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 impact of imaging anatomical features on the prognosis of middle-aged and elderly patients with anomalous coronary artery originating from the opposite sinus (ACAOS).Methods:This retrospective cohort study enrolled patients aged ≥45 years who were diagnosed with ACAOS by coronary computed tomography angiography (CTA) at the Affiliated Hospital of Xuzhou Medical University between January 1, 2011, and December 31, 2018. Baseline clinical data and coronary CTA images were collected. Anatomic imaging features were extracted, including ACAOS subtype, course of the anomalous vessel, and ostial angle. The primary endpoint was major adverse cardiovascular events (MACE), defined as a composite of acute myocardial infarction, cardiac death, and coronary revascularization. The Maxstat method was used to determine the cut-off values of specific anatomical features for predicting MACE risk. Cox proportional hazards models were employed to analyze the impact of these imaging features on MACE in middle-aged and elderly ACAOS patients.Results:A total of 203 patients were enrolled, aged (60.0(51.0, 66.0)) years, including 119 (58.6%) males. Over a follow-up of (98.2±30.9) months, 39 patients experienced MACE. Maxstat identified an optimal cut-off value of 34.3° for the ostial angle of the anomalous vessel. Multivariable Cox proportional hazards regression analysis revealed that the following factors were independent risk factors for MACE: left-sided ACAOS subtype ( HR=4.35, 95% CI 2.17-8.73, P<0.001), an interarterial course between the aorta and pulmonary artery ( HR=3.21, 95% CI 1.23-8.37, P=0.017), an anomalous vessel ostial angle <34.3° ( HR=2.62, 95% CI 1.18-5.77, P=0.017), and concomitant coronary artery disease ( HR=2.92, 95% CI 1.49-5.73, P=0.002). Conclusion:In middle-aged and elderly patients with ACAOS, the imaging anatomical features of a left-sided ACAOS subtype, an interarterial course, and an ostial angle <34.3° are independent risk factors for MACE.

Objectives:We evaluated the clinical significance of unipolar electrogram and bipolar electrogram in guiding radiofrequency ablation for outflow tract ventricular premature contractions(PVC).Methods:Data were collected from 78 patients who underwent successful radiofrequency ablation of PVC.Pre-procedure electrocardiogram showed a LBBB morphology on inferior leads.In the included patients,the right-side ablation was performed at first,and if the ablation failed,the left-side ablation was then performed.According to the location of the successful ablation target,they were divided into unilateral ablation successful group and bilateral ablation successful group.The differences in the earliest bipolar local activation to QRS(LATBi),unipolar-dV/dTmax to QRS(LATUni),and local activation time were compared between the two groups.Furthermore,the electrogram characteristics predicting bilateral ablation were explored.Results:Patients were divided into unilateral ablation group(n=57)and bilateral ablation group(n=21)according to the ablation site.There were statistically significant differences in LATBi(25[21,30]ms vs.14[10,24]ms),LATUni(7[0,17]ms vs.-23[-41,-11]ms),and ΔLATBi-Uni(15[11,25]ms vs.44[25,56]ms)between the unilateral ablation group and the bilateral ablation group(all P<0.05).Multivariate regression analysis suggested that LATBi,LATUni,and ΔLATBi-Uni were independent predictors of the need for bilateral ablation.There was no significant difference between left and right LATBi,LATUni and ΔLATBi-Uni in the bilateral ablation group.LATUni≤-1 was the most accurate parameter for predicting the need for bilateral ablation(AUC=0.941;specificity 80.7%;sensitivity 100%).Conclusions:LATUni≤-1ms is a useful indicator for predicting the need for bilateral PVC ablation in this patient cohort.

Objective:To explore molecular mechanism of high-altitude hypoxia regulates PPAR signaling pathway induced ferroptosis in spleen.Methods:Hypoxia animal model was constructed,target genes were screened and predicted by combination of transcriptomics and protein omics.Key genes in PPAR and ferroptosis pathways under hypoxia exposure were explored by GO and KEGG enrichment analysis and verified by RT-qPCR and Western blot.Results:Combination of transcriptomics and protein omics showed that 95 predicted target genes(protein)showed significantly differential expression under hypoxic exposure.GO annotation analysis and KEGG enrichment analysis showed that differential genes were mainly significantly enriched in PPAR and ferroptosis signaling pathways.A negative correlation was found between PPAR and ferroptosis signaling pathways,and GSEA showed that differential gene sets of PPAR and ferroptosis signaling pathways exhibited opposite expression trend in high-altitude hypoxia group.Validation of key genes PPARA,RXRB,APOA1 and SCD-1 in PPAR signaling pathway revealed that both mRNA and protein expres-sions were down-regulated under hypoxic exposure.Subsequently,differential expression was observed in mRNA and protein expres-sions of GPX4 in endogenous pathway and SLC7A11,TRP53 and TFRC in exogenous pathway in ferroptosis signaling pathway.Corre-lations between four key genes for ferroptosis and differential inflammation-associated genes(DE-IRGs)were positively or negatively.IL-1β,IL-6,IL-12,IL-18,IFN-γ and TNF-α expressions in spleen tissue were up-regulated under hypoxic exposure.Conclusion:High-altitude hypoxia exposure further induces ferroptosis through PPAR signaling pathway-mediated lipid metabolism disorders,and accompanied by occurrence of inflammatory response,which causes damage of spleen tissue.

