ObjectiveTo investigate the mechanism by which Feixin decoction treats hypoxic pulmonary hypertension （HPH） by regulating the peroxisome proliferator-activated receptor gamma （PPARγ）/nuclear factor-kappa B （NF-κB）/NOD-like receptor pyrin domain containing 3 （NLRP3） signaling pathway. MethodsForty-eight male SD rats were randomly allocated into normal， hypoxia， and low-， medium- and high-dose （5.85， 11.7， 23.4 g·kg^-1， respectively） Feixin decoction groups， with 8 rats in each group. Except the normal group， the remaining five groups were placed in a hypoxia chamber with an oxygen concentration of （10.0±0.5）% for 8 h per day， 28 days， and administrated with corresponding drugs during the modeling process. After 4 weeks of treatment， echocardiographic parameters ［pulmonary artery acceleration time （PAT）， pulmonary artery ejection time （PET）， right ventricular anterior wall thickness （RVAWd）， and tricuspid annular plane systolic excursion （TAPSE）］ were measured for each group. The right ventricular systolic pressure （RVSP） was measured by the right heart catheterization method， and the right ventricular hypertrophy index （RVHI） was calculated by weighing the heart. The pathological changes in pulmonary arterioles were observed by hematoxylin-eosin staining. The co-localization of α-smooth muscle actin （α-SMA） with NLRP3， N-terminal gasdermin D （N-GSDMD）， and cysteinyl aspartate-specific proteinase-1 （Caspase-1） in pulmonary arteries was detected by immunofluorescence. The protein levels of PPARγ， NF-κB， NLRP3， apoptosis-associated speck-like protein containing a CARD （ASC）， N-GSDMD， interleukin-1β （IL-1β）， interleukin-18（IL-18）， and cleaved Caspase-1 in the lung tissue was determined by Western blot. The ultrastructural changes in pulmonary artery smooth muscle cells （PASMCs） were observed by transmission electron microscopy. ResultsCompared with the normal group， the hypoxia group showed increased RVSP and RVHI （P<0.01）， decreased right heart function （P<0.01）， increased pulmonary vascular remodeling （P<0.01）， increased co-localization of α-SMA with NLRP3， N-GSDMD， and Caspase-1 in pulmonary arterioles （P<0.01）， up-regulated protein levels of NF-κB， NLRP3， ASC， N-GSDMD， IL-1β， IL-18， and cleaved Caspase-1 in the lung tissue （P<0.05， P<0.01）， a down-regulated protein level of PPARγ （P<0.05， P<0.01）， and pyroptosis in PASMCs. Compared with the hypoxia group， Feixin decoction reduced RVSP and RVHI， improved the right heart function and ameliorated pulmonary vascular remodeling （P<0.05， P<0.01）， decreased the co-localization of α-SMA with NLRP3， N-GSDMD， and Caspase-1 （P<0.05， P<0.01）， down-regulated the protein levels of NF-κB， NLRP3， ASC， N-GSDMD， IL-1β， IL-18， and cleaved Caspase-1 in the lung tissue （P<0.05， P<0.01）， up-regulated the protein level of PPARγ （P<0.05， P<0.01）， and alleviated pyroptosis in PASMCs. ConclusionFeixin decoction can ameliorate pulmonary vascular remodeling and right heart dysfunction in chronically induced HPH rats by regulating pyroptosis in PASMCs through the PPARγ/NF-κB/NLRP3 pathway.

