ObjectiveThe exacerbating trend of global population aging poses profound socioeconomic and public health challenges, making the comprehensive elucidation of biological aging mechanisms and the discovery of effective anti-aging interventions an urgent priority in the life sciences. Based on our previous serum metabolomics findings that dimethylglycine, an intermediate metabolite of amino acid metabolism naturally present in the human body, was significantly enriched in the serum of longevity families, this study aimed to systematically investigate the anti-aging effects of dimethylglycine both in living organisms and in controlled laboratory environments, and to preliminarily elucidate its underlying molecular mechanisms. While existing literature indicates that dimethylglycine possesses antioxidant and immunomodulatory properties, its direct anti-aging efficacy and the specific molecular pathways through which it operates remain largely unexplored. MethodsTo comprehensively evaluate the anti-aging properties of dimethylglycine, we utilized replicative senescent human embryonic lung fibroblasts, specifically the WI-38 cell line, as an experimental model in a controlled laboratory environment. Cell viability and safety were thoroughly assessed using Cell Counting Kit-8 and lactate dehydrogenase release assays across various concentrations of dimethylglycine. The impact of dimethylglycine on cellular senescence phenotypes, oxidative stress, and proliferative capacity was evaluated via senescence-associated beta-galactosidase staining, reactive oxygen species fluorescence detection, and 5-ethynyl-2'-deoxyuridine incorporation assays. Furthermore, the molecular alterations of senescence-associated secretory phenotype factors and core senescence signaling pathways were quantified using quantitative reverse transcription polymerase chain reaction for the messenger RNA levels of interleukin-6, interleukin-8, p21, and matrix metalloproteinase-1, and enzyme-linked immunosorbent assay for the measurement of p16 and p21 protein expression levels. For the living organism model, the wild-type nematode Caenorhabditis elegans was used to evaluate systemic physiological effects. We conducted a comprehensive lifespan analysis at 20°C, heat stress resistance survival assays at 35℃, senescence-associated beta-galactosidase staining, lipofuscin accumulation tracking, intracellular reactive oxygen species measurement, and Oil Red O staining to ascertain systemic lipid accumulation. Additionally, network pharmacology bioinformatics tools, including PharmMapper and STRING databases, and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were utilized to predict target pathways, alongside highly detailed molecular docking simulations utilizing SwissDock and Protein-Ligand Interaction Profiler to examine interactions with the cytochrome P450 family 2 subfamily C member 9 protein. ResultsThe experimental outcomes robustly demonstrate the potent anti-aging capabilities of dimethylglycine. At the cellular level, toxicity analyses firmly confirmed that dimethylglycine is highly safe; continuous treatment with 50 mol/L and 70 mol/L of dimethylglycine for 5 d did not induce any cellular membrane damage or cytotoxicity, but rather actively promoted cellular proliferation. Utilizing the optimal standardized concentration of 50 mol/L, dimethylglycine treatment significantly ameliorated senescent phenotypic markers in human embryonic lung fibroblasts, which was evidenced by a drastic and highly significant reduction in the senescence-associated beta-galactosidase positive cell percentage (P<0.000 1) and intracellular reactive oxygen species levels (P<0.000 1), alongside a marked increase in the 5-ethynyl-2'-deoxyuridine-positive proliferation rate (P=0.003 5). On a molecular expression scale, dimethylglycine significantly downregulated the messenger RNA expression of multiple core senescence-associated secretory phenotype inflammatory factors, including interleukin-6, interleukin-8, p21, and matrix metalloproteinase-1. Concurrently, it effectively suppressed the protein expression of critical cell cycle arrest markers, diminishing p16 protein levels by 57.3% (P=0.000 4) and p21 protein levels by 27.2% (P=0.000 7). In the nematode Caenorhabditis elegans animal model, dimethylglycine significantly extended the mean lifespan from 20.402 d to an impressive 23.066 d (P<0.000 1) and notably enhanced overall survival rates under severe heat stress environmental conditions (P=0.017). Furthermore, systemic dimethylglycine intervention significantly mitigated age-related physiological decline by decreasing bodily lipofuscin accumulation (P<0.000 1), significantly reducing senescence-associated beta-galactosidase activity, lowering systemic reactive oxygen species fluorescence (P=0.008), and effectively alleviating overall fat accumulation (P<0.000 1). Mechanistically, extensive network pharmacology and Kyoto Encyclopedia of Genes and Genomes analyses strongly revealed that the potential targets of dimethylglycine