OBJECTIVE: Peritoneal fibrosis (PF) is an adverse event that occurs during long-term peritoneal dialysis, significantly impairing treatment efficiency and adversely affecting patient outcomes. Astragaloside IV (AS-IV), a principal active component derived from Astragalus membranaceus (Fisch.) Bunge, has exhibited anti-inflammatory and antifibrotic effects in various settings. This study aims to investigate the potential therapeutic efficacy and mechanism of AS-IV in the treatment of PF. METHODS: The PF mouse model was established by intraperitoneal injection of 4.25% peritoneal dialysis fluid (100 mL/kg). The epithelial-mesenchymal transition (EMT) of HMrSV5 cells was induced by the addition of 10 ng/mL transforming growth factor β (TGF-β). The differentially expressed genes in HMrSV5 cells treated with AS-IV were screened using transcriptome sequencing analysis. The potential targets of AS-IV were screened using network pharmacology and analyzed using molecular docking and molecular dynamics simulations. RESULTS: Administration of AS-IV at doses of 20, 40, or 80 mg/kg effectively mitigated the increase in peritoneal thickness and the development of fibrosis in mice with PF. The expression of the fibrosis marker α-smooth muscle actin in the peritoneum was significantly decreased in AS-IV-treated mice. The treatment of AS-IV (10, 20, and 40 μmol/L) significantly delayed the EMT of HMrSV5 cells induced by TGF-β, as demonstrated by the decreased number of 5-ethynyl-2'-deoxyuridine-positive cells, reduced migrated area, and decreased expression of fibrosis markers. A total of 460 differentially expressed genes were detected in AS-IV-treated HMrSV5 cells through transcriptome sequencing, with notable enrichment in the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)-AKT serine/threonine kinase 1 (AKT) signaling pathway. The reduced levels of phosphorylated PI3K (p-PI3K) and p-AKT were detected in HMrSV5 cells with AS-IV treatment. Epidermal growth factor receptor (EGFR) was predicted as a direct target of AS-IV, exhibiting strong hydrogen bond interactions. The activation of the PI3K-AKT pathway by the compound 740Y-P, and the activation of the EGFR pathway by NSC 228155 each partially counteracted the inhibitory effect of AS-IV on the EMT of HMrSV5 cells. CONCLUSION AS-IV delayed the EMT process in peritoneal mesothelial cells and slowed the progression of PF, potentially serving as a therapeutic agent for the early prevention and treatment of PF. Please cite this article as: Huang Y, Chu CL, Qiu WH, Chen JY, Cao LX, Ji SY, Zhu B, Wang GK, Shen QQ. Astragaloside IV delayed the epithelial-mesenchymal transition in peritoneal fibrosis by inhibiting the activation of EGFR and PI3K-AKT pathways. J Integr Med. 2025; 23(6):694-705.
Epithelial-Mesenchymal Transition/drug effects* ; Animals ; Saponins/pharmacology* ; Triterpenes/pharmacology* ; Mice ; Peritoneal Fibrosis/pathology* ; Proto-Oncogene Proteins c-akt/metabolism* ; ErbB Receptors/metabolism* ; Phosphatidylinositol 3-Kinases/metabolism* ; Signal Transduction/drug effects* ; Male ; Humans ; Molecular Docking Simulation ; Cell Line ; Mice, Inbred C57BL

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 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 The aim of this study is to explore the potential modulatory role of quercetin against Endotoxin or lipopolysaccharide (LPS) induced septic cardiac dysfunction.Methods Specific pathogen-free chicken embryos (n = 120) were allocated untreated control, phosphate buffer solution (PBS) vehicle, PBS with ethanol vehicle, LPS (500 ng/egg), LPS with quercetin treatment (10, 20, or 40 nmol/egg, respectively), Quercetin groups (10, 20, or 40 nmol/egg). Fifteen-day-old embryonated eggs were inoculated with abovementioned solutions via the allantoic cavity. At embryonic day 19, the hearts of the embryos were collected for histopathological examination, RNA extraction, real-time polymerase chain reaction, immunohistochemical investigations, and Western blotting.Results They demonstrated that the heart presented inflammatory responses after LPS induction. The