ObjectiveTransfer RNA-derived fragments (tRFs) are a recently characterized and rapidly expanding class of small non-coding RNAs, typically ranging from 13 to 50 nucleotides in length. They are derived from mature or precursor tRNA molecules through specific cleavage events and have been implicated in a wide range of cellular processes. Increasing evidence indicates that tRFs play important regulatory roles in gene expression, primarily by interacting with target messenger RNAs (mRNAs) to induce transcript degradation, in a manner partially analogous to microRNAs (miRNAs). However, despite their emerging biological relevance and potential roles in disease mechanisms, there remains a significant lack of computational tools capable of systematically predicting the interaction landscape between tRFs and their target mRNAs. Existing databases often rely on limited interaction features and lack the flexibility to accommodate novel or user-defined tRF sequences. The primary goal of this study was to develop a machine learning based prediction algorithm that enables high-throughput, accurate identification of tRF:mRNA binding events, thereby facilitating the functional analysis of tRF regulatory networks. MethodsWe began by assembling a manually curated dataset of 38 687 experimentally verified tRF:mRNA interaction pairs and extracting seven biologically informed features for each pair: (1) AU content of the binding site, (2) site pairing status, (3) binding region location, (4) number of binding sites per mRNA, (5) length of the longest consecutive complementary stretch, (6) total binding region length, and (7) seed sequence complementarity. Using this dataset and feature set, we trained 4 distinct machine learning classifiers—logistic regression, random forest, decision tree, and a multilayer perceptron (MLP)—to compare their ability to discriminate true interactions from non-interactions. Each model’s performance was evaluated using overall accuracy, receiver operating characteristic (ROC) curves, and the corresponding area under the ROC curve (AUC). The MLP consistently achieved the highest AUC among the four, and was therefore selected as the backbone of our prediction framework, which we named tRF Prospect. For biological validation, we retrieved 3 high-throughput RNA-seq datasets from the gene expression omnibus (GEO) in which individual tRFs were overexpressed: AS-tDR-007333 (GSE184690), tRF-3004b (GSE197091), and tRF-20-S998LO9D (GSE208381). Differential expression analysis of each dataset identified genes downregulated upon tRF overexpression, which we designated as putative targets. We then compared the predictions generated by tRF Prospect against those from three established tools—tRFTar, tRForest, and tRFTarget—by quantifying the number of predicted targets for each tRF and assessing concordance with the experimentally derived gene sets. ResultsThe proposed algorithm achieved high predictive accuracy, with an AUC of 0.934. Functional validation was conducted using transcriptome-wide RNA-seq datasets from cells overexpressing specific tRFs, confirming the model’s ability to accurately predict biologically relevant downregulation of mRNA targets. When benchmarked against established tools such as tRFTar, tRForest, and tRFTarget, tRF Prospect consistently demonstrated superior performance, both in terms of predictive precision and sensitivity, as well as in identifying a higher number of true-positive interactions. Moreover, unlike static databases that are limited to precomputed results, tRF Prospect supports real-time prediction for any user-defined tRF sequence, enhancing its applicability in exploratory and hypothesis-driven research. ConclusionThis study introduces tRF Prospect as a powerful and flexible computational tool for investigating tRF:mRNA interactions. By leveraging the predictive strength of deep learning and incorporating a broad spectrum of interaction-relevant features, it addresses key limitations of existing platforms. Specifically, tRF Prospect: (1) expands the range of detectable tRF and target types; (2) improves prediction accuracy through multilayer perceptron model; and (3) allows for dynamic, user-driven analysis beyond database constraints. Although the current version emphasizes miRNA-like repression mechanisms and faces challenges in accurately capturing 5'UTR-associated binding events, it nonetheless provides a critical foundation for future studies aiming to unravel the complex roles of tRFs in gene regulation, cellular function, and disease pathogenesis.

Objective To explore the effect and mechanism of hydroxysafflor yellow A(HSYA)on autophagy in bEnd.3 cells after oxygen-glucose deprivation(OGD).Methods The bEnd.3 cells were divided into normal group(conventional culture),model group(OGD model),HSYA group(OGD model+75 μmol·L-1 HSYA),3-methyladenine(3MA)group(5 mmol·L-1 3MA+OGD model)and 3 MA+HSYA group(5 mmol·L-1 3 MA+OGD model+75 μmol·L-1 HSYA).The level of apoptosis was determined by TUNEL fluorescence staining;Western blot was used to detect the expression of autophagy,blood brain barrier(BBB)related proteins;real time fluorescence quantitative polymerase chain reaction method for determining the expression of sirtuin-1(SIRT1)and forkhead box protein O3a(FOXO3A)mRNA.Results In the normal group,model group,HSYA group,3MA group and 3MA+HSYA group,the positive cells selected for TUNEL staining were 5.00±1.00,28.00±2.00,21.00±3.00,35.33±2.51 and 29.67±2.52;the expression levels of microtubule-associated protein 1 light chain 3-Ⅱ/-Ⅰ(LC3-Ⅱ/-Ⅰ)were 0.90±0.20,1.34±0.10,1.95±0.14,0.76±0.15 and 1.14±0.09;sequestosome 1(P62)were 0.99±0.02,0.60±0.02,0.38±0.01,0.67±0.04 and 0.54±0.01;occludin were 1.39±0.17,0.62±0.15,1.00±0.09,0.40±0.13 and 0.80±0.15;zonula occludens-1(ZO-1)were 1.63±0.20,0.64±0.06,0.98±0.14,0.37±0.14 and 0.87±0.04;SIRT1 mRNA were 1.00±0.00,0.75±0.07,1.69±0.09,0.31±0.02 and 0.56±0.01;FOXO3A mRNA were 1.00±0.00,0.80±0.05,1.47±0.09,0.40±0.01 and 0.62±0.09,respectively.Significant differences were found between model group and normal group,HSYA group and model group,3MA+HSYA group and 3MA group(P＜0.05,P＜0.01,P＜0.001).Conclusion HSYA may enhance autophagy levels in bEnd.3 cells after OGD through the SIRT1/FOXO3A pathway,inhibit cell apoptosis and alleviate BBB damage.

