Diabetic retinopathy(DR)is one of the most common and serious microvascular complications of diabetes, posing a significant threat to patients' visual health. In recent years, epigenetic mechanisms have garnered increasing attention in the scientific community for their pivotal role in the onset and progression of DR. This paper systematically examines the regulatory roles of epigenetic mechanisms in DR, covering key pathways such as DNA methylation, histone modifications, chromatin remodeling, and non-coding RNAs. Under hyperglycemic conditions in diabetes, these epigenetic mechanisms modulate gene expression, thereby influencing critical pathological processes such as oxidative stress, inflammatory responses, mitochondrial dysfunction, and metabolic memory. This article reviews recent advances in epigenetic regulation in DR, providing an in-depth analysis of its underlying molecular mechanisms and complex regulatory networks, and explores the potential of epigenetic markers as diagnostic biomarkers and therapeutic targets. Additionally, this article highlights emerging therapeutic strategies targeting epigenetic modifications, aiming to provide a theoretical foundation and research direction for the early diagnosis and precision treatment of this disease.

OBJECTIVE To investigate the mechanism of Zuogui pill in improving pancreatic β cell function in the offspring of rats with gestational diabetes mellitus （GDM）.METHODS Thirty-six pregnant rats were divided into normal group， model group， insulin glargine group （positive control）， and low-， medium- and high-dose Zuogui pill groups， with 6 rats in each group. The normal group and model group were given intragastric administration of equal-volume normal saline. The insulin glargine group was subcutaneously injected with insulin glargine at an initial dose of 1 U/kg， and the dosage was increased by 1 U per day until random blood glucose returned to normal. The low-， medium- and high-dose Zuogui pill groups were intragastrically administered with Zuogui pill solutions at 4.725， 9.45 and 18.9 g/kg once a day until the birth of offspring. On postnatal day 21 （12 offspring in each group）， body weight， fasting blood glucose （FBG） and oral glucose tolerance test were performed on the offspring. Pancreatic histopathological changes of 60-day-old offspring were observed. The insulin-positive expression area ratio in pancreatic tissue， serum levels of glycated serum protein （GSP）， high-density lipoprotein cholesterol （HDL-C） and low-density lipoprotein cholesterol （LDL-C）， as well as the mRNA and protein relative expression levels of wingless-type MMTV integration site family member 7a（Wnt7a）and glycogen synthase kinase 3β（GSK-3β） in pancreatic tissue were detected.RESULTS Compared with normal group， the body weight， insulin-positive expression area ratio in pancreatic tissue， serum HDL-C level， and the mRNA and protein relative expression levels of Wnt7a in pancreatic tissue were significantly decreased of the offspring in the model group （ P ＜0.05）. Meanwhile， FBG， blood glucose levels at 60， 90 and 120 min after intragastric administration of 20% glucose solution， serum GSP and LDL-C levels， as well as the mRNA and protein relative expression levels of GSK-3β in pancreatic tissue were significantly increased （ P ＜0.05）；mild degeneration and necrosis of islet cells were observed in pancreatic tissue. Compared with the model group， the above-mentioned indexes were significantly reversed in medium- and high-dose Zuogui pill groups （ P ＜0.05）， and pancreatic pathological injury was improved to varying degrees.CONCLUSIONS Zuogui pill may restore the homeostasis of Wnt7a/GSK-3β signaling axis， so as to improve pancreatic β cell function in the offspring of GDM rats.

From the perspective of narrative medicine， focusing on the “three focal points，” integrating the “three elements，” and grounding in the “four relationships，” this study employed a close reading framework of “metaphor， time， space， and voice” to conduct a detailed interpretation on the approach and methodology of the medical narrative in the classic traditional Chinese medical case record Yi’s Medical Case. The close reading revealed that the author of the case record， Yi Dagen， demonstrated exceptional sensitivity to time and space. He excelled in tracing the complete process of disease occurrence and development within the natural rhythms of life， and in discerning the full truth of disease within the unified “body-society-nature” heaven-human field. When facing different subjects in diagnosis and treatment， Yi Dagen consistently rejected one-way knowledge inculcation and instead chose egalitarian dialogue. He was particularly adept at using metaphorical tools to embed obscure medical theories into patients’ disease stories through the form of life experience， thereby building shared medical understanding among different subjects and achieving the “co-creation of meaning” of disease stories. Through a reflective representation of the findings from the close reading， it was argued that Yi Dagen’s diagnostic and therapeutic narrative logic of “pulse-pattern-symptom-treatment” and the metaphorical narrative possessing dual functions of ontological cognition and an interpretive tool were an important means for fostering empathy and facilitating healing， as well as a concentrated manifestation of Yi Dagen’s “patient-centered” medical attitude. Analyzing Yi Dagen’s sophisticated narrative strategies and techniques provides wisdom references for cultivating medical staff’s narrative competence and offers historical insights for the localized development of narrative medicine.

Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

Objective:To investigate the safety and efficacy of urinary microbiota transplantation（UMT）in treating interstitial cystitis（IC）.Methods:A retrospective analysis of the clinical data of three patients with IC treated with UMT at the Central Hospital of Jiangnan University from May 2022 to August 2024. Three women（45，62，79 years）presented with urinary frequency（10 - 90 min intervals），urgency，dysuria，lower abdominal pain，and non-organic sleep disorder，with nocturia（2 - 15 episodes）causing sleep difficulty. Disease durations were 3，6，and 21 years. Prior antibiotic therapy failed. Preoperative urinalysis/culture（x2）ruled out bacterial cystitis，and diagnosed as interstitial cystitis（IC），with one of transient positive urine culture. Preoperative scores for case 1 were self-rating depression scale（SDS）of 49，self-rating anxiety scale（SAS）of 31，interstitial cystitis symptom index（ICSI）of 5，interstitial cystitis problem index（ICPI）of 2，brief urological problem scale of 50，genitourinary pain assessment scale of 10，and pain catastrophizing scale（PCS）of 0. For case 2，the scores were 60 of SDS，66 of SAS，9 of ICSI，11 of ICPI，50 of brief urological problem scale，28 of genitourinary pain assessment scale，and 34 of PCS. For case 3，the scores were 44 of SDS，48 of SAS，11 of ICSI，5 of ICPI，33 of brief urological problem scale，27 of genitourinary pain assessment scale，and 21 of PCS. Preoperative bladder hydro-distention showed mucosal hemorrhage including central block hemorrhage（Case 1），numerous spots（Case 2），and distinct sheets（Case 3）. Preoperative urine 16S rRNA sequencing revealed low diversity，increased Gardnerella/ Bacteroides（opportunistic），and decreased Bacillus/ Streptococcus（beneficial）. Two healthy young female donors had normal comprehensive tests covering blood/urine/stool，coagulation，CRP，immunity，liver/kidney function，lipids，infectious diseases，hormones，tumor markers，urine culture，TOUCH，and expanded quantitative urine culture. Donor urine 16S rRNA showed low pathogenic（ Gardnerella/ Bacteroides）abundance. Donor midstream morning urine was catheter-collected，centrifuged，and the bacterial pellet resuspended in saline. Recipients underwent bladder irrigation pre-UMT. On UMT day，donor bacterial suspension was instilled via catheter with adverse event monitoring. Follow-up included clinic visits at 1 month and 1 year for symptom assessment，scale scoring，cystoscopy evaluating mucosal inflammation，hydrodistension checks，and telephone tracking of urinary symptoms every 2 - 3 months. Prognosis was assessed by symptom relief，scale score reduction，and mucosal recovery. Results:No adverse reactions occurred within 24 hours post-UMT in all 3 cases. Two patients showed same-day urinary urgency reduction；three reported relief from urinary frequency/urgency on postoperative day 7，with 2 - 3 hour daytime intervals and 0 - 5 nocturnal voids. Two patients experienced lower abdominal pain alleviation. Postoperative Week 1 urinalysis and urine cultures revealed no abnormalities. The 16S rRNA test showed a decrease in the abundance of harmful bacteria（e.g.， Cupriavidus，Ureaplasm，Mycobacterium，Pseudomonas）and an increase in the abundance of beneficial bacteria（ Dietzia，Halomonas，and Streptococcus），and the overall urobacterial structure was significantly improved and similar to that of the donor. Case 1 was followed up for 20 months，and the lab tests were normal，with SDS scales of 38，SAS of 20，ICSI of 3，ICPI of 2，brief urological problem scale of 44，genitourinary pain assessment scale of 10，PCS of 0，at 9 months post-op follow-up，indicating physical and mental improvement. The bladder hydro-distention revealed intact mucosa with only mild inflammation，which improved versus preoperative situation. Case 2 was followed up for 15 months，and the lab tests were normal，with SDS scales of 44，SAS of 34，ICSI of 4，ICPI of 2，brief scale of urinary problems of 0，genitourinary pain assessment scale of 9，PCS of 7，at 2 months post-op follow-up，showing improved anxiety/depression and quality of life. The hydro-distention showed decreased scattered hemorrhagic dots and mucosal inflammation. Case 3 was followed up for 13 months，with an increased leukocytes of urine and the other being normal for lab tests，and SDS scales of 35，SAS of 46，ICSI of 13，ICPI of 13，brief scale of urinary problems of 10，genitourinary pain assessment scale of 33，PCS of 11，at 13 months post-op follow-up，indicating physical and mental improvement. The hydro-distention revealed mucosal congestion，marked submucosal vasodilation，and inflammation decreased compared with preoperative situation. Conclusions:UMT alleviates urinary frequency，urgency，and pain in IC patients with sustained effects，significantly improves urine microecology，and shows no adverse events，positioning it as a viable intervention for IC.