LPS-induced higher mRNA expressions of inflammation-related factors (TLR4, TNFα, MYD88, NF-κB1, IFNγ, IL-1β, IL-8, IL-6, IL-10, p38, MMP3, and MMP9) were blocked by quercetin with three dosages. Quercetin significantly decreased immunopositivity to TLR4 and MMP9 in the treatment group when compared with the LPS group. Quercetin significantly decreased protein expressions of TLR4, IFNγ, MMP3, and MMP9 when compared with the LPS group. Quercetin treatment prevented LPS-induced increase in the mRNA expression of Claudin 1 and ZO-1, and significantly decreased protein expression of claudin 1 when compared with the LPS group. Quercetin significantly downregulated autophagy-related gene expressions (PPARα, SGLT1, APOA4, AMPKα1, AMPKα2, ATG5, ATG7, Beclin-1, and LC3B) and programmed cell death (Fas, Bcl-2, CASP1, CASP12, CASP3, and RIPK1) after LPS induction. Quercetin significantly decreased immunopositivity to APOA4, AMPKα2, and LC3-II/LC3-I in the treatment group when compared with the LPS group. Quercetin significantly decreased protein expressions of AMPKα1, LC3-I, and LC3-II. Quercetin significantly decreased the protein expression to CASP1 and CASP3 by immunohistochemical investigation or Western blotting in treatment group when compared with LPS group.Conclusion Quercetin alleviates cardiac inflammation induced by LPS through modulating autophagy, programmed cell death, and myocardiocytes permeability.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objectives:To investigate the intravascular ultrasound(IVUS)evaluated efficacy of the"L-sandwich"technique in the percutaneous coronary intervention treatment of true bifurcation lesions of coronary artery. Methods:Ninety-nine patients with true bifurcation lesions(medina type 1.1.1)of the coronary arteries were divided into the L-sandwich group(n=38),the double-stent group(n=32),and the main vessel(MV)single-stent with side branch(SB)drug-coated balloon(DCB)only group(n=29).The primary study endpoint was the loss of late lumen area(LLAL)in the MV,SB ostium and SB shaft at 12 months,and the secondary endpoints were minimum lumen area(MLA)at each site and major adverse cardiac events(MACE)at 12 months.As this is a proof-of-concept study,statistical analyses were performed in the as-treated(AT)analysis set. Results:At 12-month follow-up,there was no statistically significant difference in the MV LLAL among patients in the"L-sandwich"technique group,the double stent technique group,and the MV DES with SB DCB technique group([0.12±0.42]mm2 vs.[0.07±0.38]mm2 vs.[-0.01±0.31]mm2,P=0.419).Similarly,there was no statistically significant difference in the LLAL at the SB shaft([-0.11±0.45]mm2 vs.[-0.10±0.28]mm2 vs.[0.24±1.04]mm2,P=0.078],with the maximum LLAL observed in the double stent technique group and the minimum in the"L-sandwich"technique group([-0.48±0.78]mm2 vs.[0.45±0.64]mm2 vs.[0.14±1.37]mm2,P<0.001).The MV MLA was similar among the three groups([8.39±1.65]mm2 vs.[8.28±0.98]mm2 vs.[8.02±1.37]mm2,P=0.565),while the maximum MLA at the SB ostium was observed in the double stent technique group and the minimum in the MV DES with SB DCB group([5.08±0.74]mm2 vs.[5.63±0.80]mm2 vs.[3.57±1.35]mm2,P<0.001).In terms of MLA at the SB shaft,the"L-sandwich"technique group was similar to the double stent technique group,while the MV DES with SB DCB group exhibited the minimum MLA([5.94±0.72]mm2 vs.[5.86±0.59]mm2 vs.[3.74±1.07]mm2,P<0.001).Two patients in the double stent technique group underwent target vessel revascularization,there was no MACE in the other two groups(P=0.118). Conclusions:The"L-sandwich"technique is safe and feasible for the treatment of coronary bifurcation lesions.Compared with double-stent group,the SB ostium has a smaller LLAL at the time of review,and there is no significant difference in the MLA of each site,and the operation steps are significantly simplified.Use of the"L-sandwich"technique is associated with a better branching benefit compared with MV single-stent group.The"L-sandwich"technique could be used as a remedial procedure for severe entrapment in the setting of branching with DCB alone.

