Objective To investigate the effect and mechanism of miR-155-5p targeting suppressor of cytokine signaling 1(SOCS1)in regulating the Janus kinase 2(JAK2)/signal transducer and activator of transcrip-tion 3(STAT3)signaling pathway in renal injury associated with lupus nephritis(LN).Methods Thirty female MRL-faslpr lupus model mice were randomly divided into five groups(n=6 per group):the model group,the antagomir NC group,the miR-155-5p antagomir group,the miR-155-5p antagomir+shRNA control group,and the miR-155-5p antagomir+SOCS1 shRNA group.The mice were treated with adeno-associated virus vectors carrying miR-155-5p antagomir,antagomir NC,SOCS1 shRNA,or shRNA control.Additionally,six age-matched C57BL/6 mice served as a control group and received an equivalent volume of saline.Serum blood urea nitrogen(BUN)and creatinine(Scr)levels,renal histopathological changes,and the expression levels of miR-155-5p,SOCS1,phosphorylated JAK2(p-JAK2),and phosphorylated STAT3(p-STAT3)in renal tissues were evaluated.Results Compared with the normal group,the model group exhibited significantly elevated levels of BUN,Scr,miR-155-5p,p-JAK2,and p-STAT3 proteins in the kidneys(P<0.01),while the expression level of SOCS1 was markedly reduced(P<0.01).Compared with both the model group and the antagomir NC group,the miR-155-5p antagomir group showed decreased levels of BUN,Scr,miR-155-5p,p-JAK2,and p-STAT3 proteins(P<0.01),along with a significant increase in SOCS1 expression(P<0.01).Similarly,compared with the miR-155-5p antagomir group and the miR-155-5p antagomir+shRNA control group,the miR-155-5p antagomir+SOCS1 shRNA group demon-strated significantly higher levels of BUN,Scr,miR-155-5p,p-JAK2,and p-STAT3 proteins(P<0.01),while SOCS1 expression was notably decreased(P<0.01).Renal pathology analysis revealed that,compared to the normal group,the model group exhibited glomerular atrophy,extensive infiltration of inflammatory cells in the renal tubulointerstitial region,and partial renal tubular necrosis.In contrast,the miR-155-5p antagomir group showed marked improvements in glomerular atrophy,tubular necrosis,and inflammatory cell infiltration compared with the model group and antagomir NC group.Furthermore,compared with the miR-155-5p antagomir group and the miR-155-5p antagomir+shRNA control group,the miR-155-5p antagomir+SOCS1 shRNA group exhibited more severe glomerular atrophy,tubular necrosis,and inflammatory cell infiltration.Conclusion MiR-155-5p exacerbates renal damage in MRL-faslpr lupus model mice by targeting SOCS1,potentially through the activation of the JAK2/STAT3 signaling pathway.

Purpose To investigate the expression of thioredoxin-interacting protein(TXNIP)in placental tissues of gestational diabetes mellitus(GDM)and its role in lipid deposition in the placental trophoblast.Methods The pla-centa tissues of 16 GDM pregnant women and 25 women with normal glucose tolerance(NGT)were collected.Mean-while,in vitro models of high-glucose induced human chorionic trophoblast cells(HTR-8/SVneo)were established,which were divided into normal glucose control group(NG),high glucose group(HG),high glucose+si nonsense in-terference group(HG+siNC)and high glucose+TXNIP siRNA group(HG+siTXNIP).The pathological structure and morphological changes of placenta were observed by HE staining.Lipid droplet formation was detected by oil red O staining.The expression and localization of TXNIP in cells were detected by immunocytochemical EnVision method.The mRNA and protein expression levels of TXNIP and lipogenic protein SREBP1 were detected by real-time fluorescent quantitative PCR and Western blot.The relationships between TXNIP expression and lipid droplet accumulation in-duced by high glucose was analyzed.Results High glucose results in abnormal placental structure of GDM.The area of human chorionic intervillous tissue in placenta of GDM group was decreased,the size of fetal capillaries was different and the lumen was dilated.Compared with those NGT group,the accumulation of lipid droplets and the expression of TXNIP mRNA and protein in placental tissue of GDM were increased(P＜0.05).The TXNIP and SREBP1 were up-regulated and the formation of droplets increased in high glucose induced HTR-8/SVneo cells(P＜0.05).On the con-trary,TXNIP siRNA transfection reversed the gene expression level and lipid deposition in high glucose induced cells(P＜0.05).Conclusion TXNIP is involved in abnormal lipid deposition in the placental trophoblast of GDM.

