Objective:To explore the prognostic value of peripheral blood lymphocyte subsets in patients with newly diagnosed multiple myeloma (NDMM) .Methods:The study retrospectively analyzed 133 patients with NDMM admitted to the General Hospital of Tianjin Medical University General Hospital between 2017 and 2022. The least absolute shrinkage and selection operator (LASSO) regression was used to screen the predictive subgroups from the peripheral blood lymphocyte subsets, and the optimal cutoff value was calculated through receiver operating characteristic curve analysis. A nomogram was constructed based on the results of the multiple-factor analysis, and the predictive performance of the nomogram was evaluated by the concordance index and calibration curve. Kaplan-Meier curves and log-rank tests were conducted to compare the differences in overall survival (OS) and progression-free survival between the high-risk and low-risk immune risk scores groups.Results:Using LASSO regression, the percentages and absolute counts of CD16 +CD56 + NK cells, CD3 + T lymphocytes, CD3 +CD8 + T lymphocytes, and CD3 -CD19 + B lymphocytes were selected as predictive subgroups. The immune risk score of patients with NDMM was calculated based on the coefficients of each lymphocyte subgroup. The area under the curve of the immune risk score was 0.737, and the optimal cutoff value was -1.834. Based on this, the patients were divided into high-risk and low-risk groups. Survival analysis showed a significant difference in the 3-year OS rate between the high-risk and low-risk immune risk score groups (87.4% vs 49.0%, P<0.001), and a significant difference in the 3-year OS rate between the high-risk and low-risk immune risk score groups in patients with minimal residual disease negative (100% vs 68.6%, P=0.001). Multivariate analysis showed that serum calcium ( P=0.034), high-risk cytogenetic abnormalities ( P=0.002), and immune risk score ( P<0.001) were prognostic factors for patients with NDMM, and a nomogram was constructed based on these factors. The consistency index of the nomogram was 0.793, and the calibration curve showed good predictive ability. The nomogram can accurately classify the risk of different prognostic staging systems. Conclusions:The combined analysis of lymphocyte subsets in the peripheral blood has an important value in predicting the prognosis of patients with NDMM.

Objective:To compare the the cultivation effects of human embryos in dry and humid incubators.Methods:A total of 479 infertile patients who underwent in vitro fertilization (IVF) treatment at Reproductive Center of Guiyang Maternal and Child Health Care Hospital from October 2020 to April 2022. The study was divided into two stages. The first stage of the study was a self-comparative research with 95 cases from the same period and source. The embryos were divided into dry and humid incubator groups to compare the embryo development indicators. In the second stage of the study, the patients were divided into six groups, including 10 μL humid incubator group ( n=64), 20 μL humid incubator group ( n=64), 30 μL humid incubator group ( n=64), 10 μL dry incubator group ( n=64), 20 μL dry incubator group ( n=64), and 30 μL dry incubator group ( n=64). The general clinical data, embryo development indicators, pregnancy outcomes, and the osmotic pressure and pH values of each group at 24 h, 48 h and 72 h were detected and compared. Results:After cultivation of the same patient's embryos in dry and humid incubator, the total blastocyst formation rate [62.3% (162/260)] and high-quality blastocyst rate [24.6% (64/260)] in dry incubator were lower than those in the humid incubator [71.6% (252/352), P=0.015; 32.1% (113/352), P=0.043]. Compared with the other microdroplet groups, the osmotic pressure of cleavage culture medium in 10 μL group of dry incubator at 48 h and 72 h and blastocyst culture medium were significantly increased, the differences among the groups were significant (cleavage culture medium, all P<0.001; blastocyst culture medium, P=0.006, P=0.008). There was no significant difference in pH value among different microdroplet volume groups at the same period (all P>0.05). There were no significant differences in general data among the different microdroplet groups (all P>0.05). Compared with the other microdroplet groups, 10 μL dry incubator group exhibited significantly lower transferable embryo rate (all P<0.001). When compared with 20 μL and 30 μL groups in both dry and humid incubators, 10 μL dry incubator group showed a lower day 5 blastocyst formation rate, lower total blastocyst formation rate, and lower high-quality blastocyst formation rate, the differences among the groups were significant (all P<0.05). There were no significant differences in the number of transferred embryos, the ratio of cleavage-stage embryos and the ratio of high-quality embryos among different groups (all P>0.05). Compared with the other microdroplet groups, the clinical pregnancy rate, the embryo implantation rate, the live birth rate of fresh transplanted embryos and the cumulative pregnancy rate in 10 μL group in the dry incubator decreased, and the miscarriage rate increased, but all were not significant (all P>0.05). Conclusion:Compared with humid incubators, there are no significant differences in embryo development and pregnancy outcomes for droplet volumes of 20 μL or above in dry incubators. However, the 10 μL microdroplet culture in the dry incubator is not conducive to embryonic development, which may be related to the increased osmotic pressure of the microdroplet.

