ObjectiveThe present study aimed to investigate alterations in white matter microstructure and spontaneous neural activity in male college smokers, and to further explore their associations with nicotine dependence. Given that adolescence and early adulthood represent critical periods for brain maturation, particularly for white matter development, understanding the neural correlates of smoking behavior during this stage is of substantial importance for both neuroscience and public health. MethodsA total of 115 male undergraduate students were initially recruited for this study. After quality control and exclusion procedures, 52 male college smokers and 42 demographically matched healthy non-smokers were included in the final analysis. All participants underwent multimodal magnetic resonance imaging (MRI), including diffusion tensor imaging (DTI) and resting-state functional MRI (rs-fMRI). White matter fiber tracts were reconstructed using the automated fiber quantification (AFQ) method, which enables precise identification and quantification of major fiber bundles. Eighteen major white matter tracts were segmented for each participant. Along the core trajectory of each tract, 100 equidistant nodes were sampled. Fractional anisotropy (FA) was calculated at each node to assess white matter microstructural integrity, while amplitude of low-frequency fluctuation (ALFF) was computed to evaluate spontaneous neural activity within white matter tracts. Between-group differences in FA and ALFF were assessed using two-sample t-tests, with appropriate corrections applied for multiple comparisons. Furthermore, Pearson correlation analyses were conducted to examine the relationships between imaging-derived metrics (FA and ALFF values in regions showing significant group differences) and nicotine dependence severity, as measured by the Fagerström test for nicotine dependence (FTND). ResultsCompared with healthy non-smokers, male college smokers exhibited significantly increased FA values in several white matter tracts, including the left thalamic radiation, right corticospinal tract, forceps major of the corpus callosum, left uncinate fasciculus, and right arcuate fasciculus. These findings suggest altered microstructural organization or increased directional coherence within these pathways. In addition, smokers demonstrated significantly elevated ALFF values in the forceps major, right uncinate fasciculus, and left arcuate fasciculus, indicating enhanced spontaneous neural activity in these white matter regions. Correlation analyses revealed that FA values in the left thalamic radiation and right corticospinal tract were negatively correlated with FTND scores, suggesting that higher levels of nicotine dependence were associated with reduced microstructural integrity or altered fiber organization in these regions. In contrast, ALFF values in the forceps major and right uncinate fasciculus were positively correlated with FTND scores, indicating that greater nicotine dependence was associated with increased spontaneous neural activity in specific white matter pathways. ConclusionThe present study provides evidence that male college smokers exhibit distinct alterations in both white matter microstructure and functional activity. These abnormalities are not uniformly distributed but rather localized to specific fiber tracts implicated in sensorimotor processing, interhemispheric communication, and higher-order cognitive and emotional regulation. Importantly, the observed associations between imaging metrics and nicotine dependence severity suggest that these structural and functional alterations may reflect neurobiological mechanisms underlying addiction. The combination of AFQ-based tract profiling and multimodal MRI offers a sensitive approach for detecting subtle changes along white matter pathways, highlighting its potential utility in identifying neuroimaging biomarkers of nicotine dependence. Overall, these findings indicate that smoking during early adulthood may disrupt ongoing white matter maturation, potentially leading to long-term consequences for brain function. This study provides novel insights into the neural basis of nicotine dependence and underscores the importance of early intervention and prevention strategies targeting young smokers.