Objective:To report the nationwide surveillance results of pathogenic profiles and antimicrobial resistance patterns of Gram-positive bloodstream infections in China in 2023.Methods:The clinical isolates of Gram-posttive bacteria from blood cultures were collected in member hospitals of National Bloodstream Infection Bacterial Resistant Investigation Collaborative System（BRICS）during January to December 2023. Antimicrobial susceptibility testing was performed using the dilution method recommended by the Clinical and Laboratory Standards Institute（CLSI）. Statistical analyses were conducted using WHONET 5.6 and SPSS 25.0 software.Results:A total of 4 385 Gram-positive bacterial isolates were obtained from 60 participating center. The top five pathogens were Staphylococcus aureus（ n=1 544，35.2%），coagulase-negative Staphylococci（ n=1 441，32.9%）， Enterococcus faecium（ n=574，13.1%）， Enterococcus faecalis（ n=385，8.8%），and α-hemolytic Streptococci（ n=187，4.3%）. The prevalence of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）was 26.2%（405/1 544）and 69.8%（1 006/1 441），respectively. Notably，all Staphylococci remained susceptible to glycopeptide or daptomycin. Staphylococcus aureus demonstrated excellent susceptibility（>97.0%）to cephalobiol，rifampicin，trimethoprim-sulfamethoxazole，linezolid，minocycline，tigecycline，and eravacycline. No Enterococcus exhibiting resistance to linezolid were detected. Glycopeptide resistance was uncommon but more frequent in Enterococcus faecium（resistance to vancomycin and teicoplanin：both 1.7%）compared to Enterococcus faecalis（both 0.3%）. The detection rates of MRSA and MRCNS exhibited significant regional variations across the country（ χ2=17.674 and 148.650，respectively，both P<0.001）. No vancomycin-resistant Enterococci were detected in central China. Institutional comparison demonstrated higher prevalence of MRSA（ χ2=14.111， P<0.001）and MRCNS（ χ2=4.828， P=0.028）in provincial hospitals than that in municipal hospitals. Socioeconomic analysis identified elevated detection rates of both MRSA（ χ2=18.986， P<0.001）and MRCNS（ χ2=4.477， P=0.034）in less developed regions（per capita GDP

Objective:To report the results of bacterial resistant investigation collaborative system（BRICS）on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2023，and provide reference for clinical tretment of bloodstream infections and prevention and control of bacterial resistance.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of BRICS were collected during January 2023 to December 2023. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 were used to analyze the data.Results:During the study period，11 492 strains of Gram-negative bacteria were collected from 60 hospitals，of which 10 098（87.9%）were Enterobacterales and 1 394（12.1%）were non-fermentative bacteria. The top 5 bacterial species were Escherichia coli（50.0%）， Klebsiella pneumoniae（26.1%）， Pseudomonas aeruginosa（5.1%）， Acinetobacter baumannii complex（5.0%）and Enterobacter cloacae complex（4.1%）. The ESBL-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus mirablilis were 46.8%（2 685/5 741），18.3%（549/2 999）and 44.0%（77/175），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（76/5 741）and 15.0%（450/2 999）；32.9%（25/76）and 78.0%（351/450）of CREC and CRKP were sensitive to ceftazidime/avibactam combination，respectively. 94.7%（72/76）and 90.2%（406/450）of CREC and CRKP were sensitive to aztreonam/avibactam combination. Furthermore，57.9%（44/76）and 79.1%（356/450）were sensitive to imipenem/relebactam combination. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 64.6%（370/573），while more than 80.0% of CRAB complex was sensitive to tigecycline，eravacycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 17.0%（99/581）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of important Gram-negative bacteria resistance among different regions in China，with statistically significant differences in the prevalence of CREC，CRKP，CRPA and CRAB complex（ χ2=10.6，28.6，10.8 and 19.3， P<0.05）. The prevalence of ESBL-producing Escherichia coli， CREC，CRAB complex and CRKP were higher in provincial hospitals than those in municipal hospitals（ χ2=12.5，9.8，12.7 and 57.8，all P<0.01）. Conclusions:Gram-negative bacteria are the main pathogens causing bloodstream infections in China，and Escherichia coli is ranked in the top，while the trend of Klebsiella pneumoniae increases continuously with time. CRKP infection shows a slow upward trend，CREC infecton maintains a low prevalence level，and CRAB complex infection continues to exhibit a high prevalence rate. The composition and resistance patterns of pathogens causing bloodstream infections vary to some extent across different regions and levels of hospitals in China.

