logistic regression analysis was applied to explore the relationship between e-cigarette use, cigarette smoking, and smoking cessation.Results:Among all study participants, the proportion of those who had ever used e-cigarettes was 3.36%, with the current e-cigarette use at 1.26%. The proportion of current e-cigarette users (1.87%) and the former e-cigarette users (3.47%) were higher ( χ2=64.70, P<0.001) among males compared to females (0.60% and 0.64% respectively). The top three reasons for using e-cigarettes were wanting to quit smoking, perceiving e-cigarettes as less harmful, and enjoying the flavors of e-cigarettes. 83.54% of e-cigarette users started with cigarettes. The results of the complex sampling multivariable logistic regression analysis showed that current smoking ( OR=61.35, 95% CI: 36.98-101.76) and former smoking ( OR=31.20, 95% CI: 15.52-62.71) were positively associated with e-cigarette, while current e-cigarette use ( OR=0.13, 95% CI: 0.04-0.39) was negatively associated with quitting cigarette smoking. Conclusions:The proportion of e-cigarette use in Beijing was relatively low. E-cigarette use was associated with cigarette use and was not conducive to smoking cessation. Therefore, stronger regulatory measures and health education campaigns regarding the risks of e-cigarettes should be implemented.

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.