Objective To gain insights into the biological characteristics of different populations of Culex tritaeniorhynchus within and around the Yellow Sea wetland from the perspective of the occurrence of resistance, we investigated the levels of resistance to deltamethrin and kdr gene mutation in the wetland and its peripheral areas. Methods Specimens were collected from Cx. tritaeniorhynchus populations at two monitoring sites in the Rare Bird National Nature Reserve and Tiaozi Ni Wetland Scenic Area, and also from two populations in Yancheng City and the Liuhe District of Nanjing, and the resistance of these mosquitoes to deltamethrin was determined using the CDC biotest bottle method. For each concentration of deltamethrin assessed, a random subset of exposed specimens was selected for amplification of the kdr gene fragment, followed by Sanger sequencing to identify and analyze resistance-associated mutations. Results The LC50 levels of deltamethrin among mosquitoes from the four populations in Luhe, Yancheng, the Rare Bird National Nature Reserve and the Tiaozi Ni Wetland Scenic Area were 2.048 5, 7.798 2, 3.473 3, and 17.695 5 mg/mL, respectively, with corresponding concentrations of deltamethrin ranging from 0.005 to 5.000,0.050 to 50.000,0.050 to 25.000 and 0.050 to 50.000 mg/mL, respectively. Furthermore, the ranges of the KT50 values were 11.76-107.43, 67.05-216.30,29.77-107.43 and 28.40-329.51 min; the 1-h knockdown rates were 34.58%-99.15%, 9.52%-43.80%, 55.09%-73.01%, and 10.09%-68.07%; and the 24-h mortality rates were 12.15%-67.52%,9.52%-79.56%,13.17%-82.21%, and 11.01%-78.99%, respectively. With respect to kdr gene mutation, we assayed a total of 63,70,59, and 57 mosquitoes for the four populations, for which we detected L1014F mutation frequencies of 14.29%, 35.00%, 20.34%, and 31.58%, respectively, with a majority of these mutations being heterozygous for resistance. In addition, five adult mosquitoes were identified has having synonymous mutations at site 1011[i. e. , AAT(asparagine)mutation to AAC(asparagine)]. Conclusions Our findings revealed the clear resistance of Cx. tritaeniorhynchus to deltamethrin in the Yancheng region of the Yellow Sea wetland, and the resistance phenotype and kdr frequency of Cx. tritaeniorhynchus in the wetland environment were comparable to those of Cx. tritaeniorhynchus in the wetland environment, thereby indicating that the resistance of different populations of Cx. tritaeniorhynchus was homogeneous under the pressure of different insecticide selection within and around the wetland. However, the underlying mechanisms need to be further studied.

OBJECTIVE To explore the clinical characteristics of the nontuberculous Mycobacteria pulmonary dis-ease(NTMPD)patients with previous pulmonary tuberculosis(PPTB)and analyze the clinical difference from the recurrence of pulmonary tuberculosis.METHODS By means of retrospective survey,the patients who were diag-nosed with NTMPD and recurrent pulmonary tuberculosis in Wuhan Pulmonary Hospital from Mar.2021 to Oct.2023 were recruited as the research subjects,a total of 395 patients with NTMPD were enrolled in the study and were divided into the PPTB-NTMPD group with 92 cases and the NPPTB-NTMPD group with 303 cases according to the history of PPTB.The baseline data,clinical symptoms,imaging findings,underlying diseases,pulmonary diseases,and species of nontuberculous Mycobacteria(NTM)were observed and compared.Totally 92 patients with recurrent pulmonary tuberculosis were randomly screened and assigned as the recurrent pulmonary tuberculo-sis group in a 1:1 ratio by matching the PPTB-NTMPD group with the gender and age.The major clinical charac-teristics were compared between the two groups.The 92 patients with PPTB-NTMPD were divided into the 1-10 years group with 40 cases,the 10-30 years group with 37 cases,and the more than 30 years group with 15 cases according to the interval between the initial diagnosis of pulmonary tuberculosis and the diagnosis of NTMPD.The major clinical characteristics were compared among the groups.RESULTS The age was(64.21±10.71)years old in the PPTB-NTMPD group,(60.26±11.83)years old in the NPPTB-NTMPD group(t=3.020,P=0.003).The proportion of patients with body mass index less than 18.5 kg/m2 was 59.78％in the PPTB-NTMPD group,41.25％in the NPPTB-NTMPD group(x2=6.155,P=0.013);the proportion of patients with cough was 77.17％in the PPTB-NTMPD group,65.68％in the NPPTB-NTMPD group(x2=4.313,P=0.038);the inci-dence of cavitary shadow was 50.00％in the PPTB-NTMPD group,35.31％in the NPPTB-NTMPD group(x2=6.414,P=0.011);the incidence of emphysema and pulmonary bullae was 29.35％in the PPTB-NTMPD group,12.87％in the NPPTB-NTMPD group(x2=13.766,P＜0.001);the incidence of chronic obstructive pulmonary disease(COPD)was 22.83％in the PPTB-NTMPD group,14.19％in the NPPTB-NTMPD group(x2=3.875,P=0.049);the incidence of damaged lung was 9.78％in the PPTB-NTMPD group,2.97％in the NPPTB-NT-MPD group(x2=7.530,P=0.014);there were significant differences.Mycobacterium intracellulare and Myco-bacterium abscessus were the predominant species of NTM in both the PPTB-NTMPD group and the NPPTB-NT-MPD group,there was no significant difference in the distribution of NTM species between the two groups of pa-tients.The incidence of patch shadow of the PPTB-NTMPD group was lower than that of the recurrent pulmonary tuberculosis group(P＜0.05),the incidence of bronchiectatic shadow of the PPTB-NTMPD group was higher than that of the recurrent pulmonary tuberculosis group(P＜0.05).There were significant differences in the age,incidence of pleural thickening and incidence of COPD among the patients with different time intervals between ini-tial diagnosis of pulmonary tuberculosis and the diagnosis of NTMPD in the PPTB-NTMPD group(P＜0.05).CONCLUSIONS The previous pulmonary tuberculosis mainly affect the body mass index less than 18.5 kg/m2 and the post-tuberculosis pulmonary diseases such as cough,pulmonary cavity,emphysema,pulmonary bullae,COPD and damaged lung of the NTMPD patients.The NTMPD patients with previous pulmonary tuberculosis are more likely to have bronchiectasia than the patients with recurrent tuberculosis.It is necessary for the clinicians to attach great importance.

