Nipah virus (NiV) and related viruses form a distinct henipavirus genus within the Paramyxoviridae family. NiV continues to spillover into the humans causing deadly outbreaks with increasing human-bat interaction. NiV encodes the large protein (L) and phosphoprotein (P) to form the viral RNA polymerase machinery. Their sequences show limited homologies to those of non-henipavirus paramyxoviruses. We report two cryo-electron microscopy (cryo-EM) structures of the Nipah virus (NiV) polymerase L-P complex, expressed and purified in either its full-length or truncated form. The structures resolve the RNA-dependent RNA polymerase (RdRp) and polyribonucleotidyl transferase (PRNTase) domains of the L protein, as well as a tetrameric P protein bundle bound to the L-RdRp domain. L-protein C-terminal regions are unresolved, indicating flexibility. Two PRNTase domain zinc-binding sites, conserved in most Mononegavirales, are confirmed essential for NiV polymerase activity. The structures further reveal anchoring of the P protein bundle and P protein X domain (XD) linkers on L, via an interaction pattern distinct among Paramyxoviridae. These interactions facilitate binding of a P protein XD linker in the nucleotide entry channel and distinct positioning of other XD linkers. We show that the disruption of the L-P interactions reduces NiV polymerase activity. The reported structures should facilitate rational antiviral-drug discovery and provide a guide for the functional study of NiV polymerase.
Nipah Virus/chemistry* ; Cryoelectron Microscopy ; Viral Proteins/genetics* ; RNA-Dependent RNA Polymerase/genetics* ; Phosphoproteins/genetics* ; Humans ; Models, Molecular ; Protein Binding

Objective To assess the risk factors for carbapenem-resistant Acinetobacter baumannii(CRAB)bloodstream infection(BSI)and 28-day short-term mortality in elderly patients,and provide reference for the pre-vention and treatment of CRAB BSI.Methods Clinical data of patients aged ≥60 years and diagnosed with AB BSI in a hospital in Yulin City from January 2013 to December 2022 were retrospectively analyzed,including demogra-phic and microbiological characteristics,as well as clinical outcomes of the patients.Variables which were significant in univariate analysis were selected for multivariate analysis using binary logistic regression model and Cox propor-tional hazards model.Independent risk factors for infection were further determined,and survival analysis was per-formed using Kaplan-Meier curve.Results A total of 150 patients were included in the study,out of which 16 pa-tients(10.7％)had CRAB BSI and 134 had carbapenem-sensitive AB(CSAB)BSI.The 28-day short-term mortali-ty of AB BSI in elderly patients was 15.3％(23/150,95％CI:9.6％-21.1％),and the short-term mortality of CRAB BSI was higher than that of CSAB([56.3％,9/16]vs[10.4％,14/134]).Deep venous catheterization(OR:15.598,95％CI:1.831-132.910)and combined infections of other sites(OR:15.449,95％CI:1.497-159.489)were related to CRAB BSI in elderly patients.The independent risk factors for 28-day mortality in elderly patients with AB BSI were hemodialysis(OR:11.856,95％CI:2.924-48.076),intensive care unit admission(OR:9.387,95％CI:1.941-45.385),and pulmonary infection being suspected source of bacteremia(OR:7.019,95％CI:1.345-36.635).Conclusion The occurrence of CRAB BSI in elderly patients is related to the combined infection of other sites and deep vein catheterization.Hemodialysis,admission to ICU,and pulmonary infection being suspected source of bacteremia are independent risk factors for the prognosis of AB BSI in elderly patients.

