Objective: Exploring the effect and mechanism of Xinyang Tablet on reduction of ferroptosis in myocardial cells from mice with chronic heart failure. Methods: Sixty C57BL/6J mice were randomly assigned to the sham, model, Xinyang Tablet low-dose (0.34 g/kg), Xinyang Tablet medium-dose (0.68 g/kg), Xinyang Tablet high-dose (1.36 g/kg), and perindopril (0.607 mg/kg) groups using a random number table method (10 mice in each group). Except for the sham group, all other groups underwent aortic arch constriction surgery to construct a chronic heart failure model. On the third day after completion of the modeling, each treatment group was administered the corresponding medication by gavage, while the sham and model groups were administered equal volumes of water by gavage once a day for eight consecutive weeks. After treatment, cardiac ultrasound was used to detect the structure and function of the mouse heart. Hematoxylin and eosin staining was used to detect pathological changes in mouse heart tissue. Masson staining was used to detect the proportion of fibrotic area of mouse heart tissue. Realtime fluorescence PCR was used to detect the mRNA expression of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), collagen 3α (Col3α), and myosin heavy chain 7 (MYH7) in mouse myocardial tissue. Transmission electron microscope was used to detect the ultrastructure of myocardial cell mitochondria. Reactive oxygen species (ROS) staining was used to detect the mean fluorescence intensity of ROS in myocardial tissue. Micro-determination was used to detect superoxide dismutase (SOD) activity in myocardial tissue. An immunofluorescence assay was used to detect the mean fluorescence intensity of phosphorylated histone deacetylase 2 (p-HDAC2) in myocardial cell. Western blotting was used to detect the protein expression of nuclear factor-erythroid 2-related factor 2 (Nrf2), p-HDAC2, nicotinamide adenine dinucleotide phosphate oxidase 1 (NOX1), glutathione peroxidase 4 (GPX4), and cystine glutamate reverse transporter (xCT) in mouse myocardial tissue. Results: Compared to the sham group, the model group showed a decrease in left ventricular ejection fraction (LVEF), left ventricular fraction shortening (LVFS), an increase in left ventricular end-systolic diameter(LVESD) and left ventricular end-diastolic diameter (LVEDD), an increase in the proportion of cardiac fibrosis area, an increase in relative expression levels of ANP, BNP, Col3α, and MYH7 mRNA, an increase in ROS mean fluorescence intensity, a decrease in SOD activity, an increase in mean fluorescence intensity of p-HDAC2, an increase in relative expression levels of p-HDAC2 and NOX1 proteins, and a decrease in relative expression levels of Nrf2, GPX4, and xCT proteins (P<0.05). Myocardial fibrosis lesions are obvious, with disordered mitochondrial arrangement, decreased volume and shrinkage, increased membrane density, and reduced mitochondrial cristae. Compared to the model group, the LVEF and LVFS of mice in each dose group of Xinyang Tablet and the perindopril group increased, LVESD and LVEDD decreased, the proportion of fibrotic area of heart tissue decreased, the relative expression levels of ANP, BNP, Col3α, MYH7 mRNA decreased, ROS mean fluorescence intensity decreased, SOD activity increased, mean fluorescence intensity of p-HDAC2 decreased, relative expression levels of p-HDAC2 and NOX1 proteins decreased, and relative expression levels of Nrf2 and xCT proteins increased (P<0.05). Myocardial fibrosis was reduced, the mitochondrial arrangement was more regular, the mitochondria enlarged, the membrane density was reduced, and mitochondrial cristae increased. Compared to the model group, the relative expression level of the GPX4 protein in myocardial tissue increased in the Xinyang Tablet medium-, high-dose, and the perindopril groups (P<0.05). Conclusion Xinyang Tablet can improve ferroptosis and ventricular remodeling in mice with chronic heart failure by regulating the HDAC2-mediated Nrf2 antioxidant pathway.

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.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical Gram-positive bacteria isolates from bloodstream infections in China in 2022.Methods:The clinical isolates of Gram-positive 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:A total of 3 163 strains of Gram-positive pathogens were collected from 51 member units，and the top five bacteria were Staphylococcus aureus（ n=1 147，36.3%），coagulase-negative Staphylococci（ n=928，29.3%）， Enterococcus faecalis（ n=369，11.7%）， Enterococcus faecium（ n=296，9.4%）and alpha-hemolyticus Streptococci（ n=192，6.1%）. The detection rates of methicillin-resistant Staphylococcus aureus（MRSA）and methicillin-resistant coagulase-negative Staphylococci（MRCNS）were 26.4%（303/1 147）and 66.7%（619/928），respectively. No glycopeptide and daptomycin-resistant Staphylococci were detected. The sensitivity rates of Staphylococcus aureus to cefpirome，rifampin，compound sulfamethoxazole，linezolid，minocycline and tigecycline were all >95.0%. Enterococcus faecium was more prevalent than Enterococcus faecalis. The resistance rates of Enterococcus faecium to vancomycin and teicoplanin were both 0.5%（2/369），and no vancomycin-resistant Enterococcus faecium was detected. The detection rate of MRSA in southern China was significantly lower than that in other regions（ χ2=14.578， P=0.002），while the detection rate of MRCNS in northern China was significantly higher than that in other regions（ χ2=15.195， P=0.002）. The detection rates of MRSA and MRCNS in provincial hospitals were higher than those in municipal hospitals（ χ2=13.519 and 12.136， P<0.001）. The detection rates of MRSA and MRCNS in economically more advanced regions（per capita GDP≥92 059 Yuan in 2022）were higher than those in economically less advanced regions（per capita GDP<92 059 Yuan）（ χ2=9.969 and 7.606， P=0.002和0.006）. Conclusions:Among the Gram-positive pathogens causing bloodstream infections in China， Staphylococci is the most common while the MRSA incidence decreases continuously with time；the detection rate of Enterococcus faecium exceeds that of Enterococcus faecalis. The overall prevalence of vancomycin-resistant Enterococci is still at a low level. The composition ratio of Gram-positive pathogens and resistant profiles varies slightly across regions of China，with the prevalence of MRSA and MRCNS being more pronounced in provincial hospitals and areas with a per capita GDP≥92 059 yuan.