Tumor immune microenvironment is a local external tumor environment composed of tumor immune cells and the cytokines secreted by these cells， and it plays a regulatory role in the development and progression of tumors. In the treatment of hepatocellular carcinoma， amino acid metabolism and its reprogramming of proliferating cell metabolism have attracted more and more attention， showing potential in regulating the tumor immune microenvironment. Although amino acid metabolic reprogramming is regarded as a novel approach for tumor therapy， its specific mechanism remains unclear in the regulation of tumor immunity in hepatocellular carcinoma. This article discusses the mechanism of action of amino acid metabolism in the tumor immune microenvironment of hepatocellular carcinoma and its application prospect in clinical practice， in order to provide new ideas for immunotherapy for liver cancer.

Objective To investigate the clinical effect of rapamycin-eluting vertebral artery stent in the treatment of severe ostial vertebral artery stenosis(OV AS),and to analyze the incidence of postoperative in-stent restenosis(ISR).Methods A total of 96 patients with severe OVAS,who received stenting angioplasty at authors'hospital between November 2020 and May 2022,were retrospectively collected.The patients were divided into the observation group(n=48)and the control group(n=48).For the patients of the observation group implantation of rapamycin-eluting vertebral artery stent was carried out,while for the patients of the control group implantation of peripheral balloon dilatation bare metal stent(BMS)was performed.The perioperative basic data,the incidence of complications during follow-up period,and the postoperative incidence of ISR were compared between the two groups.Results Successful stent implantation was achieved in all patients of both groups.During perioperative period no complications such as transient ischemia attack(TIA),dropping-off or fracture of the stent,vertebral artery or stent-related stroke occurred.No statistically significant differences in the length and the diameter of the implanted stents,in the preoperative vertebral artery stenosis ratio,and in the postoperative residual stenosis ratio existed between the two groups(all P＞0.05).In both groups,the postoperative residual stenosis ratio was＜20％.The patients were followed up for a mean period of(12.33±5.82)months(range of 6-18 months),the incidence of postoperative vertebral artery or stent-related stroke in the observation group and the control group was 0％and 4.17％respectively,the difference between the two groups was not statistically significant(P＞0.05).The improvement of clinical symptoms such as dizziness,vertigo,etc.was observed in 47 patients of the observation group and in 45 patients of the control group,and no recurrent posterior circulation TIA or stent-related thrombotic event occurred.The incidence of postoperative restenosis in the observation group was 10.42％,which was significantly lower than 29.17％in the control group(P＜0.05).Conclusion Rapamycin-eluting vertebral artery stent can safely and effectively treat severe OVAS and reduce the incidence of postoperative ISR.(J Intervent Radiol,2024,33:275-279)