AIM To investigate the effects of Zhuangyao Shuanglu Tongnao Formula on neuronal apoptosis in rats with cerebral ischemia-reperfusion injury based on the study of oxidative stress and inflammatory response.METHODS The rats were randomly divided into the sham operation group,the model group,the edaravone group(3.0 mg/kg),the low,medium and high dose groups(9.0,18.0,36.0 g/kg)of Zhuangyao Shuanglu Tongnao Formula,with 18 rats in each group.The middle cerebral artery occlusion/reperfusion was conducted by thread embolism method to simulate cerebral ischemia reperfusion injury in rats followed by 6 days corresponding drugs administration.Subsequently,the rats had their neurological function deficit scored by Zeal Longa scoring method;their sizes of cerebral infarction areas measured by TTC staining;their pathological damage and apoptosis of neurons in hippocampal CA1 area of ischemic penumbra of the brain tissue detected by HE staining and TUNEL staining;their SOD activity and levels of GSH,MDA,IL-6,IL-1β,TNF-α in brain tissue detected by kits;and their protein expressions of Bax,Bcl-2,caspase-3,cleaved-capase-3,TLR4,NF-κB p65,Nrf2,HO-1 in rat brain tissue determined by Western blot.RESULTS Compared with the model group,the groups intervened with edaravone,medium and high dose of Zhuangyao Shuanglu Tongnao Formula displayed improvements in the scores of nerve function defects,the rate of cerebral infarction,the rate of neuronal apoptosis,the levels of IL-6,IL-1β,TNF-α and MDA in the ischemic penumbra of brain tissues,the protein expressions of Bax and TLR4,the ratio of cleaved-capase-3/caspase-3 and p-NF-κB p65/NF-κB p65(P＜0.05),the levels of GSH,the activity of SOD and the protein expressions of Bcl-2,Nrf2 and HO-1(P＜0.05).CONCLUSION Being an inhibitor of oxidative stress and inflammatory response,Zhuangyao Shuanglu Tongnao Formula can alleviate brain injury in rats with cerebral ischemia reperfusion injury through the inhibition of neuronal apoptosis and improvement of neural function mediated by the inhibition of TLR4/NF-κB signal pathway and activation of Nrf2/HO-1 signal pathway.

Objective:To compare the efficacy of conventional open ankle fusion and three dimensional(3D) printed guide plate assisted arthroscopic ankle fusion.Methods:A retrospective cohort study was performed on 256 patients with advanced traumatic ankle arthritis, who were admitted to the Department of Orthopaedics, Shanghai Sixth People′s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from May 2018 to February 2023 and underwent ankle fusion procedures. The study cohort comprised 119 males and 137 females, with an age of (59.6±9.5) years (range: 37 to 83 years). Among them, 175 cases underwent internal fixation with plates and screws (58 cases through the combined medial and lateral approach, and 117 cases through the simple lateral approach), 48 cases underwent internal fixation with screws through the anterior approach (conventional open group), and 33 cases underwent minimally invasive arthroscopic ankle fusion assisted by 3D printed guide plate (3D printed guide plate arthroscopy group). Propensity score matching was employed to achieve a 1∶1 match(caliper value=0.02) between the baseline characteristics of patients in the 3D printed guide plate arthroscopy group and the conventional open group. Perioperative and follow-up data between the two groups were compared using the t-test, Mann-Whitney U test, Wilcoxon signed rank test, χ2 test or corrected χ2 test as appropriate. Results:Matching was successfully achieved with 20 cases in both the 3D printed guide plate arthroscopy group and the conventional open group, and there were no statistically significant differences in baseline characteristics between the two groups (all P>0.05). The operation time in the 3D printed guide plate arthroscopy group was significantly longer than that in the conventional open group ((88.9±5.6) minutes vs. (77.9±11.7) minutes; t=-2.392, P=0.022), while the frequency of intraoperative fluoroscopies ((1.7±0.8) times vs. (5.2±1.2) times; t=10.604, P<0.01) and length of hospitalization ((5.5±0.9) days vs. (6.4±1.5) days; t=2.480, P=0.018) were significantly lower in the 3D printed guide plate arthroscopy group compared to the conventional open group. The fusion rate was 95.0% (19/20) in the 3D printed guide plate arthroscopy group and 85.0% (17/20) in the conventional open group, with no statistically significant difference between the two groups ( χ2=0.278, P=0.598). The fusion time was (12.1±2.0) weeks in the conventional open group and (11.1±1.7) weeks in the 3D printed guide plate arthroscopy group, with no statistically significant difference between the two groups ( t=1.607, P=0.116). At the final follow-up, the American Orthopedic Foot and Ankle Society ankle hindfoot scale was (72.6±5.5)points in the 3D printed guide plate arthroscopy group and (70.5±5.8)points in the conventional open group, with no statistically significant difference between the two groups ( t=-1.003, P=0.322). The pain visual analogue score of the 3D printed guide plate arthroscopy group was ( M(IQR)) 1.50 (1.00) points, lower than that of the conventional open group by 3.00 (1.00) points, with statistically significant differences ( Z=-3.937, P<0.01). There was no significant difference in complication rate between the conventional open group and the 3D printed guide plate arthroscopy group (25.0%(5/20) vs. 5.0%(1/20), χ2=1.765， P=0.184). Conclusion:3D printed guide plate assisted arthroscopic ankle fusion exhibited several advantages, including reduced frequency of fluoroscopies, alleviation of postoperative pain, and decreased complications and length of hospitalization.

