Objective To investigate the impact of high mobility group box 1(HMGB1)on hydrogen peroxide(H2O2)-induced DNA damage and senescence in lens epithelial cells(LECs)under oxidative stress conditions.Methods Fluorescent quantitative real-time polymerase chain reaction(RT-PCR)technology was used to detect the mRNA expres-sion of HMGB1 in the anterior capsule tissue of patients with age-related cataract(ARC group)and epiretinal membrane(control group).Western blot analysis was employed to examine the changes in the protein expression of HMGB1 in the LEC line SRA01/04 after treatment with varying concentrations of H2O2(0,100,200,and 400 μmol·L-1).The optimal concentration was selected for subsequent establishment of a cellular oxidative damage model.The cultured SRA01/04 cells were divided into three groups:Control(untreated),HA(transfected with the control plasmid HA),and OE-HMGB1 groups(transfected with the HMGB1 plasmid).The mRNA and protein expression levels of HMGB1 were detected by RT-PCR and Western blot.The cultured SRA01/04 cells were divided into three groups:H2O2(treated with 400 μmol·L-1 H2O2),H2O2+HA(transfected with the control plasmid HA and simultaneously treated with 400 μmol·L-1 H2O2),and H2O2+OE-HMGB1 groups(transfected with the HMGB1 plasmid and simultaneously treated with 400 μmol·L-1 H2O2).Immunofluorescence was used to detect DNA oxidative damage in cells from each group.Western blot analysis was per-formed to assess the protein expression levels of phosphorylated histone H2A(γH2A),tumor protein p53(P53),cyclin-dependent kinase inhibitor 1A(P21),and cyclin-dependent kinase inhibitor 2A(P16)in cells from each group.Additional-ly,senescence-associated-β-galactosidase(SA-β-gal)staining was conducted to detect senescent changes in cells from each group.Results RT-PCR results indicated that the relative mRNA expression level of HMGB1 in the anterior capsule tissue of the ARC group was significantly decreased,compared with that in the control group(P＜0.001).Furthermore,in the H2O2-induced oxidative damage model,the relative protein expression level of HMGB1 decreased with the increase of the concentration of H2O2.Both RT-PCR and Western blot analyses revealed that the mRNA and protein expression levels of HMGB1 were both significantly elevated in the OE-HMGB1 group,compared with those in the HA group(both P＜0.001).The immunofluorescence staining results demonstrated that the protein expression of γH2A and the fluorescence intensity in the H2O2+OE-HMGB1 group were significantly decreases,compared with those in H2O2 and H2O2+HA groups(all P＜0.001).SA-β-gal staining results showed that the H2O2+OE-HMGB1 group had significantly less cells stained by SA-β-gal than H2O2 and H2O2+HA(both P＜0.001).Additionally,Western blot analysis revealed that,compared with those in H2O2 and H2O2+HA groups,the relative expression levels of senescence-associated proteins P53,P21,and P16 were significantly decreased in the H2O2+OE-HMGB1 group(all P＜0.01).Conclusion HMGB1 inhibits the accumula-tion of damaging DNA and senescence in LECs by enhancing DNA damage repair capabilities.