Objective To investigate the effect and mechanism of Feixin Decoction(Astragali Radix,Pericae Semen,Carthami Flos,Descurainiae Semen Lepidii Semen,Paeoniae Radix Rubra,etc.)on monocrotaline-induced pulmonary arterial hypertension(PAH)rats based on peroxisome proliferator-activated receptor-γ/nuclear factor-κB(PPAR-γ/NF-κB)signaling pathway.Methods Forty-eight male SD rats were randomly divided into normal group,model group,Sildenafil group(0.025 g·kg-1)and low-,medium-and high-dose of Feixin Decoction groups(11.7,23.4,46.8 g·kg-1).PAH rat model was established by single intraperitoneal injection of monocrotaline solution(60 mg·kg-1).After 1 hour of modeling,the rats were given intragastric administration once a day for 28 days.Hemodynamic and echocardiographic parameters including right ventricular systolic pressure(RVSP),mean pulmonary artery pressure(mPAP),right ventricular hypertrophy index(RVHI),pulmonary artery acceleration time(PAAT),pulmonary artery ejection time(PET),tricuspid annular plane systolic excursion(TAPSE),right ventricular internal diameter(RVIDd)and right ventricular anterior wall thickness(RVAWT)were measured in each group.The pathological changes of pulmonary arterioles were observed by HE staining.The expression level of α-smooth muscle actin(α-SMA)in rat pulmonary artery was detected by immunofluorescence.The levels of plasma interleukin-1β(IL-1β),IL-6 and tumor necrosis factor-α(TNF-α)were detected by ELISA.The expression levels of PPAR-γ/NF-κB signaling pathway-related proteins were detected by immunohistochemistry and Western Blot.Results Compared with the normal group,the RVSP,mPAP,RVHI,RVIDd and RVAWT of the model group were significantly increased(P＜0.01).PAAT,PAAT/PET and TAPSE were significantly decreased(P＜0.01).The wall of pulmonary arterioles was significantly thickened,and the percentage of wall thickness of pulmonary arterioles to vascular diameter and the percentage of vascular wall area to total cross-sectional area of pulmonary arterioles were significantly increased(P＜0.01).The positive expression rate of α-SMA protein in pulmonary artery was significantly increased(P＜0.01).The levels of plasma IL-1β,IL-6 and TNF-α were significantly increased(P＜0.01).The positive expression rate of PPAR-γ protein in lung tissue was significantly decreased(P＜0.01),and the positive expression rate of NF-κB protein was significantly increased(P＜0.01).The protein expressions of PPAR-γ and IκB-α in lung tissue were significantly down-regulated(P＜0.01).The protein expression ratio of p-NF-κB/NF-κB was significantly increased(P＜0.01).Compared with the model group,RVSP,mPAP,RVHI,RVIDd and RVAWT in each administration group were significantly decreased(P＜0.05,P＜0.01),while PAAT,PAAT/PET and TAPSE were significantly increased(P＜0.05,P＜0.01).The thickness of the vascular wall was significantly reduced,and the percentage of the wall thickness of the pulmonary arterioles to the diameter of the blood vessels and the percentage of the vascular wall area to the total cross-sectional area of the small arteries were significantly reduced(P＜0.05,P＜0.01).The positive expression rate of α-SMA protein in pulmonary artery was significantly decreased(P＜0.05,P＜0.01).The plasma levels of IL-1β,IL-6 and TNF-α were significantly decreased(P＜0.05,P＜0.01).The positive expression rate of PPAR-γ protein in lung tissue was significantly increased(P＜0.05,P＜0.01),and the positive expression rate of NF-κB protein was significantly decreased(P＜0.05,P＜0.01).The protein expression of PPAR-γ in lung tissue was significantly up-regulated(P＜0.05,P＜0.01),and the protein expression ratio of p-NF-κB/NF-κB was significantly decreased(P＜0.01).The protein expression of IκB-α in the lung tissue of rats in the high-dose group of Feixin Decoction was significantly up-regulated(P＜0.01).Conclusion Feixin Decoction can improve pulmonary artery pressure,right ventricular dysfunction and pulmonary vascular remodeling in PAH rats induced by monocrotaline.The mechanism may be related to the regulation of PPAR-γ/NF-κB signaling pathway to inhibit inflammatory response.

Objective To investigate the treatment of female bladder neck obstruction by 1470nm laser transurethral modified enlarged female bladder neck obstruction(FBNO).Methods The clinical data of 34 patients with FBNO from January 2019 to November 2021 were retrospectively analyzed.The patient underwent a 1470nm laser transurethral modified enlarged bladder neck incision.The 1470nm laser was used to vaporise the bladder neck at 12 o'clock(lithotomy),and the incision site was expanded along the bladder neck to 9 o'clock and 3 o'clock to form a semi-circular surgical wound.The patients were followed up for complications,scored form of Bristol female lower urinary tract symptoms questionnaire(BFLUTS-SF)urination symptom subscale,quality of life(QoL)score and the maximum urinary flow rate(Qmax),detrusor pressure at maximum flow rate(PdetQmax),post-void residual(PVR)were reviewed at 1,4,and 10 months after operation.Results After 10 months of follow-up,the subjective indexes of BFLUTS-SF and QoL scores were significantly improved compared with those before operation(P<0.001),and the objective indexes of Qmax,PdetQmax,and PVR were significantly improved compared with those before operation(P<0.001).Two patients had mild urgency urinary incontinence and urinary tract infection symptoms half a month after operation,and the symptoms were improved after anti-infection and pelvic floor rehabilitation treatment.During the follow-up period,there were no complications such as vesicovaginal fistula,stress urinary incontinence,or recurrent bladder neck obstruction.Conclusion 1470nm laser transurethral modified enlarged bladder neck resection can effectively relieve bladder neck obstruction without significant postoperative complications,with high safety and good patient satisfaction.