Objective:To compare the efficacy of conventional open ankle fusion and three dimensional(3D) printed guide plate assisted arthroscopic ankle fusion.Methods:A retrospective cohort study was performed on 256 patients with advanced traumatic ankle arthritis, who were admitted to the Department of Orthopaedics, Shanghai Sixth People′s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from May 2018 to February 2023 and underwent ankle fusion procedures. The study cohort comprised 119 males and 137 females, with an age of (59.6±9.5) years (range: 37 to 83 years). Among them, 175 cases underwent internal fixation with plates and screws (58 cases through the combined medial and lateral approach, and 117 cases through the simple lateral approach), 48 cases underwent internal fixation with screws through the anterior approach (conventional open group), and 33 cases underwent minimally invasive arthroscopic ankle fusion assisted by 3D printed guide plate (3D printed guide plate arthroscopy group). Propensity score matching was employed to achieve a 1∶1 match(caliper value=0.02) between the baseline characteristics of patients in the 3D printed guide plate arthroscopy group and the conventional open group. Perioperative and follow-up data between the two groups were compared using the t-test, Mann-Whitney U test, Wilcoxon signed rank test, χ2 test or corrected χ2 test as appropriate. Results:Matching was successfully achieved with 20 cases in both the 3D printed guide plate arthroscopy group and the conventional open group, and there were no statistically significant differences in baseline characteristics between the two groups (all P>0.05). The operation time in the 3D printed guide plate arthroscopy group was significantly longer than that in the conventional open group ((88.9±5.6) minutes vs. (77.9±11.7) minutes; t=-2.392, P=0.022), while the frequency of intraoperative fluoroscopies ((1.7±0.8) times vs. (5.2±1.2) times; t=10.604, P<0.01) and length of hospitalization ((5.5±0.9) days vs. (6.4±1.5) days; t=2.480, P=0.018) were significantly lower in the 3D printed guide plate arthroscopy group compared to the conventional open group. The fusion rate was 95.0% (19/20) in the 3D printed guide plate arthroscopy group and 85.0% (17/20) in the conventional open group, with no statistically significant difference between the two groups ( χ2=0.278, P=0.598). The fusion time was (12.1±2.0) weeks in the conventional open group and (11.1±1.7) weeks in the 3D printed guide plate arthroscopy group, with no statistically significant difference between the two groups ( t=1.607, P=0.116). At the final follow-up, the American Orthopedic Foot and Ankle Society ankle hindfoot scale was (72.6±5.5)points in the 3D printed guide plate arthroscopy group and (70.5±5.8)points in the conventional open group, with no statistically significant difference between the two groups ( t=-1.003, P=0.322). The pain visual analogue score of the 3D printed guide plate arthroscopy group was ( M(IQR)) 1.50 (1.00) points, lower than that of the conventional open group by 3.00 (1.00) points, with statistically significant differences ( Z=-3.937, P<0.01). There was no significant difference in complication rate between the conventional open group and the 3D printed guide plate arthroscopy group (25.0%(5/20) vs. 5.0%(1/20), χ2=1.765， P=0.184). Conclusion:3D printed guide plate assisted arthroscopic ankle fusion exhibited several advantages, including reduced frequency of fluoroscopies, alleviation of postoperative pain, and decreased complications and length of hospitalization.