are significantly enriched in fundamental drug metabolism and oxidative stress response pathways. Precision molecular docking simulations conclusively demonstrated that dimethylglycine forms highly stable structural interactions with the cytochrome P450 family 2 subfamily C member 9 protein, specifically highlighting the definitive formation of 5 stable hydrogen bonds involving serine 365, leucine 366, and serine 429 residues, as well as two critical salt bridge formations with arginine 97 and histidine 368 residues. It is additionally predicted to interact favorably with glutathione S-transferase family proteins. ConclusionDimethylglycine exhibits a profoundly significant and multifaceted anti-aging activity at both the cellular and entire living animal levels. By powerfully alleviating oxidative stress, heavily suppressing the core p16 and p21-dependent cellular senescence signaling pathways, and substantially mitigating the detrimental senescence-associated secretory phenotype, dimethylglycine effectively delays fundamental cellular senescence processes and drastically extends whole-organism lifespan. The biological mechanisms driving these robust protective effects are highly likely closely associated with its direct stable interactions with crucial metabolic and detoxifying enzyme systems, such as cytochrome P450 family 2 subfamily C member 9 and glutathione S-transferase family proteins, thereby systemically improving metabolic dysregulation and restoring critical redox homeostasis. This comprehensive study provides highly solid experimental evidence supporting dimethylglycine as a highly potent and safe potential anti-aging intervention agent, while simultaneously offering a clear molecular mechanistic explanation for the previously documented high abundance of dimethylglycine observed within exceptionally long-lived human populations.

Background: Maturity-onset diabetes of the young (MODY) due to variants of hepatocyte nuclear factor 1-beta (HNF1β) (MODY5) has not been well studied in the Chinese population. This study aimed to estimate its prevalence and evaluate the application of a clinical screening method (Faguer score) in Chinese early-onset diabetes (EOD) patients. Methods: Among 679 EOD patients clinically diagnosed with type 2 diabetes mellitus (age at diagnosis ≤40 years), the exons of HNF1β were sequenced. Functional impact of rare variants was evaluated using a dual-luciferase reporter system. Faguer scores ≥8 prompted multiplex ligation-dependent probe amplification (MLPA) for large deletions. Pathogenicity of HNF1β variants was assessed following the American College of Medical Genetics and Genomics (ACMG) guidelines. Results: Two rare HNF1β missense mutations (E105K and G454R) were identified by sequencing in five patients, showing functional impact in vitro. Another patient was found to have a whole-gene deletion by MLPA in 22 patients with the Faguer score above 8. Following ACMG guidelines, six patients carrying pathogenic or likely pathogenic variant were diagnosed with MODY5. The estimated prevalence of MODY5 in Chinese EOD patients was approximately 0.9% or higher. Conclusion MODY5 is not uncommon in China. The Faguer score is helpful in deciding whether to perform MLPA analysis on patients with negative sequencing results.

Objective To investigate the mechanism of Kuijie Ankang Decoction in regulating immune,autophagy and intestinal flora in the treatment of ulcerative colitis(UC).Methods UC mouse model was established by free drinking with sodium dextran sulfate.The mice were randomly divided into blank control group,model group,Kuijie Ankang Decoction group,salazine sulfopyridine(SASP)group and 3-methyladenine(3-MA)group,with 12 mice in each group.Each drug group was given corresponding drugs for gavage,the blank control group and model group were given the same volume of distilled water for gavage for 7 days.The general condition of mice was observed and the disease activity index(DAI)was scored,the morphology of colon tissue was observed by HE staining,the contents of TNF-α,IL-1β,IL-6,IL-8 and IL-10 in colon tissue were detected by ELISA,the mRNA and protein expressions of LC3,Beclin-1 and p62 in colon tissue were detected by RT-qPCR and Western blot,respectively.16S rDNA sequencing was used to analyze the structure of intestinal flora.Results Compared with the blank control group,the mice in the model group showed a decrease in body mass,an increase in DAI score,a decrease in colon length,serious mucosal injury and inflammatory cell infiltration,the contents of TNF-α,IL-1β,IL-6 and IL-8 in colon tissue significantly increased(P<0.05,P<0.01),the content of IL-10 decreased(P<0.01),the mRNA expressions of LC3 and Beclin-1 in colon tissue decreased(P<0.05,P<0.01),the mRNA and protein expression of p62 increased(P<0.01),while the expressions of LC3Ⅱ/LC3Ⅰ and Beclin-1 proteins decreased(P<0.05,P<0.01).Compared with the model group,the body mass of mice in Kuijie Ankang Decoction group and SASP group increased(P<0.05),DAI score