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 investigate the molecular mechanism of lipid metabolism disorder in mouse spleen tissues due to high-altitude hypoxia.Methods Ten C57BL/6 male mice were randomly divided into normoxia group(maintained at an altitude of 400 m)and high-altitude hypoxia group(maintained at 4200 m)for 30 days(n=5).Lipidomics and metabolomics analyses of the spleen tissue of the mice were conducted using liquid chromatography-mass spectrometry(LC-MS)to identify the differential metabolites,which were further analyzed by KEGG enrichment and pathway analyses,and the differential genes were screened through transcriptome sequencing.Bioinformatics analysis was conducted to identify the upstream target genes of the differential metabolites in specific metabolic pathways.RT-qPCR and Western blotting were used to detect mRNA expressions of 11β-hydroxysteroid dehydrogenase 1(HSD11B1),steroid 5α reductase 1(SRD5A1),prostaglandin-endoperoxide synthase 1(PTGS1),hematopoietic prostaglandin D synthetase(HPGDS),xanthine dehydrogenase(XDH),purine nucleoside phosphorylase(PNP),hypoxanthine guanine-phosphoribosyltransferase(HPRT)and extracellular 5'-nucleotidase(NT5E)and protein expressions of HSD11B1,SRD5A1,XDH,PNP and HPRT in the mouse spleens.Results We identified a total of 41 differential lipid metabolites in the mouse spleens,and these metabolites and the differential genes were enriched in steroid hormone biosynthesis,arachidonic acid metabolism,and purine metabolism pathways.Compared to the mice kept in normoxic conditions,the mice exposed to high-altitude hypoxia showed significantly upregulated expressions of adrenosterone,androsterone,prostaglandin D2,prostaglandin J2,xanthine,xanthosine,and uric acid in the spleen with also changes in the expression levels of HSD11B1,SRD5A1,PTGS1,HPGDS,XDH,PNP,HPRT,and NT5E.Conclusion High-altitude hypoxia can result in lipid metabolism disorder in mouse spleen tissue by affecting steroid hormone biosynthesis,arachidonic acid metabolism,and purine metabolism pathways.

Background::Findings on the association of genetic factors and colorectal cancer (CRC) survival are limited and inconsistent, and revealing the mechanism underlying their prognostic roles is of great importance. This study aimed to explore the relationship between functional genetic variations and the prognosis of CRC and further reveal the possible mechanism.Methods::We first systematically performed expression quantitative trait locus (eQTL) analysis using The Cancer Genome Atlas (TCGA) dataset. Then, the Kaplan-Meier analysis was used to filter out the survival-related eQTL target genes of CRC patients in two public datasets (TCGA and GSE39582 dataset from the Gene Expression Omnibus database). The seven most potentially functional eQTL single nucleotide polymorphisms (SNPs) associated with six survival-related eQTL target genes were genotyped in 907 Chinese CRC patients with clinical prognosis data. The regulatory mechanism of the survival-related SNP was further confirmed by functional experiments.Results::The rs71630754 regulating the expression of endoplasmic reticulum aminopeptidase 1 ( ERAP1) was significantly associated with the prognosis of CRC (additive model, hazard ratio [HR]: 1.43, 95% confidence interval [CI]: 1.08-1.88, P = 0.012). The results of dual-luciferase reporter assay and electrophoretic mobility shift assay showed that the A allele of the rs71630754 could increase the binding of transcription factor 3 (TCF3) and subsequently reduce the expression of ERAP1. The results of bioinformatic analysis showed that lower expression of ERAP1 could affect the tumor immune microenvironment and was significantly associated with severe survival outcomes. Conclusion::The rs71630754 could influence the prognosis of CRC patients by regulating the expression of the immune-related gene ERAP1. Trial Registration::No. NCT00454519 (https://clinicaltrials.gov/)

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.