Objective To investigate the distribution and antimicrobial resistance profiles of the common pathogens isolated from urine from 2015 to 2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods The bacterial strains were isolated from urine and identified routinely in 51 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Antimicrobial susceptibility was determined by Kirby-Bauer method,automatic microbiological analysis system and E-test according to the unified protocol.Results A total of 261 893 nonduplicate strains were isolated from urine specimen from 2015 to 2021,of which gram-positive bacteria accounted for 23.8％(62 219/261 893),and gram-negative bacteria 76.2％(199 674/261 893).The most common species were E.coli(46.7％),E.faecium(10.4％),K.pneumoniae(9.8％),E.faecalis(8.7％),P.mirabilis(3.5％),P.aeruginosa(3.4％),SS.agalactiae(2.6％),and E.cloacae(2.1％).The strains were more frequently isolated from inpatients versus outpatients and emergency patients,from females versus males,and from adults versus children.The prevalence of ESBLs-producing strains in E.coli,K.pneumoniae and P.mirabilis was 53.2％,52.8％and 37.0％,respectively.The prevalence of carbapenem-resistant strains in E.coli,K.pneumoniae,P.aeruginosa and A.baumannii was 1.7％,18.5％,16.4％,and 40.3％,respectively.Lower than 10％of the E.faecalis isolates were resistant to ampicillin,nitrofurantoin,linezolid,vancomycin,teicoplanin and fosfomycin.More than 90％of the E.faecium isolates were ressitant to ampicillin,levofloxacin and erythromycin.The percentage of strains resistant to vancomycin,linezolid or teicoplanin was＜2％.The E.coli,K.pneumoniae,P.aeruginosa and A.baumannii strains isolated from ICU inpatients showed significantly higher resistance rates than the corresponding strains isolated from outpatients and non-ICU inpatients.Conclusions E.coli,Enterococcus and K.pneumoniae are the most common pathogens in urinary tract infection.The bacterial species and antimicrobial resistance of urinary isolates vary with different populations.More attention should be paid to antimicrobial resistance surveillance and reduce the irrational use of antimicrobial agents.

Objective To understand the distribution and changing resistance profiles of clinical isolates of Enterococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Enterococcus according to the unified protocol of CHINET program by automated systems,Kirby-Bauer method,or E-test strip.The results were interpreted according to the Clinical & Laboratory Standards Institute(CLSI)breakpoints in 2021.WHONET 5.6 software was used for statistical analysis.Results A total of 124 565 strains of Enterococcus were isolated during the 7-year period,mainly including Enterococcus faecalis(50.7％)and Enterococcus faecalis(41.5％).The strains were mainly isolated from urinary tract specimens(46.9％±2.6％),and primarily from the patients in the department of internal medicine,surgery and ICU.E.faecium and E.faecalis strains showed low level resistance rate to vancomycin,teicoplanin and linezolid(≤3.6％).The prevalence of vancomycin-resistant E.faecalis and E.faecium was 0.1％and 1.3％,respectively.The prevalence of linezolid-resistant E.faecalis increased from 0.7％in 2015 to 3.4％in 2021,while the prevalence of linezolid-resistant E.faecium was 0.3％.Conclusions The clinical isolates of Enterococcus were still highly susceptible to vancomycin,teicoplanin,and linezolid,evidenced by a low resistance rate.However,the prevalence of linezolid-resistant E.faecalis was increasing during the 7-year period.It is necessary to strengthen antimicrobial resistance surveillance to effectively identify the emergence of antibiotic-resistant bacteria and curb the spread of resistant pathogens.

Objective To examine the changing antimicrobial resistance profile of Enterobacter spp.isolates in 53 hospitals across China from 2015 t0 2021.Methods The clinical isolates of Enterobacter spp.were collected from 53 hospitals across China during 2015-2021 and tested for antimicrobial susceptibility using Kirby-Bauer method or automated testing systems according to the CHINET unified protocol.The results were interpreted according to the breakpoints issued by the Clinical & Laboratory Standards Institute(CLSI)in 2021(M100 31st edition)and analyzed with WHONET 5.6 software.Results A total of 37 966 Enterobacter strains were isolated from 2015 to 2021.The proportion of Enterobacter isolates among all clinical isolates showed a fluctuating trend over the 7-year period,overall 2.5％in all clinical isolates amd 5.7％in Enterobacterale strains.The most frequently isolated Enterobacter species was Enterobacter cloacae,accounting for 93.7％(35 571/37 966).The strains were mainly isolated from respiratory specimens(44.4±4.6)％,followed by secretions/pus(16.4±2.3)％and urine(16.0±0.9)％.The strains from respiratory samples decreased slightly,while those from sterile body fluids increased over the 7-year period.The Enterobacter strains were mainly isolated from inpatients(92.9％),and only(7.1±0.8)％of the strains were isolated from outpatients and emergency patients.The patients in surgical wards contributed the highest number of isolates(24.4±2.9)％compared to the inpatients in any other departement.Overall,≤ 7.9％of the E.cloacae strains were resistant to amikacin,tigecycline,polymyxin B,imipenem or meropenem,while ≤5.6％of the Enterobacter asburiae strains were resistant to these antimicrobial agents.E.asburiae showed higher resistance rate to polymyxin B than E.cloacae(19.7％vs 3.9％).Overall,≤8.1％of the Enterobacter gergoviae strains were resistant to tigecycline,amikacin,meropenem,or imipenem,while 10.5％of these strains were resistant to polycolistin B.The overall prevalence of carbapenem-resistant Enterobacter was 10.0％over the 7-year period,but showing an upward trend.The resistance profiles of Enterobacter isolates varied with the department from which they were isolated and whether the patient is an adult or a child.The prevalence of carbapenem-resistant E.cloacae was the highest in the E.cloacae isolates from ICU patients.Conclusions The results of the CHINET Antimicrobial Resistance Surveillance Program indicate that the proportion of Enterobacter strains in all clinical isolates fluctuates slightly over the 7-year period from 2015 to 2021.The Enterobacter strains showed increasing resistance to multiple antimicrobial drugs,especially carbapenems over the 7-year period.