Purpose To investigate the predictive value of chest CT-based radiomics for spread through air spaces in stage T1 peripheral type lung cancer.Materials and Methods A total of 173 patients with surgically pathologically confirmed stage T1 non-small cell lung cancer were retrospectively collected and divided into positive group(49 cases)and negative group(124 cases)according to the presence or absence of spread through air spaces.All lesions were randomly divided into training set(122 cases)and validation set(51 cases)according to the ratio of 7∶3.The primary area of lung cancer(the main body of the lesion),the peripheral infiltrative area(a 5-mm annular area expanding outward along the edge of the lesion)and the tumor margin area(a 5-mm annular area retracting inward along the edge of the lesion)were used as areas of interest to extract imaging histological features.Three imaging histological models were established for the primary area of lung cancer,the peripheral infiltrative area and the tumor margin area,and combined with the morphological features of CT to establish three combined models.The efficacy of each model was evaluated and the optimal model was selected.Results The lobulation signs of positive group was significantly more than that of negative group(χ2=9.946,P=0.002).The area under the curve(AUC)of the imaging histological model based on the three regions of interest were 0.899,0.825,0.840 for the training group and 0.876,0.811 and 0.832 for the validation group,respectively.The model with the highest AUC was the primary tumor imaging model(P=0.043,P<0.001,P=0.017),the AUC of the combined model established by adding the lobar sign were 0.917,0.835 and 0.851,respectively.The AUC of the three regions of interest in the validation group were 0.912,0.832,and 0.845 and the highest AUC was found in the primary tumor area(P<0.001,P=0.017,P=0.049).Conclusion It is feasible to study lung cancer with airway metastasis via CT-based radiomics,taken lobulation signs as the risk predictive factor.

OBJECTIVE: To investigate the effectiveness of one-stage total knee arthroplasty (TKA) in the treatment of advanced active knee tuberculosis. METHODS: The clinical data of 38 patients with advanced active knee tuberculosis who received one-stage TKA between January 2011 and December 2020 were retrospectively analyzed. There were 20 males and 18 females. The age ranged from 20 to 84 years, with an average of 52.8 years. The body mass index ranged from 17 to 36 kg/m ², with an average of 23.05 kg/m ². The preoperative C reactive protein (CRP) was (23.49±4.72) mg/L, erythrocyte sedimentation rate (ESR) was (45.95±8.82) mm/1 h. The Hospital for Special Surgery (HSS) score was 48.8±9.1. During the operation, the infected lesions of the knee joint were completely removed, and the operative area was repeatedly soaked with 3% hydrogen peroxide solution and 0.5% povidone iodine solution. The intraoperative pathological examination confirmed the tuberculosis of the knee joint, and systemic anti-tuberculosis treatment was performed. The operation time, postoperative hospitalization stay, postoperative anti-tuberculosis chemotherapy time, and complications were recorded. CRP and ESR were recorded and compared before and after operation. Anteroposterior and lateral X-ray films of the knee joint were taken to evaluate whether the prosthesis had signs of loosening and sinking, and to determine whether there was recurrence of tuberculosis. The knee joint function was evaluated by HSS score. With treatment failure due to any reason as the end event, the survival time of prosthesis was analyzed by Kaplan-Meier survival curve. RESULTS: All operations were successfully completed without fracture, vascular and nerve injury, deep vein thrombosis, and other complications. All incisions healed by first intention after operation. The operation time ranged from 80 to 135 minutes, with an average of 102.76 minutes; postoperative hospitalization stay was 5-16 days, with an average of 9.7 days; the duration of postoperative anti-tuberculosis chemotherapy ranged from 1 to 18 months, and the median duration was 12 months. All 38 cases were followed up 3-133 months (mean, 63.7 months). At last follow-up, CRP was (4.88±1.24) mg/L and ESR was (13.00±2.97) mm/1 h, both of which were significantly lower than those before operation ( t=20.647, P<0.001; t=20.886, P<0.001). During the follow-up, 3 patients (7.89%) had tuberculosis recurrence. Two patients had tuberculosis recurrence due to withdrawal of anti-tuberculosis chemotherapy at 1 and 2 months after operation, respectively. One patient was cured after debridement, preservation of prosthesis and anti-tuberculosis chemotherapy for 12 months, and 1 patient was cured after oral administration of anti-tuberculosis drugs for 12 months. Another 1 patient had recurrent tuberculosis and mixed infection ( Corynebacterium gehreni) at 2 months after operation, and the infection was not controlled after debridement, and finally the thigh was amputated. Except for the patients with recurrent infection, no complications such as prosthesis loosening, periprosthetic fracture, and periprosthetic infection were found. At last follow-up, the HSS score of the knee joint was 86.8±4.8, and the knee joint function significantly improved when compared with that before operation ( t=-31.198, P<0.001). Prosthesis survival time was (122.57±5.77) months [95% CI (111.25, 133.88) months], and the 10-year survival rate was 92.1%. CONCLUSION One-stage TKA combined with postoperative antituberculous chemotherapy in the treatment of advanced active knee tuberculosis can achieve satisfactory infection control and joint function.
