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 explore the predictive value of the nomogram model based on multimodal MRI signs for adverse pregnancy outcomes in placenta accreta spectrum disorders(PAS).Methods The clinical and MRI data of 60 patients with PAS diagnosed by surgery and/or pathology were collected.Multivariate logistic regression was used to analyze the independent risk factors of adverse pregnancy outcomes in PAS.According to the results of multivariate logistic regression analysis,the nomogram prediction model of adverse pregnancy outcomes in PAS was constructed.Results Placenta/uterine protrusion[odds ratio(OR)=6.717,P=0.015],abnormal blood vessels in the placenta(OR=7.929,P=0.009),and diffusion weighted imaging(DWI)placental spike/nodular protrusion into the muscular layer(OR=12.134,P=0.003)were independent risk factors for adverse pregnancy outcomes in PAS.Based on the results,a nomogram prediction model was constructed.The area under the curve(AUC)of the model for predicting adverse pregnancy outcomes of PAS was 0.907,with a sensitivity of 0.906 and a specificity of 0.821.Conclusion The nomogram model constructed based on multimodal MRI signs has certain value in predicting adverse pregnancy outcomes of PAS.

Objective To explore the value of multi-parameter MRI in predicting the Ki-67 expression level in nasopharyngeal carcinoma(NPC).Methods The clinical and MRI data of 63 patients with pathologically confirmed NPC were prospectively collected.All patients underwent routine plain and enhanced nasopharyngeal MRI,diffusion weighted imaging(DWI),and arterial spin labeling(ASL)scans before treatment.Multivariate logistic regression analysis was used to identify the independent risk factors for the Ki-67 expression level.Results The degree of enhancement,the maximum blood flow(BFmax),and the minimum apparent diffusion coefficient(ADCmin)were independent risk factors for the Ki-67 expression level in NPC patients.The area under the curve(AUC)of the prediction model established based on these three factors was 0.920,with a sensitivity of 0.792 and a specificity of 0.897,respectively.Conclusion Multi-parameter MRI based on conventional enhancement,ASL,and DWI can effectively predict the Ki-67 expression level in NPC patients.

Objective To explore the predictive value of the nomogram model based on multimodal MRI signs for adverse pregnancy outcomes in placenta accreta spectrum disorders(PAS).Methods The clinical and MRI data of 60 patients with PAS diagnosed by surgery and/or pathology were collected.Multivariate logistic regression was used to analyze the independent risk factors of adverse pregnancy outcomes in PAS.According to the results of multivariate logistic regression analysis,the nomogram prediction model of adverse pregnancy outcomes in PAS was constructed.Results Placenta/uterine protrusion[odds ratio(OR)=6.717,P=0.015],abnormal blood vessels in the placenta(OR=7.929,P=0.009),and diffusion weighted imaging(DWI)placental spike/nodular protrusion into the muscular layer(OR=12.134,P=0.003)were independent risk factors for adverse pregnancy outcomes in PAS.Based on the results,a nomogram prediction model was constructed.The area under the curve(AUC)of the model for predicting adverse pregnancy outcomes of PAS was 0.907,with a sensitivity of 0.906 and a specificity of 0.821.Conclusion The nomogram model constructed based on multimodal MRI signs has certain value in predicting adverse pregnancy outcomes of PAS.

Objective To explore the value of multi-parameter MRI in predicting the Ki-67 expression level in nasopharyngeal carcinoma(NPC).Methods The clinical and MRI data of 63 patients with pathologically confirmed NPC were prospectively collected.All patients underwent routine plain and enhanced nasopharyngeal MRI,diffusion weighted imaging(DWI),and arterial spin labeling(ASL)scans before treatment.Multivariate logistic regression analysis was used to identify the independent risk factors for the Ki-67 expression level.Results The degree of enhancement,the maximum blood flow(BFmax),and the minimum apparent diffusion coefficient(ADCmin)were independent risk factors for the Ki-67 expression level in NPC patients.The area under the curve(AUC)of the prediction model established based on these three factors was 0.920,with a sensitivity of 0.792 and a specificity of 0.897,respectively.Conclusion Multi-parameter MRI based on conventional enhancement,ASL,and DWI can effectively predict the Ki-67 expression level in NPC patients.

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.

BACKGROUND:Icariin,with antiinflammatory,antioxygenatory and immunoregulatory effects,can be a potential drug for preventing and treating acute liver injury. OBJECTIVE:To investigate the protective effect and possible mechanism of icariin in mice with acute liver injury induced by carbon tetrachloride. METHODS:Thirty-two Kunming mice were equally and randomly divided into the following groups:normal,model,low-dose icariin and high-dose icariin groups.The low-and high-dose icariin groups were continuously gavaged with icariin(100 and 200 mg/kg,respectively)once a day for 7 continuous days.The normal group and model group were injected with physiological saline(10 mL/kg)at the same time point.After the last administration,all the groups except for the normal group were injected with carbon tetrachloride to induce acute liver injury.The mice were killed 24 hours later,and the liver index was detected.Serum levels of alanine aminotransferase and aspartate aminotransferase were detected by automated biochemical analysis.Tumor necrosis factor α and interleukin 6 levels in serum were detected using ELISA.The levels of superoxide dismutase,glutathione peroxidase and malondialdehyde in liver tissue were detected through a reagent kit.The histopathology changes of the liver were observed by hematoxylin-eosin staining.TUNEL method was used to detect the apoptosis in hepatocytes.Western blot was performed to detect the expression levels of glucose-regulated protein 78 kDa,endoplasmic reticulum stress-related protein(C/-EBP homologous protein),mixed lineage kinase domain-like protein and Caspase-3 in liver tissue. RESULTS AND CONCLUSION:Compared with the normal group,the liver index and serum levels of alanine aminotransferase,aspartate aminotransferase,tumor necrosis factor α and interleukin 6 were increased in the model group(P＜0.05).Compared with the model group,the above indexes were decreased in the low-dose and high-dose icariin groups(P＜0.05).Compared with the normal group,the activities of superoxide dismutase and glutathione peroxidase in the liver tissue of mice were decreased in the model group(P＜0.05)and the level of malondialdehyde was increased(P＜0.05).Compared with the model group,the activities of superoxide dismutase and glutathione peroxidase were increased in the low-and high-dose icariin groups(P＜0.05)and the level of malondialdehyde was decreased(P＜0.05).Hematoxylin-eosin and TUNEL staining showed that mice in the model group had severe structural destruction of liver tissue,extensive necrosis of hepatocytes and high apoptotic rate of hepatocytes,while the structural destruction of liver tissue and the area of necrosis of hepatocytes in the low-and high-dose icariin groups were significantly milder than those in the model group,and the apoptotic rate of hepatocytes was lower than that in the model group(P＜0.05).Western blot assay showed that the protein expression of glucose-regulated protein 78 kDa,C/-EBP homologous protein,mixed lineage kinase domain-like protein and Caspase-3 in liver tissue of mice in the model group was increased compared with that in the normal group(P＜0.05),while the expression levels of these proteins in liver tissue of mice were significantly reduced after low-and high-dose icariin intervention(P＜0.05).To conclude,icariin can produce a protective effect against carbon tetrachloride-induced acute liver injury,and its mechanism may be related to the regulation of endoplasmic reticulum stress and reduction of programmed necrosis.

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.