decreased(P<0.05),the colon length increased(P<0.05),the pathological damage of colon mucosa was alleviated,the contents of TNF-α,IL-1β,IL-6 and IL-8 in colon tissue decreased(P<0.05,P<0.01),the content of IL-10 increased(P<0.01),the expressions of LC3 and Beclin-1 mRNA in colon tissue increased(P<0.05,P<0.01),the expression of p62 mRNA and protein decreased(P<0.05,P<0.01),the expressions of LC3Ⅱ/LC3Ⅰand Beclin-1 protein increased(P<0.05,P<0.01).16S rDNA sequencing results showed that the diversity and evenness of the intestinal flora in the model group mice decreased,with a decrease in the relative abundance of Firmicutes,Actinobacteria and Patescibacteria(P<0.05),and an increase in the relative abundance of Bacteroidota,Verrucomicrobiota and Proteobacteria(P<0.05);the relative abundance of Bacilli and Coriobacteriia decreased(P<0.05),the relative abundance of Bacteroidia,Clostridia and Verrucomicrobiae increased(P<0.05);the relative abundance of Ligilactobacillus and Dubosiella decreased(P<0.05),the relative abundance of unclassified Muribaculaceae,Lachnospiraceae NK4A136_group,Akkermansia and unclassified Lachnospiraceae increased(P<0.05).Compared with the model group,the diversity and evenness of intestinal flora increased in Kuijie Ankang Decoction group and SASP group,with an increase in the relative abundance of Firmicutes(P<0.05),a decrease in the relative abundance of Bacteroidota and Verrucomicrobiota(P<0.05),the relative abundance of Bacteroidia and Bacilli increased(P<0.05),the relative abundance of Verrucomicrobiae decreased(P<0.05);the relative abundance of unclassified Muribaculaceae and Ligilactobacillus increased(P<0.05),while the relative abundance of Lachnospiraceae NK4A136_group and Akkermansia decreased(P<0.05).Conclusion Kuijie Ankang Decoction can significantly improve the intestinal mucosal injury of UC mice,and the mechanism may be related to the regulation of colon autophagy level and intestinal flora disorder.

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 analyze the clinicopathological data of invasive stratified mucinous carcinoma(ISMC)of the cervix,thereby providing comprehensive insights for the diagnosis,treatment,and prognosis of this disease.Methods:A retrospective analysis was conducted on 23 cases of ISMC admitted to the Department of Gynecolo-gy at Wuhan University People's Hospital and the Department of Obstetrics and Gynecology at the Second Affilia-ted Hospital of Fujian Medical University between January 2020 and December 2023.The study examined clinical characteristics,pathological features,immunohistochemical results,and prognostic outcomes.Additionally,we compared the prognostic data of 14 cases of cervical gastric adenocarcinoma and 19 cases of cervical neuroendo-crine carcinoma.Results:A total of 23 patients diagnosed with ISMC ranged in age from 27 to 61 years,with 11(47.83％)being postmenopausal.Only one patient exhibited lesions upon physical examination,while the remai-ning patients presented with varying degrees of vaginal bleeding,sometimes accompanied by abnormal vaginal discharge and other symptoms.Among these patients,three were HPV-negative,while the remainder tested posi-tive for HPV,with types 16 and 18 being the most prevalent.Of the 23 patients,15 had isolated ISMC,five had in-vasive cervical adenocarcinoma with partial ISMC involvement,and three had cervical adenosquamous carcinoma with partial ISMC involvement.ISMC patients tested positive(100.00％)for p16 and CK7,with positivity rates of 26.09％for p16 and 9.52％for CK7.Immunohistochemical analysis of p53 was conducted in 15 ISMC patients,re-vealing that 80.00％(12/15)had wild-type p53,while 20.00％had mutant p53.The proportion of patients with a Ki-67 proliferation index above 60％was 77.27％(17/22).The mean follow-up period for the 15 patients with isola-ted ISMC was 10.0 months(1.0-36.0 months),with a recurrence rate of 20.00％and a mortality rate of 6.67％.For the 14 patients with combined diagnoses,the mean follow-up period was 9.5 months(1.0-35.0 months),with a recurrence rate of 50.00％and a mortality rate of 7.14％.In the case of 19 patients with cervical neuroen-docrine carcinoma,the mean follow-up period was 15.0 months(1.0-33.0 months),with a recurrence rate of 31.58％and a mortality rate of 10.52％.However,no statistically significant differences were observed in the recur-rence or mortality rates between cervical neuroendocrine carcinoma and isolated ISMC(P＞0.05).Conclusions:The primary clinical manifestation of ISMC is characterized by vaginal bleeding or abnormal fluid discharge,which demonstrates a strong association with HPV infection.Notably,ISMC lacks specific tumor markers for diagnosis.However,immunohistochemical analysis reveals distinctive molecular expression patterns that may serve as effec-tive diagnostic indicators.It is important to emphasize that ISMC exhibits comparable recurrence and mortality rates to those observed in cervical gastric adenocarcinoma and cervical neuroendocrine carcinoma,underscoring its aggressive clinical behavior.

