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 summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.

Objective: To investigate the association between childhood obesity and type 2 diabetes mellitus (T2DM) as well as coronary artery heart disease (CHD). Methods: Genome-wide association study (GWAS) data for childhood obesity were collected from the ECG consortium, encompassing information on children aged 2 to 18 years, including 18 613 cases and 12 696 controls. GWAS data for T2DM were collected from the DIAGRAM consortium, including 242 283 cases and 1 569 734 controls. GWAS data for CHD were collected from the CARDIoGRAMplusC4D consortium, including 10 801 cases and 137 371 controls. Pleiotropic genes associated with both T2DM and CHD were analyzed using the MAGMA, PLACO and conditional false discovery rate (cFDR) methods. Mendelian randomization (MR) analysis was performed using inverse variance weighted (IVW) method, exploring the causal relationships among childhood obesity, T2DM and CHD. Heterogeneity was evaluated using Cochran's Q test, horizontal pleiotropy and exclude outliers were tested using MR-Egger regression and MR-PRESSO test. The mediating variables among the three diseases were investigated by using a mediation analysis. Results: The results of MAGMA, PLACO and cFDR analyses identified 80 pleiotropic genes associated with both T2DM and CHD, primarily distributed on chromosomes 3, 17 and 19. The MR analysis revealed that childhood obesity increased the risk of T2DM (OR=1.151, 95%CI: 1.033-1.283) and CHD (OR=1.158, 95%CI: 1.068-1.255), T2DM increased the risk of CHD (OR=1.182, 95%CI: 1.139-1.227), and CHD increased the risk of T2DM (OR=1.124, 95%CI: 1.055-1.198). The MR-Egger regression analysis showed no horizontal pleiotropy, and the MR-PRESSO test did not identify any outliers (all P>0.05). Mediation analysis indicated that childhood obesity directly increased the risk of CHD (effect value=0.096, 95%CI: 0.012-0.180) and indirectly increased the risk of CHD through T2DM (effect value=0.023, 95%CI: 0.005-0.041), with the mediation effect accounting for 15.65% of the total effect. Conclusions There are potential causal associations between childhood obesity and T2DM as well as CHD, with a bidirectional causal relationship between T2DM and CHD. T2DM also plays a mediating role in the association between childhood obesity and CHD.

Objective: To investigate the spatio-temporal clustering characteristics of influenza in Shaoxing City, Zhejiang Province from 2015 to 2024, so as to provide the basis for formulating influenza prevention and control strategies. Methods: Influenza case data in Shaoxing City from 2015 to 2024 were collected through the Infectious Disease Surveillance Reporting System of the Chinese Disease Prevention and Control Information System. Descriptive epidemiological methods analyses were used to analyze the epidemiological characteristics of influenza. Spatial autocorrelation and spatio-temporal scanning were used to analyze the spatio-temporal clustering characteristics of influenza. Results: A total of 328 759 influenza cases were reported in Shaoxing City from 2015 to 2024, with an average annual reported incidence of 639.90/100 000, which showed an upward trend (AAPC=68.95%, P<0.05). The peak incidence period was from December to February of the following year, with 193 051 cases reported, accounting for 58.72%. There were 165 408 male cases and 163 351 female cases, with a male-to-female ratio of 1.01∶1. Children and adolescents aged 0-<15 years constituted the high-incidence population, while students represented the predominant occupational category, comprising 113 589 cases (34.55%). Keqiao District, Shengzhou City, and Yuecheng District had the top three average annual reported incidence of influenza, at 995.64/100 000, 734.66/100 000, and 687.44/100 000, respectively. Spatial autocorrelation analysis showed that, there were 155 high-high aggregation areas in Shaoxing City from 2015 to 2024, which gradually expanded from the local aggregation in the central part of Shengzhou City to Keqiao District and then spread to Yuecheng District. Spatio-temporal scanning analysis showed that, from November 2023 to February 2024, the strongest spatio-temporal clustering of influenza centered on Keqiao Street in Keqiao District, covering 11 towns (streets) in Yuecheng District and Keqiao District. From 2015 to 2018, the primary-type clustering of influenza was mainly concentrated in Xinchang County and Shengzhou City. After 2019, they gradually shifted to Yuecheng District and Keqiao District, with the main clustering period being from November to February of the following year. Conclusions The incidence of influenza in Shaoxing City from 2015 to 2024 showed an upward trend, with obvious spatio-temporal clustering. The clustering area expanded from Shengzhou City in the central region to Keqiao District and Yuecheng District in the northern region, mainly clustering from November to February of the following year.

Objective: To investigate the epidemiological characteristics of hepatitis E in Shaoxing City, Zhejiang Province from 2006 to 2024, so as to provide the evidence for the prevention and control of hepatitis E. Methods: Data on hepatitis E incidence in Shaoxing City from 2006 to 2024 were collected through the Surveillance System of China Information System for Disease Control and Prevention. The epidemiological characteristics were analyzed using descriptive epidemiological methods. The trend in hepatitis E incidence was analyzed using the average annual percent change (AAPC) and annual percent change (APC). The spatial-temporal clustering characteristics of hepatitis E incidence were identified using spatial-temporal scanning analysis. Results: A total of 2 408 hepatitis E cases were reported in Shaoxing City from 2006 to 2024, with an average annual reported incidence of 2.55/100 000. The overall trend was not statistically significant (AAPC=3.181%, P>0.05). Specifically, it showed an upward trend from 2006 to 2011 (APC=17.371%, P<0.05), a downward trend from 2011 to 2019 (APC=-12.497%, P<0.05), and an upward trend from 2019 to 2024 (APC=18.076%, P<0.05). The epidemic season of hepatitis E was from January to May, with seasonal indices of 122.09%, 118.60%, 145.02%, 129.57%, and 106.15%, respectively. The top three average annual reported incidences were identified in Zhuji City, Xinchang County, and Shengzhou City, with rates of 4.18/100 000, 2.85/100 000, and 2.74/100 000, respectively. The average annual reported incidence of hepatitis E was higher in males than in females (3.52/100 000 vs. 1.56/100 000, P<0.05). A relatively large number of hepatitis E cases were reported among individuals aged 40-<70 years, with 1 639 cases (68.06%). Among them, the group aged 60-<70 years had the highest average annual reported incidence of hepatitis E, at 4.92/100 000. Farmers constituted the predominant occupational group, accounting for 1 515 cases (62.92%). Spatial-temporal scanning analysis identified two clusters in Shaoxing City from 2006 to 2024. The class Ⅰ cluster was located in Shengzhou City, with aggregation time from January 1, 2011 to May 1, 2014. The class Ⅱ cluster was located in Xinchang County, with aggregation time from December 1, 2012 to March 31, 2013. Conclusions The reported incidence of hepatitis E in Shaoxing City from 2006 to 2024 exhibited a pattern of an initial increase, followed by a decrease, and then a subsequent rise. The disease demonstrated higher prevalence during the winter and spring seasons. Key populations for targeted control and prevention include males, individuals aged 40-<70 years, and farmers. Shengzhou City and Xinchang County were identified as high-risk areas.

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 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.