Female ; Male ; Humans ; Young Adult ; Adult ; Middle Aged ; Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Knee ; Retrospective Studies ; Knee Joint ; Tuberculosis ; Antitubercular Agents/therapeutic use*

Objective:To analyze the risk factors leading to the failure of early periprosthetic joint infection (PJI) treated by debridement, antibiotics and implant retention (DAIR) combined with intra-articular injection of antibiotics.Methods:A total of 100 patients who received DAIR combined with intra-articular injection of antibiotics between January 2010 and October 2020 in the Department of Orthopaedics, First Affiliated Hospital of Xinjiang Medical University, were retrospectively analyzed. There were 47 males and 53 females, with an average age of 62.8±13.0 years (26-84 years). 75 patients were diagnosed as PJI after primary surgery while 25 PJI after revision or debridement, involving 41 hips and 59 knees. According to the clinical outcomes, the patients were divided into the cured group (78 cases) and the uncured group (22 cases). Risk factors were screened by univariate analysis on their gender, age, body mass index, site of infection (hip/knee), synovial white blood cell count, erythrocyte sedimentation rate (ESR), C reactive protein (CRP), time of infection, types of pathogenic bacteria (gram-positive bacteria, gram-negative bacteria or fungi), preoperative sinus tract and previous surgical history. For the factors with P<0.20, multivariate binary logistic regression analysis was performed to determine the independent risk factors. Kaplan-Meier survival curve was drawn and any cause that led to treatment failure was seen as the end point event. Calculate prosthetic survival time and 10-year survival rate. Results:The average follow-up was 59.8±40.6 months (0.3-129.0 months). The infection control rate of DAIR combined with intra-articular injection of antibiotics in the treatment of early PJI was 78% (78/100). The univariate analysis showed that the successful rate of non-fungal infection group (81%, 77/95) was significantly higher than the fungal infection group (20%, 1/5) and the successful rate of the group without previous surgical history (85.3%, 64/75) was significantly higher than that with previous surgical history (56.0%, 14/25, χ 2=7.07, P=0.008; χ 2=9.40, P=0.002). The multivariate binary Logistic regression analysis showed that fungal infection [ OR=0.08, 95% CI(0.01, 0.79), P=0.031] and history of previous surgical intervention [ OR=0.25, 95% CI(0.09, 0.73), P=0.001] were independent risk factors for treatment failure. Kaplan-Meier survival curves showed that the survival time of the prosthesis was 96.83±5.30 months, and the 10-year survival rate was 68.1%. Meanwhile, the survival rate of patients with fungal infection and previous surgical history was significantly lower than that of patients without fungal infection or previous surgical history, the difference was statistically significant (χ 2=15.49, P<0.001; χ 2=8.91, P=0.030). Conclusion:The time of PJI, bacterial virulence and species, and preoperative inflammatory indicators had no effect on the outcome of DAIR combined with intra-articular injection of antibiotics in the treatment of early PJI. However, DAIR was not recommended for patients with a history of surgical intervention and fungal infection.

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.