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.

Catheter-based pulsed field ablation(PFA)for atrial fibrillation ablation has been widely adopted worldwide in recent years,accumulating substantial evidence for its efficacy and safety.However,several adverse events associated with this technology have also been observed,such as PFA-related coronary artery spasm,hemolysis,acute renal injury,and symptomatic or asymptomatic cerebrovascular events.This review summarizes the latest basic and clinical research advances in PFA over the past two years,focusing on biophysical aspects including the field intensity of PFA,the thermal effects of PFA,contact force,and the number of applications.We discuss whether PFA demonstrates tissue selectivity,the mechanisms of hemolysis and microbubble formation,as well as the lesion morphology and impact factors to lesion depth.This review aims to provide clinicians with a more in-depth understanding of PFA technology and biphasic to optimize clinical application.

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 explore the efficacy of arthroscopic reduction combined with percutaneous screw fixation in the treatment of Sanders types Ⅱ and Ⅲ calcaneal fractures.Methods Forty-eight patients with Sanders types Ⅱ and Ⅲcalcaneal fractures were divided into the arthroscopic reduction combined with percutaneous screw fixation(arthroscopy)group(n=23)and the tarsal sinus approach open reduction combined with screw internal fixation(tarsal sinus approach)group(n=25)according to different surgical methods and plans.The operative time,incision length,postoperative complications and secondary removal of internal fixation were compared between the two groups.Changes in B?hler's angle and Gissane's angle were evaluated and compared between the two groups at 3 months,6 months after operation and at the last follow-up.Additionally,the American Orthopaedic Foot&Ankle Society(AOFAS)ankle-hindfoot score and the visual analog scale(VAS)for pain were used to assess outcomes at the last follow-up.Results Compared with the tarsal sinus approach group,the incision length was reduced,the operation time was prolonged and the incidence of complications was decreased in the arthroscopic group(P＜0.05).At 3 months,6 months after the operation and the last follow-up,there were no significant differences in the B?hler Angle,Gissanes Angle,AOFAS and VAS scores between the arthroscopic group and the tarsal sinus approach group(P＞0.05).Conclusion Both groups of regimens can enable patients to achieve good postoperative therapeutic efficacy.However,under arthroscopic assistance,surgical incisions inherently possess minimally invasive advantages,while the incidence of postoperative complications is lower compared to the sinus tarsi approach.

Objective To analyze the CT manifestations of high altitude pulmonary edema(HAPE)to provide radiological evidence for its early and accurate diagnosis.Methods Totally 200 HAPE patients clinically confirmed at some hospital from April 2021 to April 2024 were enrolled into a study group,and 56 individuals undergoing health examinations at the hospital's physical examination center between January and June 2023 were included into a control group.Examinations were carried out with a United Imaging uCT528 40-slice spiral CT scanner.The patients in the study group were observed in terms of HAPE staging,the extent of pulmonary involvement,CT manifestations of different stages including location,distribution,density and morphology of pulmonary lesion.The diameters of the main pulmonary arteries and ascending aortas of the subjects in the two groups were measured,and the ratios of the two diameters were calculated.SPSS 25.0 software was used for statistical analysis.Results In the study group,there were 26 cases(13.0%)at early stage,105 ones at progression stage(52.5%),32 ones at critical outbreak stage(16.0%)and 37 ones at resolution and absorption stage(18.5%),and there were 35.5%with unilateral lung involvement and 64.5%with bilateral involvement.At early stage,HAPE chest CT manifestations included increased and thickened bilateral bronchovascular bundles,widened main pulmonary artery lumen and faint ground-glass opacity in lungs;at progression stage,HAPE chest CT manifestations revealed multiple cloud-like or patchy areas of increased density within lungs;at critical outbreak stage,CT scanning indicated diffuse patchy opacities and consolidation in lungs,white lung-like changes could be found in some severe cases,and bronchial air signs were shown within affected segments in some ones with severer signs in the right lung than in the left lung;at resolution and absorption stage the CT manifestations were similar to those at early stage,with lesions completely resolving after treatment.The study group had the diameters of the main pulmonary arteries greater while the diameters of the ascending aortas less than those of the control group,and the ratios of the diameters of the two diameters in the study group were higher than those in the control group,with the differences being statistically significant(all P<0.05).Conclusion Chest CT is an important examination method for the early diagnosis of HAPE and clarification of its clinical staging,which directly reflects the pulmonary pathological changes in HAPE patients and helps doctors fully understand the disease progression.

