ObjectiveTo investigate the impact of anticentromere antibody （ACA） on the clinical features and prognosis of patients with primary biliary cholangitis （PBC） by comparing clinical classification， ursodeoxycholic acid （UDCA） response， GLOBE score， and UK-PBC score between ACA-positive PBC patients and ACA-negative PBC patients. MethodsA total of 749 patients who were admitted to Beijing Ditan Hospital， Capital Medical University， from August 2013 to December 2022 and were diagnosed with PBC were enrolled and divided into ACA-positive group with 147 patients and ACA-negative group with 602 patients. According to their conditions on admission， the two groups were compared in terms of the distribution of clinical types， i.e.， chronic progression-type PBC， portal hypertension-type PBC， and standard jaundice/liver failure-type PBC. There were 261 patients with complete data after 1-year follow-up， among whom there were 53 patients with positive ACA and 208 with negative ACA. A statistical analysis was performed， and propensity score matching was performed based on sex and age at a ratio of 1∶2. The two groups were compared in terms of 1-year UDCA response rate， GLOBE score， and UK-PBC score before and after matching. The independent-samples t test or the Mann-Whitney U test was used for comparison of continuous data between two groups， and the chi-square test was used for comparison of categorical data between two groups. ResultsCompared with the ACA-negative group， the ACA-positive group had a significantly higher age （61.28±10.35 years vs 56.74±12.17 years， t=4.164， P<0.001）， a significantly higher proportion of female patients （93.9% vs 77.6%， χ²=20.221， P<0.001）， a significantly higher proportion of patients with portal hypertension （48.3% vs 27.6%， χ²=23.289， P<0.001）， and a significantly lower proportion of patients with jaundice/liver failure （24.5% vs 38.5%， χ²=10.205， P<0.001）. After 1-year follow-up， for the 261 PBC patients with complete data， there was no significant difference in UDCA response rate before propensity score matching between the ACA-positive group and the ACA-negative group （41.5% vs 41.8%， P>0.05）， and there was a significant difference in the proportion of patients with a GLOBE score of >0.3 between the ACA-positive group and the ACA-negative group （92.5% vs 80.3%， χ²=3.935， P=0.047）. There were 53 patients in the ACA-positive group and 106 patients in the ACA-negative group after propensity score matching， and there were no significant differences between the two groups in UDCA response rate， GLOBE score， and UK-PBC score （all P>0.05）. ConclusionACA-positive patients tend to have an older age， with a higher proportion of female patients or patients with portal hypertension， while there is a relatively low proportion of patients with jaundice/liver failure. Positive ACA has no significant impact on UDCA response rate， GLOBE score， and UK-PBC score.

Objective To evaluate the expression differences of C-reactive protein(CRP),procalcitonin(PCT)and cytokines[interferon-γ(IFN-γ),tumor necrosis factor-α(TNF-α),interleukin(IL)-10,IL-6,IL-4,IL-2,IL-17 A,and IFN-γ/IL-10]in human immunodeficiency virus(HIV)infection,tuberculosis(TB)infec-tion and HIV/TB co-infection in order to provide evidence for early clinical diagnosis of HIV/TB co-infection.Methods Medical records and clinical information of 103 patients with HIV(HIV group),42 patients with TB(TB group)and 67 patients with HIV/TB co-infection(HIV/TB group)were collected from January 2021 to September 2022.CRP,PCT and cytokines were detected in all patients,and their expression differ-ences among the three groups were analyzed.Receiver operating characteristic(ROC)curves were drawn and screening ability was evaluated.Results Compared with HIV group and TB group,CRP,PCT,IFN-γ,IL-10,IL-6 levels and IFN-γ/IL-10 in HIV/TB group were increased,with statistical significance(P＜0.001).Bon-ferroni correction results showed that CRP,PCT,IFN-γ,IL-6 levels and IFN-γ/IL-10 were significantly differ-ent between HIV and HIV/TB groups(all P＜0.001).ROC curve analysis showed that the area under the curve of CRP,PCT,IFN-γ,IL-6 and IFN-γ/IL-10 combined detection was 0.826,which was higher than that of single detection.Conclusion CRP,PCT,IFN-γ,IL-6,IFN-γ/IL-10 combined detection can help the early screening of HIV infection and HIV/TB co-infection.

Objective To compare the clinical outcomes of using elastic intramedullary nail and plate to fix fibular frac-ture.Methods The 60 patients with tibiofibular fractures admitted from January 2015 to December 2022 were divided into two groups:intramedullary nail group and plate group,30 cases each,intramedullary nail group was treated with elastic in-tramedullary nail fixation group,plate group was treated with steel plate and screw fixation group.Intramedullary nail group,there were 18 males and 12 females,aged from 22 to 75 years old with an average of(39.4±9.8)years old,including 24 cases of traffic accidents injury,6 cases of falling injury,23 cases of closed fractures,7 cases of open fractures.Steel plate group,there were 15 males and 15 females,aged from 24 to 78 years old with an average of(38.6±10.2)years old.The 22 cases were injured by traffic accident,8 cases were injured by falling.The 24 cases were closed fractures and 6 cases were open fractures.The operation time,intraoperative bleeding,American Orthopedic Foot and Ankle Society(AOFAS)ankle and hind foot scores,clinical healing time of fibula and the incidence of wound complications were compared between the two groups.Re-sults The patients in both groups were followed up for 6 to 21 months,with an average of(14.0±2.8)months.Compared with plate group,intramedullary nail group had shorter operative time,less bleeding,shorter clinical healing time of fibula,and low-er infection rate of incision,and the difference was statistically significant(P＜0.05).There were 2 cases of delayed healing in intramedullary nail group,1 case of nonunion in plate group,and 2 cases of delayed healing in plate group,and there was no statistically significant difference between the two groups(P＞0.05).In the last follow-up,according to the AOFAS scoring standard,the ankle function in intramedullary nail group was excellent in 17 cases,good in 12 cases,fair in 1 case,with an av-erage of(88.33±4.57)points,while in plate group,excellent in 16 cases,good in 10 cases,fair in 4 cases,with an average of(87.00±4.14)points;There was no statistical difference between the two groups(P＞0.05).Conclusion Elastic intramedullary nail has the advantages of short operation time,less intraoperative bleeding,short fracture healing time and less incision com-plications in the treatment of fibular fracture,which is worthy of clinical application.