Objective To assess coronary microvascular obstruction(MVO)after percutaneous coronary intervention in(PCI)patients with acute ST-segment elevation myocardial infarction(STEMI)and to investigate its value for patient prognosis.Methods We enrolled 97 patients who were hospitalized for acute STEMI at Wuhan Asia Heart Hospital from May 2021 to June 2024,underwent emergency PCI during hospitalization,and completed cardiac magnetic resonance(CMR)at a median of 7(5,8)days after the procedure.Patients were classified into MVO group(n=58)and non-MVO group(n=39)according to the results of CMR.Cox regression was used to analyse predictors of adverse events after PCI.Patients were followed for a median of 11.5(8.5,24.5)months for the occurrence of major adverse cardiovascular events(MACE,a composite outcome including readmission for heart failure,recurrent myocardial infarction,target vessel restenosis,target vessel revascularisation,and cardiac death)and secondary endpoint events(left ventricular remodelling,non-cardiac death).Results MVO was evidenced in 58 patients(59.79％).Multifactorial Cox regression analysis showed that MVO(HR 7.024,95％CI 1.408-35.027,P=0.017)and the proportion of inactive myocardium to the left ventricle(HR 1.066,95％CI 1.014-1.121,P=0.012)were the independent predictors factors for the incidence of adverse events in STEMI patients after PCI.The median follow-up time was 11.5(8.5,24.5)months.There was no statistically significant difference in the incidence of MACE between the MVO group and the non-MVO group(P=0.347).However,the MVO group had a higher incidence of secondary endpoints(32.76％ vs.2.56％,P＜0.001)and a higher incidence of left ventricular remodeling(29.31％ vs.2.56％,P＜0.001).Kaplan Meier survival analysis showed that the prognosis of the non-MVO group was significantly better than that of the MVO group(Log-rank P＜0.001).Conclusions MVO after PCI in patients with acute STEMI is a good predictor of clinical prognosis.

OBJECTIVE To explore the clinical characteristics of the nontuberculous Mycobacteria pulmonary dis-ease(NTMPD)patients with previous pulmonary tuberculosis(PPTB)and analyze the clinical difference from the recurrence of pulmonary tuberculosis.METHODS By means of retrospective survey,the patients who were diag-nosed with NTMPD and recurrent pulmonary tuberculosis in Wuhan Pulmonary Hospital from Mar.2021 to Oct.2023 were recruited as the research subjects,a total of 395 patients with NTMPD were enrolled in the study and were divided into the PPTB-NTMPD group with 92 cases and the NPPTB-NTMPD group with 303 cases according to the history of PPTB.The baseline data,clinical symptoms,imaging findings,underlying diseases,pulmonary diseases,and species of nontuberculous Mycobacteria(NTM)were observed and compared.Totally 92 patients with recurrent pulmonary tuberculosis were randomly screened and assigned as the recurrent pulmonary tuberculo-sis group in a 1:1 ratio by matching the PPTB-NTMPD group with the gender and age.The major clinical charac-teristics were compared between the two groups.The 92 patients with PPTB-NTMPD were divided into the 1-10 years group with 40 cases,the 10-30 years group with 37 cases,and the more than 30 years group with 15 cases according to the interval between the initial diagnosis of pulmonary tuberculosis and the diagnosis of NTMPD.The major clinical characteristics were compared among the groups.RESULTS The age was(64.21±10.71)years old in the PPTB-NTMPD group,(60.26±11.83)years old in the NPPTB-NTMPD group(t=3.020,P=0.003).The proportion of patients with body mass index less than 18.5 kg/m2 was 59.78％in the PPTB-NTMPD group,41.25％in the NPPTB-NTMPD group(x2=6.155,P=0.013);the proportion of patients with cough was 77.17％in the PPTB-NTMPD group,65.68％in the NPPTB-NTMPD group(x2=4.313,P=0.038);the inci-dence