Bacterial biofilms gave rise to persistent infections and multi-organ failure, thereby posing a serious threat to human health. Biofilms were formed by cross-linking of hydrophobic extracellular polymeric substances (EPS), such as proteins, polysaccharides, and eDNA, which were synthesized by bacteria themselves after adhesion and colonization on biological surfaces. They had the characteristics of dense structure, high adhesiveness and low drug permeability, and had been found in many human organs or tissues, such as the brain, heart, liver, spleen, lungs, kidneys, gastrointestinal tract, and skeleton. By releasing pro-inflammatory bacterial metabolites including endotoxins, exotoxins and interleukin, biofilms stimulated the body’s immune system to secrete inflammatory factors. These factors triggered local inflammation and chronic infections. Those were the key reason for the failure of traditional clinical drug therapy for infectious diseases.In order to cope with the increasingly severe drug-resistant infections, it was urgent to develop new therapeutic strategies for bacterial-biofilm eradication and anti-bacterial infections. Based on the nanoscale structure and biocompatible activity, nanobiomaterials had the advantages of specific targeting, intelligent delivery, high drug loading and low toxicity, which could realize efficient intervention and precise treatment of drug-resistant bacterial biofilms. This paper highlighted multiple strategies of biofilms eradication based on nanobiomaterials. For example, nanobiomaterials combined with EPS degrading enzymes could be used for targeted hydrolysis of bacterial biofilms, and effectively increased the drug enrichment within biofilms. By loading quorum sensing inhibitors, nanotechnology was also an effective strategy for eradicating bacterial biofilms and recovering the infectious symptoms. Nanobiomaterials could intervene the bacterial metabolism and break the bacterial survival homeostasis by blocking the uptake of nutrients. Moreover, energy-driven micro-nano robotics had shown excellent performance in active delivery and biofilm eradication. Micro-nano robots could penetrate physiological barriers by exogenous or endogenous driving modes such as by biological or chemical methods, ultrasound, and magnetic field, and deliver drugs to the infection sites accurately. Achieving this using conventional drugs was difficult. Overall, the paper described the biological properties and drug-resistant molecular mechanisms of bacterial biofilms, and highlighted therapeutic strategies from different perspectives by nanobiomaterials, such as dispersing bacterial mature biofilms, blocking quorum sensing, inhibiting bacterial metabolism, and energy driving penetration. In addition, we presented the key challenges still faced by nanobiomaterials in combating bacterial biofilm infections. Firstly, the dense structure of EPS caused biofilms spatial heterogeneity and metabolic heterogeneity, which created exacting requirements for the design, construction and preparation process of nanobiomaterials. Secondly, biofilm disruption carried the risk of spread and infection the pathogenic bacteria, which might lead to other infections. Finally, we emphasized the role of nanobiomaterials in the development trends and translational prospects in biofilm treatment.

Objective:To study the clustered regularly interspaced short palindromic repeats (CRISPR) genotype of Yersinia pestis and its regional distribution characteristics in natural plague focus of Tibet Autonomous Region. Methods:A total of 125 representative Yersinia pestis strains isolated from natural plague focus in Tibet Autonomous Region at different times, regions, hosts and vectors were selected as experimental strains, and the phenol chloroform mixed extraction method was used to extract Yersinia pestis DNA. Three pairs of CRISPR primers (for YPa, YPb, YPc locus) were used to amplify the DNA of the experimental strains, and the CRISPR genotype of Yersinia pestis was determined by sequencing. Results:All 125 strains of Yersinia pestis had three CRISPR locus: YPa, YPb, and YPc. A total of 18 spacer were found, including 8 in YPa loci, 6 in YPb loci, and 4 in YPc loci. Two new types of spacers had been discovered, namely b52 and c14. CRISPR typing revealed 10 genotypes, including G1, G7, G7-b4''', G7-b52, G7-c2 -, G8, G22, G22-a4 -, G22-b4''', and G22-c14, of which 6 were newly discovered genotypes. Among the 125 experimental strains, G7 was the main genotype, accounting for 65.6% (82/125), which was distributed in 6 prefecture level citys and 1 region of Tibet Autonomous Region. Next were G22 and G7-c2 - genetypes, accounting for 14.4% (18/125) and 11.2% (14/125), respectively. G22 gene type was distributed in Nagqu, Changdu, Lhasa citys, and Ngari Prefecture, while G7-c2 - genetype was distributed in Shigatse and Shannan cities. Conclusion:The CRISPR locus of Yersinia pestis in natural plague focus of Tibet Autonomous Region is highly polymorphic, and the Yersinia pestis strains with different genotypes have obvious regional distribution characteristics.

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.