Purpose To investigate the expression of thioredoxin-interacting protein(TXNIP)in placental tissues of gestational diabetes mellitus(GDM)and its role in lipid deposition in the placental trophoblast.Methods The pla-centa tissues of 16 GDM pregnant women and 25 women with normal glucose tolerance(NGT)were collected.Mean-while,in vitro models of high-glucose induced human chorionic trophoblast cells(HTR-8/SVneo)were established,which were divided into normal glucose control group(NG),high glucose group(HG),high glucose+si nonsense in-terference group(HG+siNC)and high glucose+TXNIP siRNA group(HG+siTXNIP).The pathological structure and morphological changes of placenta were observed by HE staining.Lipid droplet formation was detected by oil red O staining.The expression and localization of TXNIP in cells were detected by immunocytochemical EnVision method.The mRNA and protein expression levels of TXNIP and lipogenic protein SREBP1 were detected by real-time fluorescent quantitative PCR and Western blot.The relationships between TXNIP expression and lipid droplet accumulation in-duced by high glucose was analyzed.Results High glucose results in abnormal placental structure of GDM.The area of human chorionic intervillous tissue in placenta of GDM group was decreased,the size of fetal capillaries was different and the lumen was dilated.Compared with those NGT group,the accumulation of lipid droplets and the expression of TXNIP mRNA and protein in placental tissue of GDM were increased(P＜0.05).The TXNIP and SREBP1 were up-regulated and the formation of droplets increased in high glucose induced HTR-8/SVneo cells(P＜0.05).On the con-trary,TXNIP siRNA transfection reversed the gene expression level and lipid deposition in high glucose induced cells(P＜0.05).Conclusion TXNIP is involved in abnormal lipid deposition in the placental trophoblast of GDM.

Objective To screen the anti-Streptococcus pneumoniae(Spn)active ingredients in vitro from different po-lar parts of Pilea peltata,and to examine the combined antibacterial effect of the active ingredient and amoxicillin(AMX).Methods A 96-well plate microdilution method was used to determine the minimum inhibitory concentration(MIC)of different polar parts;the most active polar part was separated by preparative high-performance liquid chromatography,and the active ingre-dients were identified using spectral technology.The fractional inhibitory concentration(FIC)of active ingredients and AMX was determined by the 96-well plate chessboard microdilution method.The crystal violet method was used to investigate the effect of ac-tive ingredients on Spn biofilm.The effect of active ingredients on the appearance and morphology of Spn was investigated under the electron microscope.Results The MICs of the petroleum ether part,chloroform part,ethyl acetate part,n-butanol part,and water part were 1.000,1.000,0.500,1.000,and 2.000 mg·mL-1 respectively,among which the ethyl acetate part had the stron-gest antibacterial activity.Three compounds were isolated from ethyl acetate,namely 5,7,3',4'-tetramethoxyflavone 1,8-O-(p-coumaroyl)-1(10)E,4(5)E-humuladien-8-ol 2 and 1-O-p-coumaroyl copaborneol 3.These compounds were all isolated for the first time from Pilea peltate,their MICs against Spn were 200.000,50.000,and 25.000 μg·mL-1 respectively,and the compound 3 had the strongest antibacterial activity;the FIC value of AMX and compound 3 was 0.50,which had a synergistic antibacterial effect on Spn.Both AMX and compound 3 had inhibitory effects on Spn biofilm,but the biofilm inhibition rate of compound 3(59.10±1.04％)was significantly lower than AMX(87.38±0.84)％(P＜0.01);Moreover,there was no significant difference in biofilm inhibition rate between the combination of the two and AMX(P＞0.05).The scanning electron microscope results showed that the bacterial cells in the compound 3 group had a smooth surface but varying degrees of depression.The surface of the bacteri-al cells in the AMX group and the AMX combined compound 3 group showed severe swelling and rupture.Conclusions Fla-vonoids and sesquiterpenoids are both the anti-Spn active components of Pilea peltate.Among them,sesquiterpenoids have more potent antibacterial activity,and their antibacterial action mechanism is related to inhibiting bacterial biofilms.Compound 3 and AMX have a synergistic antibacterial effect on Spn,but its mechanism of action is not by enhancing biofilm inhibition;although compound 3 cannot destroy the cell wall of Spn,it still has a negative impact on the appearance of the bacteria.