of cavitary shadow was 50.00％in the PPTB-NTMPD group,35.31％in the NPPTB-NTMPD group(x2=6.414,P=0.011);the incidence of emphysema and pulmonary bullae was 29.35％in the PPTB-NTMPD group,12.87％in the NPPTB-NTMPD group(x2=13.766,P＜0.001);the incidence of chronic obstructive pulmonary disease(COPD)was 22.83％in the PPTB-NTMPD group,14.19％in the NPPTB-NTMPD group(x2=3.875,P=0.049);the incidence of damaged lung was 9.78％in the PPTB-NTMPD group,2.97％in the NPPTB-NT-MPD group(x2=7.530,P=0.014);there were significant differences.Mycobacterium intracellulare and Myco-bacterium abscessus were the predominant species of NTM in both the PPTB-NTMPD group and the NPPTB-NT-MPD group,there was no significant difference in the distribution of NTM species between the two groups of pa-tients.The incidence of patch shadow of the PPTB-NTMPD group was lower than that of the recurrent pulmonary tuberculosis group(P＜0.05),the incidence of bronchiectatic shadow of the PPTB-NTMPD group was higher than that of the recurrent pulmonary tuberculosis group(P＜0.05).There were significant differences in the age,incidence of pleural thickening and incidence of COPD among the patients with different time intervals between ini-tial diagnosis of pulmonary tuberculosis and the diagnosis of NTMPD in the PPTB-NTMPD group(P＜0.05).CONCLUSIONS The previous pulmonary tuberculosis mainly affect the body mass index less than 18.5 kg/m2 and the post-tuberculosis pulmonary diseases such as cough,pulmonary cavity,emphysema,pulmonary bullae,COPD and damaged lung of the NTMPD patients.The NTMPD patients with previous pulmonary tuberculosis are more likely to have bronchiectasia than the patients with recurrent tuberculosis.It is necessary for the clinicians to attach great importance.

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 assess coronary microvascular obstruction(MVO)after percutaneous coronary intervention in(PCI)patients with acute ST-segment elevation myocardial infarction(STEMI)and to investigate its value for patient prognosis.Methods We enrolled 97 patients who were hospitalized for acute STEMI at Wuhan Asia Heart Hospital from May 2021 to June 2024,underwent emergency PCI during hospitalization,and completed cardiac magnetic resonance(CMR)at a median of 7(5,8)days after the procedure.Patients were classified into MVO group(n=58)and non-MVO group(n=39)according to the results of CMR.Cox regression was used to analyse predictors of adverse events after PCI.Patients were followed for a median of 11.5(8.5,24.5)months for the occurrence of major adverse cardiovascular events(MACE,a composite outcome including readmission for heart failure,recurrent myocardial infarction,target vessel restenosis,target vessel revascularisation,and cardiac death)and secondary endpoint events(left ventricular remodelling,non-cardiac death).Results MVO was evidenced in 58 patients(59.79％).Multifactorial Cox regression analysis showed that MVO(HR 7.024,95％CI 1.408-35.027,P=0.017)and the proportion of inactive myocardium to the left ventricle(HR 1.066,95％CI 1.014-1.121,P=0.012)were the independent predictors factors for the incidence of adverse events in STEMI patients after PCI.The median follow-up time was 11.5(8.5,24.5)months.There was no statistically significant difference in the incidence of MACE between the MVO group and the non-MVO group(P=0.347).However,the MVO group had a higher incidence of secondary endpoints(32.76％ vs.2.56％,P＜0.001)and a higher incidence of left ventricular remodeling(29.31％ vs.2.56％,P＜0.001).Kaplan Meier survival analysis showed that the prognosis of the non-MVO group was significantly better than that of the MVO group(Log-rank P＜0.001).Conclusions MVO after PCI in patients with acute STEMI is a good predictor of clinical prognosis.

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.