Objective To investigate the molecular mechanism of lipid metabolism disorder in mouse spleen tissues due to high-altitude hypoxia.Methods Ten C57BL/6 male mice were randomly divided into normoxia group(maintained at an altitude of 400 m)and high-altitude hypoxia group(maintained at 4200 m)for 30 days(n=5).Lipidomics and metabolomics analyses of the spleen tissue of the mice were conducted using liquid chromatography-mass spectrometry(LC-MS)to identify the differential metabolites,which were further analyzed by KEGG enrichment and pathway analyses,and the differential genes were screened through transcriptome sequencing.Bioinformatics analysis was conducted to identify the upstream target genes of the differential metabolites in specific metabolic pathways.RT-qPCR and Western blotting were used to detect mRNA expressions of 11β-hydroxysteroid dehydrogenase 1(HSD11B1),steroid 5α reductase 1(SRD5A1),prostaglandin-endoperoxide synthase 1(PTGS1),hematopoietic prostaglandin D synthetase(HPGDS),xanthine dehydrogenase(XDH),purine nucleoside phosphorylase(PNP),hypoxanthine guanine-phosphoribosyltransferase(HPRT)and extracellular 5'-nucleotidase(NT5E)and protein expressions of HSD11B1,SRD5A1,XDH,PNP and HPRT in the mouse spleens.Results We identified a total of 41 differential lipid metabolites in the mouse spleens,and these metabolites and the differential genes were enriched in steroid hormone biosynthesis,arachidonic acid metabolism,and purine metabolism pathways.Compared to the mice kept in normoxic conditions,the mice exposed to high-altitude hypoxia showed significantly upregulated expressions of adrenosterone,androsterone,prostaglandin D2,prostaglandin J2,xanthine,xanthosine,and uric acid in the spleen with also changes in the expression levels of HSD11B1,SRD5A1,PTGS1,HPGDS,XDH,PNP,HPRT,and NT5E.Conclusion High-altitude hypoxia can result in lipid metabolism disorder in mouse spleen tissue by affecting steroid hormone biosynthesis,arachidonic acid metabolism,and purine metabolism pathways.

Objective:To screen highly expressed inflammatory factors in diabetic nephropathy models using protein microarray, analyze differential genes and their regulatory networks, and predict potential therapeutic small molecular compounds.Methods:The inflammatory factor microarray was used to screen the inflammatory factors with the same tendency in the cell model and animal model of diabetic nephropathy. The differential genes screened by R language were enriched and analyzed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG). STRING builds a protein interaction network online, Cytoscape software analyzes the core subnetwork, and Connectivity Map searches for and predicts small molecule compounds.Results:Diabetic nephropathy model was established using 16-week-old db/db mice and mesangial cells stimulated with high glucose, and the expression of C-X-C motif chemokine ligand 1(CXCL1) was elevated in both models. Multiple GEO datasets indicated a strong association between the high expression of CXCL1 and diabetic nephropathy. Specifically, GSE30122 showed an upregulation of 30 genes and a downregulation of 23 genes. GO enrichment analysis focused on biological processes such as humoral immunity and lipopolysaccharide response; While KEGG enrichment was mainly in pertussis and coagulation cascade pathways. CytoHubba identified 10 hub genes, such as ALB, LUM, and CXCL1. In addition, 10 small molecule compounds were predicted as potential therapeutic drugs using Connectivity Map.Conclusions:CXCL1 may serve as a key gene in the occurrence and development of diabetic nephropathy. ALB, LUM, CXCL1, MMP7, TGFBI, CCL2, S100A4, SOX9, VCAN, and CLU may participate in the regulatory network centered around CXCL1. There are 10 small molecular compounds demenestrating the potential to be therapeutic agents.

Ulcerative colitis （UC） is a common chronic digestive system disease in clinic. The disease is repeated and difficult to treat， and the pathogenesis is complex， which is related to oxidative stress response. Nuclear factor E₂-related factor 2 （Nrf2） is an important factor in antioxidant reaction， which regulates the expression of downstream heme oxygen-1 （HO-1）， and plays a role in maintaining redox homeostasis. In the course of UC， the biological activity and content of Nrf2 and HO-1 are decreased， the antioxidant and anti-inflammatory abilities of tissues are weakened， the intestinal epithelial cells are damaged， and the intestinal mucosal barrier is destroyed. At present， western medicine mainly focuses on controlling inflammation and alleviating symptoms in clinical treatment. Although it has a certain effect， there are many problems such as easy recurrence after drug withdrawal and long-term side effects. Studies have shown that Chinese medicine has rich and flexible therapeutic methods and has broad application prospects in the prevention and treatment of UC. In recent years， with Nrf2/HO-1 pathway as the entry point， a large number of basic and clinical experiments on this signal in UC have been carried out in the field of Chinese medicine， and the results show that the intervention of Nrf2/HO-1 pathway is an important potential target for the treatment of UC by Chinese medicines. Based on the etiology and pathogenesis of deficiency-excess in complexity， Chinese medicine regulates Nrf2/HO-1 pathway by clearing heat and detoxifying dampness， activating blood circulation to remove stasis and relieve pain， invigorating Qi， tonifying middle， and warming interior， and treating both symptoms and root causes， to improve the tissue's ability to resist oxidative stress， maintain the balance between pro-inflammatory factors and anti-inflammatory factors， relieve inflammatory response， and play a therapeutic role in UC. This paper summarized and analyzed the effect of Chinese medicine targeting the Nrf2/HO-1 signaling pathway on interfering with UC and its mechanism. The purpose of this study is to provide references for researchers to have a more comprehensive understanding of the mechanism of Chinese medicines in the Nrf2/HO-1 signaling pathway in UC and promote the rational application of Chinese medicines in the prevention and treatment of UC in the future.