Objective:To investigate the safety and efficacy of urinary microbiota transplantation（UMT）in treating interstitial cystitis（IC）.Methods:A retrospective analysis of the clinical data of three patients with IC treated with UMT at the Central Hospital of Jiangnan University from May 2022 to August 2024. Three women（45，62，79 years）presented with urinary frequency（10 - 90 min intervals），urgency，dysuria，lower abdominal pain，and non-organic sleep disorder，with nocturia（2 - 15 episodes）causing sleep difficulty. Disease durations were 3，6，and 21 years. Prior antibiotic therapy failed. Preoperative urinalysis/culture（x2）ruled out bacterial cystitis，and diagnosed as interstitial cystitis（IC），with one of transient positive urine culture. Preoperative scores for case 1 were self-rating depression scale（SDS）of 49，self-rating anxiety scale（SAS）of 31，interstitial cystitis symptom index（ICSI）of 5，interstitial cystitis problem index（ICPI）of 2，brief urological problem scale of 50，genitourinary pain assessment scale of 10，and pain catastrophizing scale（PCS）of 0. For case 2，the scores were 60 of SDS，66 of SAS，9 of ICSI，11 of ICPI，50 of brief urological problem scale，28 of genitourinary pain assessment scale，and 34 of PCS. For case 3，the scores were 44 of SDS，48 of SAS，11 of ICSI，5 of ICPI，33 of brief urological problem scale，27 of genitourinary pain assessment scale，and 21 of PCS. Preoperative bladder hydro-distention showed mucosal hemorrhage including central block hemorrhage（Case 1），numerous spots（Case 2），and distinct sheets（Case 3）. Preoperative urine 16S rRNA sequencing revealed low diversity，increased Gardnerella/ Bacteroides（opportunistic），and decreased Bacillus/ Streptococcus（beneficial）. Two healthy young female donors had normal comprehensive tests covering blood/urine/stool，coagulation，CRP，immunity，liver/kidney function，lipids，infectious diseases，hormones，tumor markers，urine culture，TOUCH，and expanded quantitative urine culture. Donor urine 16S rRNA showed low pathogenic（ Gardnerella/ Bacteroides）abundance. Donor midstream morning urine was catheter-collected，centrifuged，and the bacterial pellet resuspended in saline. Recipients underwent bladder irrigation pre-UMT. On UMT day，donor bacterial suspension was instilled via catheter with adverse event monitoring. Follow-up included clinic visits at 1 month and 1 year for symptom assessment，scale scoring，cystoscopy evaluating mucosal inflammation，hydrodistension checks，and telephone tracking of urinary symptoms every 2 - 3 months. Prognosis was assessed by symptom relief，scale score reduction，and mucosal recovery. Results:No adverse reactions occurred within 24 hours post-UMT in all 3 cases. Two patients showed same-day urinary urgency reduction；three reported relief from urinary frequency/urgency on postoperative day 7，with 2 - 3 hour daytime intervals and 0 - 5 nocturnal voids. Two patients experienced lower abdominal pain alleviation. Postoperative Week 1 urinalysis and urine cultures revealed no abnormalities. The 16S rRNA test showed a decrease in the abundance of harmful bacteria（e.g.， Cupriavidus，Ureaplasm，Mycobacterium，Pseudomonas）and an increase in the abundance of beneficial bacteria（ Dietzia，Halomonas，and Streptococcus），and the overall urobacterial structure was significantly improved and similar to that of the donor. Case 1 was followed up for 20 months，and the lab tests were normal，with SDS scales of 38，SAS of 20，ICSI of 3，ICPI of 2，brief urological problem scale of 44，genitourinary pain assessment scale of 10，PCS of 0，at 9 months post-op follow-up，indicating physical and mental improvement. The bladder hydro-distention revealed intact mucosa with only mild inflammation，which improved versus preoperative situation. Case 2 was followed up for 15 months，and the lab tests were normal，with SDS scales of 44，SAS of 34，ICSI of 4，ICPI of 2，brief scale of urinary problems of 0，genitourinary pain