Objective To investigate the expression and clinical significance of serum Golgi protein 73 (GP73) and SMAD family member 2 (SMAD2)in endometriosis. Methods From March 2022 to September 2023,175 patients with endometriosis who visited Xinjiang Military Region General Hospital were collected as the observation group. According to the staging of endometriosis,patients were separated into mild group (stage Ⅰ,n=61),moderate group (stage Ⅱ,n=52 ) and severe group (stage Ⅲ-Ⅳ,n=62). The healthy group comprised 55 healthy individuals who underwent medical examinations from December 2020 to December 2022 at Xinjiang Military Region General Hospital. ELISA was applied to detect serum GP73 and SMAD2 levels,the general data of the observation group and the control group were compared. Logistic regression was used to analyze the relevant factors affecting the occurrence of endometriosis,the Pearson method was applied to investigate the correlation between serum GP73 and SMAD2 levels in patients with endometriosis.ROC curves were used to assess the diagnostic value of serum GP73,SMAD2 levels and their combination in patients with EMT. Results The presence or absence of dysmenorrhea and irregular menstruation was compared between the two groups,and the differences were statistically significant (x2=17.633,39.268,all P<0.001). Serum GP73 (73.68±19.23 ng/ml),SMAD2 (42.27±9.61 mg/L) expression levels in the observation group were higher than those in the control group (58.61±13.27 ng/ml,35.26±6.37 mg/L),and the differences were statistically significant (t=8.327,7.845,all P<0.05). GP73 (59.79±17.26,73.73±18.17,87.29±22.05ng/ml) and SMAD2 (35.18±7.39,39.97±9.45,51.17±11.96mg/L) increased sequentially in the mild,moderate and severe groups,and the differences were statistical significance (F=31.067,42.866,all P<0.05). Pearson analysis showed serum GP73 levels were positively correlated with SMAD2 levels in EMT patients (r=0.427,P<0.001).Multifactorial Logistic regression analysis showed that irregular menstruation,dysmenorrhea,serum GP73[OR(95％CI):2.035 (1.208～3.428)],SMAD2[OR(95％CI):1.972 (1.284～3.029)]levels were risk factors for the development of EMT in patients (all P<0.05). The AUC(95％CI) for the combined diagnosis of EMT by serum GP73 and SMAD2 was 0.821 (0.776～0.861),which was higher than that of serum GP73 and SMAD2 alone[0.763 (0.714～0.807),0.708 (0.656～0.756)],respectively,and the differences were statistically significant (Z=3.121,4.346,all P<0.05). Conclusion Elevated serum GP73 and SMAD2 levels in EMT patients are all related to the extent of the patient's condition and have some diagnostic value for EMT.

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 compare the the cultivation effects of human embryos in dry and humid incubators.Methods:A total of 479 infertile patients who underwent in vitro fertilization (IVF) treatment at Reproductive Center of Guiyang Maternal and Child Health Care Hospital from October 2020 to April 2022. The study was divided into two stages. The first stage of the study was a self-comparative research with 95 cases from the same period and source. The embryos were divided into dry and humid incubator groups to compare the embryo development indicators. In the second stage of the study, the patients were divided into six groups, including 10 μL humid incubator group ( n=64), 20 μL humid incubator group ( n=64), 30 μL humid incubator group ( n=64), 10 μL dry incubator group ( n=64), 20 μL dry incubator group ( n=64), and 30 μL dry incubator group ( n=64). The general clinical data, embryo development indicators, pregnancy outcomes, and the osmotic pressure and pH values of each group at 24 h, 48 h and 72 h were detected and compared. Results:After cultivation of the same patient's embryos in dry and humid incubator, the total blastocyst formation rate [62.3% (162/260)] and high-quality blastocyst rate [24.6% (64/260)] in dry incubator were lower than those in the humid incubator [71.6% (252/352), P=0.015; 32.1% (113/352), P=0.043]. Compared with the other microdroplet groups, the osmotic pressure of cleavage culture medium in 10 μL group of dry incubator at 48 h and 72 h and blastocyst culture medium were significantly increased, the differences among the groups were significant (cleavage culture medium, all P<0.001; blastocyst culture medium, P=0.006, P=0.008). There was no significant difference in pH value among different microdroplet volume groups at the same period (all P>0.05). There were no significant differences in general data among the different microdroplet groups (all P>0.05). Compared with the other microdroplet groups, 10 μL dry incubator group exhibited significantly lower transferable embryo rate (all P<0.001). When compared with 20 μL and 30 μL groups in both dry and humid incubators, 10 μL dry incubator group showed a lower day 5 blastocyst formation rate, lower total blastocyst formation rate, and lower high-quality blastocyst formation rate, the differences among the groups were significant (all P<0.05). There were no significant differences in the number of transferred embryos, the ratio of cleavage-stage embryos and the ratio of high-quality embryos among different groups (all P>0.05). Compared with the other microdroplet groups, the clinical pregnancy rate, the embryo implantation rate, the live birth rate of fresh transplanted embryos and the cumulative pregnancy rate in 10 μL group in the dry incubator decreased, and the miscarriage rate increased, but all were not significant (all P>0.05). Conclusion:Compared with humid incubators, there are no significant differences in embryo development and pregnancy outcomes for droplet volumes of 20 μL or above in dry incubators. However, the 10 μL microdroplet culture in the dry incubator is not conducive to embryonic development, which may be related to the increased osmotic pressure of the microdroplet.