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 explore the efficacy of arthroscopic reduction combined with percutaneous screw fixation in the treatment of Sanders types Ⅱ and Ⅲ calcaneal fractures.Methods Forty-eight patients with Sanders types Ⅱ and Ⅲcalcaneal fractures were divided into the arthroscopic reduction combined with percutaneous screw fixation(arthroscopy)group(n=23)and the tarsal sinus approach open reduction combined with screw internal fixation(tarsal sinus approach)group(n=25)according to different surgical methods and plans.The operative time,incision length,postoperative complications and secondary removal of internal fixation were compared between the two groups.Changes in B?hler's angle and Gissane's angle were evaluated and compared between the two groups at 3 months,6 months after operation and at the last follow-up.Additionally,the American Orthopaedic Foot&Ankle Society(AOFAS)ankle-hindfoot score and the visual analog scale(VAS)for pain were used to assess outcomes at the last follow-up.Results Compared with the tarsal sinus approach group,the incision length was reduced,the operation time was prolonged and the incidence of complications was decreased in the arthroscopic group(P＜0.05).At 3 months,6 months after the operation and the last follow-up,there were no significant differences in the B?hler Angle,Gissanes Angle,AOFAS and VAS scores between the arthroscopic group and the tarsal sinus approach group(P＞0.05).Conclusion Both groups of regimens can enable patients to achieve good postoperative therapeutic efficacy.However,under arthroscopic assistance,surgical incisions inherently possess minimally invasive advantages,while the incidence of postoperative complications is lower compared to the sinus tarsi approach.

Objective To analyze the CT manifestations of high altitude pulmonary edema(HAPE)to provide radiological evidence for its early and accurate diagnosis.Methods Totally 200 HAPE patients clinically confirmed at some hospital from April 2021 to April 2024 were enrolled into a study group,and 56 individuals undergoing health examinations at the hospital's physical examination center between January and June 2023 were included into a control group.Examinations were carried out with a United Imaging uCT528 40-slice spiral CT scanner.The patients in the study group were observed in terms of HAPE staging,the extent of pulmonary involvement,CT manifestations of different stages including location,distribution,density and morphology of pulmonary lesion.The diameters of the main pulmonary arteries and ascending aortas of the subjects in the two groups were measured,and the ratios of the two diameters were calculated.SPSS 25.0 software was used for statistical analysis.Results In the study group,there were 26 cases(13.0%)at early stage,105 ones at progression stage(52.5%),32 ones at critical outbreak stage(16.0%)and 37 ones at resolution and absorption stage(18.5%),and there were 35.5%with unilateral lung involvement and 64.5%with bilateral involvement.At early stage,HAPE chest CT manifestations included increased and thickened bilateral bronchovascular bundles,widened main pulmonary artery lumen and faint ground-glass opacity in lungs;at progression stage,HAPE chest CT manifestations revealed multiple cloud-like or patchy areas of increased density within lungs;at critical outbreak stage,CT scanning indicated diffuse patchy opacities and consolidation in lungs,white lung-like changes could be found in some severe cases,and bronchial air signs were shown within affected segments in some ones with severer signs in the right lung than in the left lung;at resolution and absorption stage the CT manifestations were similar to those at early stage,with lesions completely resolving after treatment.The study group had the diameters of the main pulmonary arteries greater while the diameters of the ascending aortas less than those of the control group,and the ratios of the diameters of the two diameters in the study group were higher than those in the control group,with the differences being statistically significant(all P<0.05).Conclusion Chest CT is an important examination method for the early diagnosis of HAPE and clarification of its clinical staging,which directly reflects the pulmonary pathological changes in HAPE patients and helps doctors fully understand the disease progression.

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.