Objective:To report the results of national surveillance on the distribution and antimicrobial resistance profile of clinical bacterial isolates from bloodstream infections in China in 2021.Methods:The clinical bacterial strains isolated from blood culture from member hospitals of Blood Bacterial Resistant Investigation Collaborative System (BRICS) were collected during January 2021 to December 2021. Antibiotic susceptibility tests were conducted by agar dilution or broth dilution methods recommended by Clinical Laboratory Standards Institute (CLSI). WHONET 5.6 was used to analyze data.Results:During the study period, 11 013 bacterial strains were collected from 51 hospitals, of which 2 782 (25.3%) were Gram-positive bacteria and 8 231 (74.7%) were Gram-negative bacteria. The top 10 bacterial species were Escherichia coli (37.6%), Klebsiella pneumoniae (18.9%), Staphylococcus aureus (9.8%), coagulase-negative Staphylococci (6.3%), Pseudomonas aeruginosa (3.6%), Enterococcus faecium (3.6%), Acinetobacter baumannii (2.8%), Enterococcus faecalis (2.7%), Enterobacter cloacae (2.5%) and Klebsiella spp (2.1%). The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococcus aureus were 25.3% and 76.8%, respectively. No glycopeptide- and daptomycin-resistant Staphylococci was detected; more than 95.0% of Staphylococcus aureus were sensitive to ceftobiprole. No vancomycin-resistant Enterococci strains were detected. The rates of extended spectrum B-lactamase (ESBL)-producing isolated in Escherichia coli, Klebsiella pneumoniae and Proteus mirabilis were 49.6%, 25.5% and 39.0%, respectively. The prevalence rates of carbapenem-resistance in Escherichia coli and Klebsiella pneumoniae were 2.2% and 15.8%, respectively; 7.9% of carbapenem-resistant Klebsiella pneumoniae was resistant to ceftazidime/avibactam combination. Ceftobiprole demonstrated excellent activity against non-ESBL-producing Escherichia coli and Klebsiella pneumoniae. Aztreonam/avibactam was highly active against carbapenem-resistant Escherichia coli and Klebsiella pneumoniae. The prevalence rate of carbapenem-resistance in Acinetobacter baumannii was 60.0%, while polymyxin and tigecycline showed good activity against Acinetobacter baumannii (5.5% and 4.5%). The prevalence of carbapenem-resistance in Pseudomonas aeruginosa was 18.9%. Conclusions:The BRICS surveillance results in 2021 shows that the main pathogens of blood stream infection in China are gram-negative bacteria, in which Escherichia coli is the most common. The MRSA incidence shows a further decreasing trend in China and the overall prevalence of vancomycin-resistant Enterococci is low. The prevalence of Carbapenem-resistant Klebsiella pneumoniae is still on a high level, but the trend is downwards.

Objective : Based on metabolomics and transcriptomics analysis , to explore the molecular mechanism of spleen inflammation induced by high altitude hypoxia in mice through NOD⁃like receptor signaling pathway . Methods : C57BL/6 mice were raised at an altitude of 400 m and 4 200 m respectively , with five mice in each group , and spleen tissues were collected after 30 days . Differential metabolites and differentially expressed genes in key pathways were screened by metabolomics and transcriptome analysis and correlation KEGG enrichment analysis , and the related network interaction diagram of differential metabolites and differentially expressed genes in key pathways was constructed and verified by RT⁃qPCR . Results : Metabolomics analysis showed that 133 differential metabolites were screened from in the plain spleen control group (PSC group) and the plateau spleen test group (HST group) , 95 of which were up⁃regulated while 38 of which were down⁃regulated . KEGG enrichment analysis showed that they were mainly involved in NOD⁃like receptor signaling pathway , HIF⁃1 signaling pathway , cholesterol metabolism and other metabolic pathways . The results of transcriptome analysis showed that a total of 4213 differentially expressed genes were identified in PSC group and HST group , including 1947 up⁃regulated genes and 2266 down⁃regulated genes . KEGG was enriched in 173 signaling pathways , including NOD⁃like receptor signaling pathway , MAPK signaling pathway , NF⁃κB signaling pathway and other pathways . Comprehensive analysis showed that the differential metabolites and differentially expressed genes were obviously enriched in NOD⁃like receptor signaling pathway . Therefore , the correlation network interaction map was constructed for the differential metabolites ATP and differentially expressed genes in NOD⁃like receptor signaling pathway . RT⁃qPCR results showed that compared with PSC group , the expression levels of DEGs related to NOD1 and NOD2 (CHUK , TAB3 , MAPK8) in the signaling pathway of NOD⁃like receptor and NLRP1 ⁃CASP1 pathway (NLRP1b , CASP1) in HST group were significantly enhanced . The mRNA expression levels of downstream inflammatory factors IL⁃6 , IL⁃1 β , IL⁃18 , INF⁃γ and TNF⁃α were up⁃regulated and differentially expressed . Conclusion Based on the combined analysis of metabolomics and transcriptomics , it was found that hypoxia stimulation at high altitude may affect the NOD⁃like receptor signaling pathway in vivo , and the differential metabolite ATP is positively correlated with the differential key genes in the pathway . ATP mediates the release of downstream inflammatory factors by activating NOD1 , NOD2 pathways and NLRP1 inflammable⁃CASP1 pathways . Inflammatory response occurred in spleen tissue of mice.