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 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 influence of body mass index(BMI)on individualized analgesic effect,inflammatory factors and safety of sufentanil in elderly patients after proximal femoral nail anti-rotation(PFNA)surgery.Methods A total of 161 elderly patients who received PFNA surgery in Nanjing Drum Tower Hospital Group Suqian Hospital from January 2022 to December 2023 were selected as study subjects.Patients with BMI<18.5 kg/m2 were set as Group A,patients with BMI ranging from 18.5 kg/m2 to 23.9 kg/m2 were set as Group B,patients with BMI ranging from 24.0 kg/m2 to 35.0 kg/m2 were set as Group C.After operation,individualized analgesia was performed with an intravenous patient-controlled analgesia pump of 2 μg/kg sufentanil based on body weight,and the postoperative pain degree,inflammatory factors,analgesia condition and adverse reactions of patients in the three groups were compared.Results At 8 hours,12 hours,24 hours and 48 hours after surgery,the pain visual analogue scale(VAS)scores of patietns in group B and group C were significantly lower than those in group A(P<0.05).At 12 hours,24 hours and 48 hours after surgery,the pain VAS scores of patients in group C were significantly lower than those in group B(P<0.05).The levels of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β),and interleukin-6(IL-6)1 day after surgery of patients in group B and group C were significantly lower than those in group A(P<0.05).The pressing times of analgesia pump and the duration of obvious pain within 48 hours after surgery of patients in group A were significantly more/longer than those in group B and group C(P<0.05),and the analgesic satisfaction score was significantly lower than those in group B and group C(P<0.05).The total incidence of analgesic adverse reactions in group C was significantly higher than those in group A and group B(P<0.05).Conclusion BMI may affect the individualized analgesic effect,inflammatory factors and safety of sufentanil in elderly patients undergoing PFNA surgery.Underweight patients may have insufficient analgesia,while overweight or obese patients may have excessive analgesia,which may affect the analgesic safety.

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 impact of high mobility group box 1(HMGB1)on hydrogen peroxide(H2O2)-induced DNA damage and senescence in lens epithelial cells(LECs)under oxidative stress conditions.Methods Fluorescent quantitative real-time polymerase chain reaction(RT-PCR)technology was used to detect the mRNA expres-sion of HMGB1 in the anterior capsule tissue of patients with age-related cataract(ARC group)and epiretinal membrane(control group).Western blot analysis was employed to examine the changes in the protein expression of HMGB1 in the LEC line SRA01/04 after treatment with varying concentrations of H2O2(0,100,200,and 400 μmol·L-1).The optimal concentration was selected for subsequent establishment of a cellular oxidative damage model.The cultured SRA01/04 cells were divided into three groups:Control(untreated),HA(transfected with the control plasmid HA),and OE-HMGB1 groups(transfected with the HMGB1 plasmid).The mRNA and protein expression levels of HMGB1 were detected by RT-PCR and Western blot.The cultured SRA01/04 cells were divided into three groups:H2O2(treated with 400 μmol·L-1 H2O2),H2O2+HA(transfected with the control plasmid HA and simultaneously treated with 400 μmol·L-1 H2O2),and H2O2+OE-HMGB1 groups(transfected with the HMGB1 plasmid and simultaneously treated with 400 μmol·L-1 H2O2).Immunofluorescence was used to detect DNA oxidative damage in cells from each group.Western blot analysis was per-formed to assess the protein expression levels of phosphorylated histone H2A(γH2A),tumor protein p53(P53),cyclin-dependent kinase inhibitor 1A(P21),and cyclin-dependent kinase inhibitor 2A(P16)in cells from each group.Additional-ly,senescence-associated-β-galactosidase(SA-β-gal)staining was conducted to detect senescent changes in cells from each group.Results RT-PCR results indicated that the relative mRNA expression level of HMGB1 in the anterior capsule tissue of the ARC group was significantly decreased,compared with that in the control group(P＜0.001).Furthermore,in the H2O2-induced oxidative damage model,the relative protein expression level of HMGB1 decreased with the increase of the concentration of H2O2.Both RT-PCR and Western blot analyses revealed that the mRNA and protein expression levels of HMGB1 were both significantly elevated in the OE-HMGB1 group,compared with those in the HA group(both P＜0.001).The immunofluorescence staining results demonstrated that the protein expression of γH2A and the fluorescence intensity in the H2O2+OE-HMGB1 group were significantly decreases,compared with those in H2O2 and H2O2+HA groups(all P＜0.001).SA-β-gal staining results showed that the H2O2+OE-HMGB1 group had significantly less cells stained by SA-β-gal than H2O2 and H2O2+HA(both P＜0.001).Additionally,Western blot analysis revealed that,compared with those in H2O2 and H2O2+HA groups,the relative expression levels of senescence-associated proteins P53,P21,and P16 were significantly decreased in the H2O2+OE-HMGB1 group(all P＜0.01).Conclusion HMGB1 inhibits the accumula-tion of damaging DNA and senescence in LECs by enhancing DNA damage repair capabilities.

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.