Objective:To establish an inductively coupled plasma mass spectrometry (ICP-MS) method for the rapid determination of total bromine in whole blood, and to provide technical support for the monitoring of bromine exposure in occupational populations.Methods:In September 2023, 0.25 ml of whole blood sample was added with 0.25% tetramethylammonium hydroxide solution to a volume of 5.0 ml, ultrasonicated and homogenized, and then quantified by ICP-MS with rhodium solution as the online internal standard solution.Results:The linear relationship of bromine in blood was good within the range of 0~10.00 mg/L, with a correlation coefficient ( r) >0.999. The limit of detection of the method was 0.07 mg/L, and the quantification limit was 0.22 mg/L. The recoveries of the total bromine in whole blood were in the range of 95.5%-102.9%, and the relative standard deviations (RSDs) were in the range of 3.1%-4.7% ( n=7) . Conclusion:An ICP-MS method was established for the rapid determination of total bromine in whole blood, which is accurate, simple, rapid, highly automated, and can be used for the determination of total bromine in whole blood of occupationally exposed people.

Objective:To explore impacts of nuciferine(Nuci)on liver fibrosis and inflammatory reaction in cirrhotic rats through p38MAPK-PPARγ/NF-κB signal pathway.Methods:Six SD rats were randomly selected as control(NC)group,other rats were injected with thioacetamide(TAA)into peritoneum at a dose of 200 mg/kg to induce cirrhosis.Rats successfully modeled were randomly grouped into Model group,Nuci group(20 mg/kg Nuci),anisomycin group(5 mg/kg Nuci p38MAPK-PPARγ/NF-κB signal pathway activator anisomycin),and Nuci+anisomycin group(20 mg/kg Nuci+5 mg/kg anisomycin),with 6 rats in each group.The NC group and the Model group were given the same amount of normal saline once a day for 8 weeks.Serum inflammatory index and liver function index were detected by ELISA kits;HE staining was applied to detect pathological changes of liver;Masson staining was applied to detect liver fibrosis;Western blot was applied to detect pathway related proteins levels.Results:In NC group,cell structure was normal,only a small amount of collagen was deposited,no collagen fiber proliferation was observed,and liver lobule was clearly stained.Compared with NC group,hepatocytes in Model group were enlarged,accompanied by inflammatory cell infiltration,and in-creased collagen fiber proliferation,IL-1β,TNF-α,alanine aminotransferase(ALT),IL-6,hyaluronic acid(HA),aspartate amino-transferase(AST),type Ⅲ procollagen(PCⅢ),total bilirubin(TBIL)content,laminin(LN),collagen volume fraction,p-p38MAPK/p38MAPK,p-NF-κB p65/NF-κB p65 proteins levels were significantly increased(P<0.05),PPARγ protein level was significantly decreased(P<0.05).Nuci treatment improved inflammatory cell infiltration and necrosis in liver tissue,levels of IL-1β,IL-6,TNF-α,ALT,AST,TBIL,HA,LN,PCⅢ,collagen volume fraction,p-p38MAPK/p38MAPK,p-NF-κB p65/NF-κB p65 pro-teins were significantly decreased(P<0.05),PPARγ protein level was significantly increased(P<0.05),trend of anisomycin group was opposite to that of Nuci group;anisomycin eliminated therapeutic effect of Nuci on cirrhotic rats.Conclusion:Nuci may reduce liver fibrosis and inflammation in cirrhotic rats by down-regulating p38MAPK-PPARγ/NF-κB signal pathway.

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.