assessment scale of 9，PCS of 7，at 2 months post-op follow-up，showing improved anxiety/depression and quality of life. The hydro-distention showed decreased scattered hemorrhagic dots and mucosal inflammation. Case 3 was followed up for 13 months，with an increased leukocytes of urine and the other being normal for lab tests，and SDS scales of 35，SAS of 46，ICSI of 13，ICPI of 13，brief scale of urinary problems of 10，genitourinary pain assessment scale of 33，PCS of 11，at 13 months post-op follow-up，indicating physical and mental improvement. The hydro-distention revealed mucosal congestion，marked submucosal vasodilation，and inflammation decreased compared with preoperative situation. Conclusions:UMT alleviates urinary frequency，urgency，and pain in IC patients with sustained effects，significantly improves urine microecology，and shows no adverse events，positioning it as a viable intervention for IC.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-negative bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-negative bacteria from blood cultures in member hospitals of national bloodstream infection Bacterial Resistant Investigation Collaborative System（BRICS）were collected during January 2022 to December 2022. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical and Laboratory Standards Institute（CLSI）. WHONET 5.6 and SPSS 25.0 software were used to analyze the data.Results:During the study period，9 035 strains of Gram-negative bacteria were collected from 51 hospitals，of which 7 895（87.4%）were Enterobacteriaceae and 1 140（12.6%）were non-fermenting bacteria. The top 5 bacterial species were Escherichia coli（ n=4 510，49.9%）， Klebsiella pneumoniae（ n=2 340，25.9%）， Pseudomonas aeruginosa（ n=534，5.9%）， Acinetobacter baumannii complex（ n=405，4.5%）and Enterobacter cloacae（ n=327，3.6%）. The ESBLs-producing rates in Escherichia coli， Klebsiella pneumoniae and Proteus spp. were 47.1%（2 095/4 452），21.0%（427/2 033）and 41.1%（58/141），respectively. The prevalence of carbapenem-resistant Escherichia coli（CREC）and carbapenem-resistant Klebsiella pneumoniae（CRKP）were 1.3%（58/4 510）and 13.1%（307/2 340）；62.1%（36/58）and 9.8%（30/307）of CREC and CRKP were resistant to ceftazidime/avibactam combination，respectively. The prevalence of carbapenem-resistant Acinetobacter baumannii（CRAB）complex was 59.5%（241/405），while less than 5% of Acinetobacter baumannii complex was resistant to tigecycline and polymyxin B. The prevalence of carbapenem-resistant Pseudomonas aeruginosa（CRPA）was 18.4%（98/534）. There were differences in the composition ratio of Gram-negative bacteria in bloodstream infections and the prevalence of main Gram-negative bacteria resistance among different regions，with statistically significant differences in the prevalence of CRKP and CRPA（ χ2=20.489 and 20.252， P<0.001）. The prevalence of CREC，CRKP，CRPA，CRAB，ESBLs-producing Escherichia coli and Klebsiella pneumoniae were higher in provinicial hospitals than those in municipal hospitals（ χ2=11.953，81.183，10.404，5.915，12.415 and 6.459， P<0.01 or <0.05），while the prevalence of CRPA was higher in economically developed regions（per capita GDP ≥ 92 059 Yuan）than that in economically less-developed regions（per capita GDP <92 059 Yuan）（ χ2=6.240， P=0.012）. Conclusions:The proportion of Gram-negative bacteria in bloodstream infections shows an increasing trend，and Escherichia coli is ranked in the top，while the trend of CRKP decreases continuously with time. Decreasing trends are noted in ESBLs-producing Escherichia coli and Klebsiella pneumoniae. Low prevalence of carbapenem resistance in Escherichia coli and high prevalence in CRAB complex have been observed. The composition ratio and antibacterial spectrum of bloodstream infections in different regions of China are slightly different，and the proportion of main drug resistant bacteria in provincial hospitals is higher than those in municipal hospitals.