Objectives:We evaluated the clinical significance of unipolar electrogram and bipolar electrogram in guiding radiofrequency ablation for outflow tract ventricular premature contractions(PVC).Methods:Data were collected from 78 patients who underwent successful radiofrequency ablation of PVC.Pre-procedure electrocardiogram showed a LBBB morphology on inferior leads.In the included patients,the right-side ablation was performed at first,and if the ablation failed,the left-side ablation was then performed.According to the location of the successful ablation target,they were divided into unilateral ablation successful group and bilateral ablation successful group.The differences in the earliest bipolar local activation to QRS(LATBi),unipolar-dV/dTmax to QRS(LATUni),and local activation time were compared between the two groups.Furthermore,the electrogram characteristics predicting bilateral ablation were explored.Results:Patients were divided into unilateral ablation group(n=57)and bilateral ablation group(n=21)according to the ablation site.There were statistically significant differences in LATBi(25[21,30]ms vs.14[10,24]ms),LATUni(7[0,17]ms vs.-23[-41,-11]ms),and ΔLATBi-Uni(15[11,25]ms vs.44[25,56]ms)between the unilateral ablation group and the bilateral ablation group(all P<0.05).Multivariate regression analysis suggested that LATBi,LATUni,and ΔLATBi-Uni were independent predictors of the need for bilateral ablation.There was no significant difference between left and right LATBi,LATUni and ΔLATBi-Uni in the bilateral ablation group.LATUni≤-1 was the most accurate parameter for predicting the need for bilateral ablation(AUC=0.941;specificity 80.7%;sensitivity 100%).Conclusions:LATUni≤-1ms is a useful indicator for predicting the need for bilateral PVC ablation in this patient cohort.

Objective:To explore molecular mechanism of high-altitude hypoxia regulates PPAR signaling pathway induced ferroptosis in spleen.Methods:Hypoxia animal model was constructed,target genes were screened and predicted by combination of transcriptomics and protein omics.Key genes in PPAR and ferroptosis pathways under hypoxia exposure were explored by GO and KEGG enrichment analysis and verified by RT-qPCR and Western blot.Results:Combination of transcriptomics and protein omics showed that 95 predicted target genes(protein)showed significantly differential expression under hypoxic exposure.GO annotation analysis and KEGG enrichment analysis showed that differential genes were mainly significantly enriched in PPAR and ferroptosis signaling pathways.A negative correlation was found between PPAR and ferroptosis signaling pathways,and GSEA showed that differential gene sets of PPAR and ferroptosis signaling pathways exhibited opposite expression trend in high-altitude hypoxia group.Validation of key genes PPARA,RXRB,APOA1 and SCD-1 in PPAR signaling pathway revealed that both mRNA and protein expres-sions were down-regulated under hypoxic exposure.Subsequently,differential expression was observed in mRNA and protein expres-sions of GPX4 in endogenous pathway and SLC7A11,TRP53 and TFRC in exogenous pathway in ferroptosis signaling pathway.Corre-lations between four key genes for ferroptosis and differential inflammation-associated genes(DE-IRGs)were positively or negatively.IL-1β,IL-6,IL-12,IL-18,IFN-γ and TNF-α expressions in spleen tissue were up-regulated under hypoxic exposure.Conclusion:High-altitude hypoxia exposure further induces ferroptosis through PPAR signaling pathway-mediated lipid metabolism disorders,and accompanied by occurrence of inflammatory response,which causes damage of spleen tissue.

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 impact of imaging anatomical features on the prognosis of middle-aged and elderly patients with anomalous coronary artery originating from the opposite sinus (ACAOS).Methods:This retrospective cohort study enrolled patients aged ≥45 years who were diagnosed with ACAOS by coronary computed tomography angiography (CTA) at the Affiliated Hospital of Xuzhou Medical University between January 1, 2011, and December 31, 2018. Baseline clinical data and coronary CTA images were collected. Anatomic imaging features were extracted, including ACAOS subtype, course of the anomalous vessel, and ostial angle. The primary endpoint was major adverse cardiovascular events (MACE), defined as a composite of acute myocardial infarction, cardiac death, and coronary revascularization. The Maxstat method was used to determine the cut-off values of specific anatomical features for predicting MACE risk. Cox proportional hazards models were employed to analyze the impact of these imaging features on MACE in middle-aged and elderly ACAOS patients.Results:A total of 203 patients were enrolled, aged (60.0(51.0, 66.0)) years, including 119 (58.6%) males. Over a follow-up of (98.2±30.9) months, 39 patients experienced MACE. Maxstat identified an optimal cut-off value of 34.3° for the ostial angle of the anomalous vessel. Multivariable Cox proportional hazards regression analysis revealed that the following factors were independent risk factors for MACE: left-sided ACAOS subtype ( HR=4.35, 95% CI 2.17-8.73, P<0.001), an interarterial course between the aorta and pulmonary artery ( HR=3.21, 95% CI 1.23-8.37, P=0.017), an anomalous vessel ostial angle <34.3° ( HR=2.62, 95% CI 1.18-5.77, P=0.017), and concomitant coronary artery disease ( HR=2.92, 95% CI 1.49-5.73, P=0.002). Conclusion:In middle-aged and elderly patients with ACAOS, the imaging anatomical features of a left-sided ACAOS subtype, an interarterial course, and an ostial angle <34.3° are independent risk factors for MACE.