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.

Objective To investigate the changing distribution and antibiotic resistance profiles of clinical isolates of Staphylococcus in hospitals across China from 2015 to 2021.Methods Antimicrobial susceptibility testing was conducted for the clinical isolates of Staphylococcus according to the unified protocol of CHINET(China Antimicrobial Surveillance Network)using disk diffusion method and commercial automated systems.The CHINET antimicrobial resistance surveillance data from 2015 to 2021 were interpreted according to the 2021 CLSI breakpoints and analyzed using WHONET 5.6.Results During the period from 2015 to 2021,a total of 204,771 nonduplicate strains of Staphylococcus were isolated,including 136,731(66.8％)strains of Staphylococcus aureus and 68,040(33.2％)strains of coagulase-negative Staphylococcus(CNS).The proportions of S.aureus isolates and CNS isolates did not show significant change.S.aureus strains were mainly isolated from respiratory specimens(38.9±5.1)％,wound,pus and secretions(33.6±4.2)％,and blood(11.9±1.5)％.The CNS strains were predominantly isolated from blood(73.6±4.2)％,cerebrospinal fluid(12.1±2.5)％,and pleural effusion and ascites(8.4±2.1)％.S.aureus strains were mainly isolated from the patients in ICU(17.0±7.3)％,outpatient and emergency(11.6±1.7)％,and department of surgery(11.2±0.9)％,whereas CNS strains were primarily isolated from the patients in ICU(32.2±9.7)％,outpatient and emergency(12.8±4.7)％,and department of internal medicine(11.2±1.9)％.The prevalence of methicillin-resistant strains was 32.9％in S.aureus(MRSA)and 74.1％in CNS(MRCNS).Over the 7-year period,the prevalence of MRSA decreased from 42.1％to 29.2％,and the prevalence of MRCNS decreased from 82.1％to 68.2％.MRSA showed higher resistance rates to all the antimicrobial agents tested except trimethoprim-sulfamethoxazole than methicillin-susceptible S.aureus(MSSA).Over the 7-year period,MRSA strains showed decreasing resistance rates to gentamicin,rifampicin,and levofloxacin,MRCNS showed decreasing resistance rates to gentamicin,erythromycin,rifampicin,and trimethoprim-sulfamethoxazole,but increasing resistance rate to levofloxacin.No vancomycin-resistant strains were detected.The prevalence of linezolid-resistant MRCNS increased from 0.2％to 2.3％over the 7-year period.Conclusions Staphylococcus remains the major pathogen among gram-positive bacteria.MRSA and MRCNS were still the principal antibiotic-resistant gram-positive bacteria.No S.aureus isolates were found resistant to vancomycin or linezolid,but linezolid-resistant strains have been detected in MRCNS isolates,which is an issue of concern.

Objective:A SARS-CoV-2 pseudovirus(PsV)system was established for neutralizing antibody evaluation and virus entry inhibitor screening.Methods:Lentiviral vector plasmids psPAX2,pCDH-Luc and SARS-CoV-2 Spike(S)protein expres-sion plasmids were co-transfected,and harvested pseudoviral supernatant was used to infect ACE2-293T cells.Protein content of p24 was determined to reflect titer of PsV,and expression of S protein in PsV was detected by Western blot.Neutralization capacity of an S protein monoclonal antibody was evaluated using original strain,D614G,Gamma,Delta,Omicron PsV.Two reported virus entry inhibitors,chloroquine and carrageenin,were used to detect effect on entry of Omicron PsV.Results:Lentiviral vector successfully incorporated S protein.Western blot results showed that S protein mutated at 665Y showed a different cleavage form(90 kD)than wild-type full-length S protein(180 kD).Titer of PsV packaged by three plasmids system was higher.Ratio of S protein expression plasmid,transfer plasmid and packaging plasmid at 1∶3∶3 was optimum condition for viral packaging.Titer of PsV packaged under this condi-tion was over 20 ng/ml.PsV could effectively infect ACE2-293T cells,and double reporter gene GFP and firefly luciferase were expressed obviously,whose chemiluminescence values reached 106.Monoclonal antibodies of S protein effectively neutralized four types of PsVs,but neutralization of original strain was 10～30 times greater than that of variant PsV.Virus entry inhibitors,chloroquine and ι-carrageenan significantly inhibited entry of Omicron PsV.Conclusion:SARS-CoV-2 PsV infection system we conducted can simu-late entry of SARS-CoV-2 successfully.Effective pharmacodynamic evaluation of neutralizing antibodies and virus entry inhibitors can be performed efficiently by the system,which can provide a technical platform for evaluation of neutralizing antibody of SARS-CoV-2 and screening of virus entry inhibitors,and would benefit R&D of anti-SARS-CoV-2 drugs.