Objective:To predict and evaluate the antibacterial efficacy of linezolid, teicoplanin and daptomycin against Staphylococci bloodstream infections with Monte Carlo simulation, and to optimize the clinical administration program. Methods:A total of 1 847 Staphylococci strains isolated from blood samples between January 2018 to December 2019 were collected with the help of the Blood Bacterial Resistant Investigation Collaborative System (BRICS). Minimum inhibitory concentrations (MIC) of linezolid and daptomycin were detected by broth dilution method, while MIC of teicoplanin were detected by agar dilution method. The dosage regimens of linezolid were 800 mg once daily, 500 mg once every 12 hours, 600 mg once every 12 hours and 600 mg once every eight hours. The dosage regimens of teicoplanin were 400 mg once every 12 hours, 600 mg once every 12 hours, 800 mg once every 12 hours, and 1 000 mg once every 12 hours. The dosage regimens of daptomycin were 4 mg·kg -1·d -1, 6 mg·kg -1·d -1, 8 mg·kg -1·d -1, 10 mg·kg -1·d -1and 12 mg·kg -1·d -1. The probability of target attainment (PTA) and cumulative fraction of response (CFR) of three different dosage regimens were calculated by Monte Carlo simulation. A dosage regimen with CFR≥90.0% was a reasonable choice for empirical antimicrobial therapy. Results:PTA of linezolid against Staphylococci when MIC≤0.500 mg/L at four dosage regimens (800 mg once daily, 500 mg once every 12 hours, 600 mg once every 12 hours and 600 mg once every eight hours) were all over 90.0%. When MIC was 1.000 mg/L, the PTA of linezolid against Staphylococci under the dosages of 500 mg once every 12 hours, 600 mg once every 12 hours and 600 mg once every eight hours were 92.2%, 96.6% and 97.6%, respectively. The CFR of the four dosage regimens of linezolid were 73.9%, 83.7%, 90.8% and 95.3%, respectively. When MIC≤1.000 mg/L, PTA of teicoplanin against Staphylococci were all 100.0% at four dosage regimens (400 mg once every 12 hours, 600 mg once every 12 hours, 800 mg once every 12 hours and 1 000 mg once every 12 hours). When MIC was 2.000 mg/L, the PTA of teicoplanin (800 mg once every 12 hours and 1 000 mg once every 12 hours) against Staphylococci were both 100.0%. The CFR of the four dosage regimens of teicoplanin were 90.8%, 92.8%, 93.5% and 94.6%, respectively. When MIC≤0.500 mg/L, PTA of daptomycin against Staphylococci under the five dosages of 4 mg·kg -1·d -1, 6 mg·kg -1·d -1, 8 mg·kg -1·d -1, 10 mg·kg -1·d -1 and 12 mg·kg -1·d -1 were all over 90.0%. When MIC was 1.000 mg/L, the PTA of daptomycin against Staphylococci under the three dosages of 8 mg·kg -1·d -1, 10 mg·kg -1·d -1 and 12 mg·kg -1·d -1were 96.9%, 100.0% and 100.0%, respectively. The CFR of the five dosage regimens of daptomycin against Staphylococci were 97.4%, 99.2%, 99.9%, 100.0% and 100.0%, respectively. Conclusions:Linezolid (600 mg once every 12 hours), teicoplanin (400 mg once every 12 hours) and daptomycin (4 mg·kg -1·d -1) can achieve satisfactory antibacterial activity for Staphylococci bloodstream infections.