Objective:To explore the effects of simultaneous transplantation of multiple foot flaps in repairing defects of varying degrees on the palmar side of multiple fingers.Methods:This study was a retrospective observational study. From February 2020 to March 2023, 11 patients aged 23-52 years with defects on the palmar side of multiple fingers (with 38 affected fingers) meeting the inclusion criteria were hospitalized at Longgang Orthopedics Hospital of Shenzhen, including 8 males (with 31 affected fingers) and 3 females (with 7 affected fingers). All affected fingers sustained skin and soft tissue defects, along with exposed deep tissue such as finger bones and tendons, and 2 thumbs exhibited nail bed and distal phalanx defects. The defect area of each finger ranged from 1.5 cm×1.0 cm to 5.5 cm×3.0 cm. Foot flaps were designed based on the area and depth of the finger defects, and multiple foot flaps were transplanted simultaneously to repair the wounds of fingers. The area of single flap resected ranged from 2.0 cm×1.0 cm to 5.5 cm×3.0 cm. Donor site wounds were closed directly or covered using artificial dermis or split-thickness skin grafts. The number of resected flaps, the number of affected fingers repaired, and the surgical duration were recorded. The flap survival and foot donor site wound healing were observed postoperatively. The flap and donor and recipient sites recovery were observed during follow-up. At the final follow-up, the functional recovery of affected fingers was evaluated based on the trial criteria of the Chinese Medical Association's Hand Surgery Society for function evaluation of thumb and finger reconstruction, the sensory function of the flaps was assessed by the sensory function evaluation standard of the British Medical Research Council, the cold tolerance of the affected hands was evaluated with the Cold Intolerance Severity Scale, the scars at the recipient and donor sites were assessed using the Vancouver scar scale (VSS), and the function recovery of flap donor foot was evaluated with the Maryland Foot Score criteria.Results:Donor sites were selected from 16 feet with 2-4 flaps harvested from each foot. Specifically, skin and soft tissue defects in 27 affected fingers were repaired using free lateral toe flaps, skin and soft tissue defects in 9 affected fingers were repaired using free medial foot flaps, and skin and soft tissue defects with finger bone defects in 2 affected fingers were repaired using free toenail osteocutaneous flaps. The surgical duration ranged from 5.60 to 9.25 hours. Postoperatively, all transplanted flaps in affected fingers survived, and all foot donor site wounds healed. Follow-up for 12-25 months showed that the appearance, color, and texture of the flaps were similar to the surrounding normal skin. The affected finger pulp was full with the fingertip having restored pain and touch sensation. There was no pain in the donor site of foot, and the walking ability of patients was not affected. At the final follow-up, the functional recovery was evaluated as excellent for 36 affected fingers and good for 2 affected fingers. The sensory function rating of the flaps was graded as S3-S4, and all affected fingers were mild intolerant to cold. VSS scores of the scars at the recipient sites ranged from 1-3, and VSS scores of the scars at the donor sites ranged from 1-5. The functional recovery of all flap donor feet was excellent.Conclusions:Simultaneous transplantation of multiple foot flaps is an effective treatment method for repairing defects of varying degrees on the palmar side of multiple fingers, resulting in excellent aesthetic and functional recovery of the affected fingers while causing minimal damage to the donor site.