Objective To understand the changing distribution and antimicrobial resistance profiles of Proteus,Morganella and Providencia in hospitals across China from January 1,2015 to December 31,2021 in the CHINET Antimicrobial Resistance Surveillance Program.Methods Antimicrobial susceptibility testing was carried out following the unified CHINET protocol.The results were interpreted in accordance with the breakpoints in the 2021 Clinical & Laboratory Standards Institute(CLSI)M100(31 st Edition).Results A total of 32 433 Enterobacterales strains were isolated during the 7-year period,including 24 160 strains of Proteus,6 704 strains of Morganella,and 1 569 strains of Providencia.The overall number of these Enterobacterales isolates increased significantly over the 7-year period.The top 3 specimen source of these strains were urine,lower respiratory tract specimens,and wound secretions.Proteus,Morganella,and Providencia isolates showed lower resistance rates to amikacin,meropenem,cefoxitin,cefepime,cefoperazone-sulbactam,and piperacillin-tazobactam.For most of the antibiotics tested,less than 10％of the Proteus and Morganella strains were resistant,while less than 20％of the Providencia strains were resistant.The prevalence of carbapenem-resistant Enterobacterales(CRE)was 1.4％in Proteus isolates,1.9％in Morganella isolates,and 15.6％in Providencia isolates.Conclusions The overall number of clinical isolates of Proteus,Morganella and Providencia increased significantly in the 7-year period from 2015 to 2021.The prevalence of CRE strains also increased.More attention should be paid to antimicrobial resistance surveillance and rational antibiotic use so as to prevent the emergence and increase of antimicrobial resistance.

Objective To understand the changing distribution and antimicrobial resistance profiles of Klebsiella strains in 52 hospitals across China in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Antimicrobial susceptibility testing was carried out according to the unified CHINET protocol.The susceptibility results were interpreted according to the breakpoints in the Clinical & Laboratory Standards Institute(CLSI)M100 document.Results A total of 241,549 nonduplicate Klebsiella strains were isolated from 2015 to 2021,including Klebsiella pneumoniae(88.0％),Klebsiella aerogenes(5.8％),Klebsiella oxytoca(5.7％),and other Klebsiella species(0.6％).Klebsiella strains were mainly isolated from respiratory tract(48.49±5.32)％.Internal medicine(22.79±3.28)％,surgery(17.98±3.10)％,and ICU(14.03±1.39)％were the top 3 departments where Klebsiella strains were most frequently isolated.K.pneumoniae isolates showed higher resistance rate to most antimicrobial agents compared to other Klebsiella species.Klebsiella isolates maintained low resistance rates to tigecycline and polymyxin B.ESBLs-producing K.pneumoniae and K.oxytoca strains showed higher resistance rates to all the antimicrobial agents tested compared to the corresponding ESBLs-nonproducing strains.The K.pneumoniae and carbapenem-resistant K.pneumoniae(CRKP)strains isolated from ICU patients demonstrated higher resistance rates to majority of the antimicrobial agents tested than the strains isolated from non-ICU patients.The CRKP strains isolated from adult patients had higher resistance rates to most of the antimicrobial agents tested than the corresponding CRKP strains isolated from paediatric patients.Conclusions The prevalence of carbapenem-resistant strains in Klebsiella isolates increased greatly from 2015 to 2021.However,the Klebsiella isolates remained highly susceptible to tigecycline and polymyxin B.Antimicrobial resistance surveillance should still be strengthened for Klebsiella strains.