Objective To investigate the expression and clinical significance of serum Golgi protein 73 (GP73) and SMAD family member 2 (SMAD2)in endometriosis. Methods From March 2022 to September 2023,175 patients with endometriosis who visited Xinjiang Military Region General Hospital were collected as the observation group. According to the staging of endometriosis,patients were separated into mild group (stage Ⅰ,n=61),moderate group (stage Ⅱ,n=52 ) and severe group (stage Ⅲ-Ⅳ,n=62). The healthy group comprised 55 healthy individuals who underwent medical examinations from December 2020 to December 2022 at Xinjiang Military Region General Hospital. ELISA was applied to detect serum GP73 and SMAD2 levels,the general data of the observation group and the control group were compared. Logistic regression was used to analyze the relevant factors affecting the occurrence of endometriosis,the Pearson method was applied to investigate the correlation between serum GP73 and SMAD2 levels in patients with endometriosis.ROC curves were used to assess the diagnostic value of serum GP73,SMAD2 levels and their combination in patients with EMT. Results The presence or absence of dysmenorrhea and irregular menstruation was compared between the two groups,and the differences were statistically significant (x2=17.633,39.268,all P<0.001). Serum GP73 (73.68±19.23 ng/ml),SMAD2 (42.27±9.61 mg/L) expression levels in the observation group were higher than those in the control group (58.61±13.27 ng/ml,35.26±6.37 mg/L),and the differences were statistically significant (t=8.327,7.845,all P<0.05). GP73 (59.79±17.26,73.73±18.17,87.29±22.05ng/ml) and SMAD2 (35.18±7.39,39.97±9.45,51.17±11.96mg/L) increased sequentially in the mild,moderate and severe groups,and the differences were statistical significance (F=31.067,42.866,all P<0.05). Pearson analysis showed serum GP73 levels were positively correlated with SMAD2 levels in EMT patients (r=0.427,P<0.001).Multifactorial Logistic regression analysis showed that irregular menstruation,dysmenorrhea,serum GP73[OR(95％CI):2.035 (1.208～3.428)],SMAD2[OR(95％CI):1.972 (1.284～3.029)]levels were risk factors for the development of EMT in patients (all P<0.05). The AUC(95％CI) for the combined diagnosis of EMT by serum GP73 and SMAD2 was 0.821 (0.776～0.861),which was higher than that of serum GP73 and SMAD2 alone[0.763 (0.714～0.807),0.708 (0.656～0.756)],respectively,and the differences were statistically significant (Z=3.121,4.346,all P<0.05). Conclusion Elevated serum GP73 and SMAD2 levels in EMT patients are all related to the extent of the patient's condition and have some diagnostic value for EMT.

Objective:To explore the prognostic value of peripheral blood lymphocyte subsets in patients with newly diagnosed multiple myeloma (NDMM) .Methods:The study retrospectively analyzed 133 patients with NDMM admitted to the General Hospital of Tianjin Medical University General Hospital between 2017 and 2022. The least absolute shrinkage and selection operator (LASSO) regression was used to screen the predictive subgroups from the peripheral blood lymphocyte subsets, and the optimal cutoff value was calculated through receiver operating characteristic curve analysis. A nomogram was constructed based on the results of the multiple-factor analysis, and the predictive performance of the nomogram was evaluated by the concordance index and calibration curve. Kaplan-Meier curves and log-rank tests were conducted to compare the differences in overall survival (OS) and progression-free survival between the high-risk and low-risk immune risk scores groups.Results:Using LASSO regression, the percentages and absolute counts of CD16 +CD56 + NK cells, CD3 + T lymphocytes, CD3 +CD8 + T lymphocytes, and CD3 -CD19 + B lymphocytes were selected as predictive subgroups. The immune risk score of patients with NDMM was calculated based on the coefficients of each lymphocyte subgroup. The area under the curve of the immune risk score was 0.737, and the optimal cutoff value was -1.834. Based on this, the patients were divided into high-risk and low-risk groups. Survival analysis showed a significant difference in the 3-year OS rate between the high-risk and low-risk immune risk score groups (87.4% vs 49.0%, P<0.001), and a significant difference in the 3-year OS rate between the high-risk and low-risk immune risk score groups in patients with minimal residual disease negative (100% vs 68.6%, P=0.001). Multivariate analysis showed that serum calcium ( P=0.034), high-risk cytogenetic abnormalities ( P=0.002), and immune risk score ( P<0.001) were prognostic factors for patients with NDMM, and a nomogram was constructed based on these factors. The consistency index of the nomogram was 0.793, and the calibration curve showed good predictive ability. The nomogram can accurately classify the risk of different prognostic staging systems. Conclusions:The combined analysis of lymphocyte subsets in the peripheral blood has an important value in predicting the prognosis of patients with NDMM.

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.