Objective:To evaluate the association between heatwaves and fall-related mortality.Methods:A total of 61 421 fall-related mortality from 2013 to 2022 in 7 provinces of China were included in a time-stratified case-crossover design, with daily meteorological data derived from the fifth generation European Reanalysis dataset produced by the European Centre for Medium-Range Weather Forecasts. Conditional logistic regression chimeric distributed lag nonlinear model was used to analyze the association between heatwaves and fall-related mortality and stratified analysis was conducted according to gender and age.Results:Heatwaves were associated with an increased risk of fall-related morality. The risk of fall-related mortality during heatwaves was higher than during non-heatwave periods ( OR=1.11, 95% CI: 1.05-1.18). The attributable fraction of fall-related motality due to heatwaves was 10.25% (95% CI: 4.49%-15.36%). For each 1 ℃ increase above the heatwave threshold, the risk of fall-related mortality increased by 34% ( OR=1.34, 95% CI: 1.02-1.76). The effect of heatwave duration on fall-related mortality was not statistically significant. Stratified analyses indicated that women experienced a higher risk of fall-related mortality during heatwaves ( OR=1.13, 95% CI: 1.04-1.22) compared to man ( OR=1.10, 95% CI: 1.04-1.17). Conclusions:Heatwave increases the risk of fall-related mortality, and the intensity of heatwaves modify this risk. Women are vulnerable populations.

ObjectiveTo observe the effects of Tongluo Baoshen prescription （TLBS）-containing serum on the rat podocyte injury induced by lipopolysaccharide （LPS） and explore the potential mechanisms. MethodsSD rats were used to prepare the blank serum， losartan potassium-containing serum， and low-， medium-， and high-dose TLBS-containing sera. Rat podocytes were cultured in vitro， and the effects of drug-containing sera on podocyte viability were detected by the cell counting kit-8 （CKK-8） method. The optimal intervention volume fraction of drug-containing sera and the optimal concentration of LPS for inducing the podocyte injury were determined. Rat podocytes were grouped as follows： normal control （NC， 10% blank serum）， model control （MC， 20.00 mg·L^-1 LPS+10% black serum）， losartan potassium （LP， 20.00 mg·L^-1 LPS+10% losartan potassium-containing serum）， low-dose TLBS （TLBS-L， 20.00 mg·L^-1 LPS+10% low-dose TLBS-containing serum）， medium-dose TLBS （TLBS-M， 20.00 mg·L^-1 LPS+10% medium-dose TLBS-containing serum）， and high-dose TLBS （TLBS-H， 20.00 mg·L^-1 LPS+10% high-dose TLBS-containing serum）， and the interventions lasted for 48 h. The ultrastructure of podocytes was observed under a transmission electron microscope. The podocyte apoptosis was detected by the terminal deoxynucleoitidyl transferase mediated nick-end labeling （TUNEL） kit. Immunofluorescence was used to detect the expression of gasdermin D N-terminal fragment （GSDMD-NT） in podocytes. The mRNA and protein levels of G protein-coupled receptor family C group 5 member B （GPRC5B）， nuclear factor-κB （NF-κB） p50， NF-κB p52， NF-κB p65， Rel B， c-Rel， NOD-like receptor protein 3 （NLRP3）， cysteinyl aspartate-specific protease-1 （Caspase-1）， GSDMD-NT， interleukin （IL）-1β， IL-18， nephrin， integrin α₃， and integrin β₁ in podocytes were determined by real-time quaritiative polymerase chain reaction （Real-time PCR） and Western blot， respectively. ResultsCompared with the NC group， the MC group showed reduced podocyte protrusions and organelles， segmental missing of cell membranes， increased and swollen mitochondria， irregular nuclear membranes， light chromatin， increased TUNEL fluorescence-positive nuclei （P<0.01）， obviously enhanced fluorescence intensity of GSDMD-NT， up-regulated mRNA and protein levels of GPRC5B， NF-κB p50， NF-κB p52， NF-κB p65， Rel B， c-Rel， NLRP3， caspase-1， GSDMD-NT， IL-1β， and IL-18 （P<0.01）， and down-regulated mRNA and protein levels of nephrin， integrin α₃， and integrin β₁ （P<0.01） in podocytes. Compared with the MC group， the LP， TLBS-M， and TLBS-H groups showed improved ultrastructure of podocytes with increased protrusions， intact cell membranes， reduced organelles， and alleviated mitochondrial swelling， decreased TUNEL fluorescence-positive nuclei （P<0.01）， weakened fluorescence intensity of GSDMD-NT， down-regulated mRNA and protein levels of GPRC5B， NF-κB p50， NF-κB p52， NF-κB p65， Rel B， c-Rel， NLRP3， caspase-1， GSDMD-NT， IL-1β， and IL-18 （P<0.01）， and up-regulated mRNA and protein levels of nephrin， integrin α₃， and integrin β₁ （P<0.05， P<0.01）. Moreover， the changes above were the most obvious in the TLBS-H group. ConclusionThe TLBS-containing serum can regulate the GPRC5B/NF-κB/NLRP3 pathway to inhibit pyroptosis， thereby ameliorating the podocyte injury induced by LPS.

Objective To observe the therapeutic effects of Tongluo Baoshen Prescription on IgA nephropathy rats;To explore its mechanism.Methods Totally 130 SD rats were randomly divided into a normal group(20 rats)and a modeling group(110 rats).After establishing the IgA nephropathy model,the modeling group was further randomly divided into the model group,losartan potassium group and Tongluo Baoshen Prescription low-,medium-and high-dosage groups,with 20 rats in each group.Tongluo Baoshen Prescription low-,medium-and high-dosage groups were administered at dosages of 5.3,10.6 and 21.2 g/kg respectively,the losartan potassium group was given with the dosage of 5 mg/kg,the normal group and model group were given an equivalent amount of distilled water by gavage once daily.Blood,urine and kidney tissue samples were collected after 4 and 8 weeks of administration.The hemoglobin content was detected,urinary IL-1β,integrin α3β1 and serum albumin contents were detected by ELISA,and the mRNA and protein expressions of NF-κB p52,NF-κB p65,Rel B,c-Rel and Desmin in renal tissue were detected by RT-qPCR and Western blot,the apoptosis of renal tissue at 8 weeks of administration was detected by TUNEL staining,the expression of C3c in renal tissue was detected by immunofluorescence,the co-expression of Gprc5b,Caspase-1,NLRP3 and Nephrin were detected by immunofluorescence double labeling,the expression of Gprc5b and Nephrin in renal tissue were detected by immunohistochemistry.Results Compared with the normal group,the model group rats showed significantly increased contents of urinary IL-1β and integrin α3β1(P<0.01),with further increases in urinary integrin α3β1 over time(P<0.05);the mRNA and protein expressions of NF-κB p52,NF-κB p65,Rel B,c-Rel and Desmin in renal tissue significantly increased(P<0.01),and the proportion of apoptosis-positive cells in renal tissue significantly increased(P<0.01),immunofluorescence results revealed that C3c exhibited granular and clumpy high-intensity deposition in the mesangial area and capillary loops of the glomeruli(P<0.01),immunofluorescence double labeling showed that the expression of Gprc5b,Caspase-1 and NLRP3 in renal tissue increased(P<0.01),while Nephrin expression significantly decreased(P<0.01),immunohistochemistry analysis showed that the positive expression of Gprc5b in renal tissue significantly increased(P<0.01),while Nephrin significantly decreased(P<0.01).Compared with the model group,the urinary IL-1β and integrin α3β1 contents in the losartan potassium group and Tongluo Baoshen Prescription groups reduced after 4 and 8 weeks of treatment(P<0.05,P<0.01);the mRNA and protein expressions of NF-κB p52,NF-κB p65,Rel B,c-Rel and Desmin in renal tissue decreased(P<0.05,P<0.01),and the proportion of apoptosis-positive cells in renal tissue decreased(P<0.05),the C3c deposition in renal tissue was diminished(P<0.05,P<0.01),immunofluorescence double labeling showed that the expression of Gprc5b,Caspase-1 and NLRP3 in renal tissue were decreased(P<0.05,P<0.01),while Nephrin expression increased(P<0.05,P<0.01),immunohistochemistry analysis showed that the positive expression of Gprc5b in renal tissue decreased(P<0.05,P<0.01),while Nephrin expression increased(P<0.05,P<0.01).Conclusion Tongluo Baoshen Prescription has a protective effect on the kidney of IgA nephropathy rats,and it can improve podocyte injury.The mechanism may be related to the inhibition of the Gprc5b/NF-κB/NLRP3 pathway.

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.