Hepatitis B virus （HBV） exclusively infects liver parenchymal cells and forms covalently closed circular DNA （cccDNA） within their nuclei. HBV cccDNA serves as the essential template for viral gene transcription， the sole source of progeny virus production， and the key driver of viral antigen expression， and it is the molecular basis for the persistence of HBV infection. Therefore， elimination and/or functional silencing of cccDNA is the key to eradicate chronic HBV infection. This article discusses the critical scientific issues that need to be solved during elimination of the harm of HBV infection from the perspectives of the synthesis， transcription， and clearance of cccDNA， as well as the impact of nonparenchymal cells on cccDNA， in order to provide a reference for eradicating HBV infection in the future.

Objective To investigate the distribution and antimicrobial resistance profiles of common pathogens isolated from cerebrospinal fluid(CSF)in CHINET program from 2015 to 2021.Methods The bacterial strains isolated from CSF were identified in accordance with clinical microbiology practice standards.Antimicrobial susceptibility test was conducted using Kirby-Bauer method and automated systems per the unified CHINET protocol.Results A total of 14 014 bacterial strains were isolated from CSF samples from 2015 to 2021,including the strains isolated from inpatients(95.3％)and from outpatient and emergency care patients(4.7％).Overall,19.6％of the isolates were from children and 80.4％were from adults.Gram-positive and Gram-negative bacteria accounted for 68.0％and 32.0％,respectively.Coagulase negative Staphylococcus accounted for 73.0％of the total Gram-positive bacterial isolates.The prevalence of MRSA was 38.2％in children and 45.6％in adults.The prevalence of MRCNS was 67.6％in adults and 69.5％in children.A small number of vancomycin-resistant Enterococcus faecium(2.2％)and linezolid-resistant Enterococcus faecalis(3.1％)were isolated from adult patients.The resistance rates of Escherichia coli and Klebsiella pneumoniae to ceftriaxone were 52.2％and 76.4％in children,70.5％and 63.5％in adults.The prevalence of carbapenem-resistant E.coli and K.pneumoniae(CRKP)was 1.3％and 47.7％in children,6.4％and 47.9％in adults.The prevalence of carbapenem-resistant Acinetobacter baumannii(CRAB)and Pseudomonas aeruginosa(CRPA)was 74.0％and 37.1％in children,81.7％and 39.9％in adults.Conclusions The data derived from antimicrobial resistance surveillance are crucial for clinicians to make evidence-based decisions regarding antibiotic therapy.Attention should be paid to the Gram-negative bacteria,especially CRKP and CRAB in central nervous system(CNS)infections.Ongoing antimicrobial resistance surveillance is helpful for optimizing antibiotic use in CNS infections.

Objective To investigate the antimicrobial resistance of clinical isolates from elderly patients(≥65 years)in major medical institutions across China.Methods Bacterial strains were isolated from elderly patients in 52 hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program during the period from 2015 to 2021.Antimicrobial susceptibility test was carried out by disk diffusion method and automated systems according to the same CHINET protocol.The data were interpreted in accordance with the breakpoints recommended by the Clinical and Laboratory Standards Institute(CLSI)in 2021.Results A total of 514 715 nonduplicate clinical isolates were collected from elderly patients in 52 hospitals from January 1,2015 to December 31,2021.The number of isolates accounted for 34.3％of the total number of clinical isolates from all patients.Overall,21.8％of the 514 715 strains were gram-positive bacteria,and 78.2％were gram-negative bacteria.Majority(90.9％)of the strains were isolated from inpatients.About 42.9％of the strains were isolated from respiratory specimens,and 22.9％were isolated from urine.More than half(60.7％)of the strains were isolated from male patients,and 39.3％isolated from females.About 51.1％of the strains were isolated from patients aged 65-＜75 years.The prevalence of methicillin-resistant strains(MRSA)was 38.8％in 32 190 strains of Staphylococcus aureus.No vancomycin-or linezolid-resistant strains were found.The resistance rate of E.faecalis to most antibiotics was significantly lower than that of Enterococcus faecium,but a few vancomycin-resistant strains(0.2％,1.5％)and linezolid-resistant strains(3.4％,0.3％)were found in E.faecalis and E.faecium.The prevalence of penicillin-susceptible S.pneumoniae(PSSP),penicillin-intermediate S.pneumoniae(PISP),and penicillin-resistant S.pneumoniae(PRSP)was 94.3％,4.0％,and 1.7％in nonmeningitis S.pneumoniae isolates.The resistance rates of Klebsiella spp.(Klebsiella pneumoniae 93.2％)to imipenem and meropenem were 20.9％and 22.3％,respectively.Other Enterobacterales species were highly sensitive to carbapenem antibiotics.Only 1.7％-7.8％of other Enterobacterales strains were resistant to carbapenems.The resistance rates of Acinetobacter spp.(Acinetobacter baumannii 90.6％)to imipenem and meropenem were 68.4％and 70.6％respectively,while 28.5％and 24.3％of P.aeruginosa strains were resistant to imipenem and meropenem,respectively.Conclusions The number of clinical isolates from elderly patients is increasing year by year,especially in the 65-＜75 age group.Respiratory tract isolates were more prevalent in male elderly patients,and urinary tract isolates were more prevalent in female elderly patients.Klebsiella isolates were increasingly resistant to multiple antimicrobial agents,especially carbapenems.Antimicrobial resistance surveillance is helpful for accurate empirical antimicrobial therapy in elderly patients.

BACKGROUND:When exercising in a cold environment,the body's inflammatory response is affected by both low temperature and exercise intervention,and its impact and mechanism remain to be explored.OBJECTIVE:To explore the effects and mechanisms of cold water swimming on inflammatory response of rats based on transcriptome sequencing technology.METHODS:40 male SD rats were randomly divided into room temperature control group,room temperature swimming group,cold water control group,and cold water swimming group,with 10 rats in each group.The room temperature control group had no intervention and was free to eat.The room temperature swimming group received swimming at 30 min/time,6 times/week,for 5 weeks;the water temperature was(28±2)℃,and the water depth was 35 cm.In the cold water control group,the rats were placed in a water tank with a depth of 3 cm;the water temperature was(18±2)℃,and they were free to move.The cold water swimming group received swimming at 30 min/time,6 times/week,for 5 weeks;the water temperature was(18±2)℃,and the water depth was 35 cm.Enzyme-linked immunosorbent assay was used to detect the levels of serum interleukin-6,tumor necrosis factor-α,and high-sensitivity C-reactive protein.Based on the transcriptome sequencing results,differentially expressed genes were screened to draw Venn diagrams and heat maps,and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis were performed.The protein-protein interaction network was used to screen core genes.RT-qPCR was used to detect the mRNA expression of IRF7,OAS2,and OASL in rat spleen tissue.RESULTS AND CONCLUSION:(1)The ELISA results showed that compared with the room temperature control group,the levels of various inflammatory indicators in the room temperature swimming group and the cold water swimming group were significantly increased(P＜0.05),and there was no significant difference in the cold water control group.Compared with the room temperature swimming group,there was no significant difference in the expression of inflammatory indicators in the cold water swimming group.Compared with the cold water control group,the expressions of interleukin-6 and tumor necrosis factor-α in the cold water swimming group showed an upward trend,and high-sensitivity C-reactive protein increased significantly(P＜0.05).(2)Transcriptome analysis:Venn diagram showed that there were 39 differentially expressed genes affected by the dual factors of temperature and exercise intervention.Cluster heat map analysis results showed that the overall gene expression trends of the room temperature swimming group and the cold water swimming group were similar,and the cold water control group showed an opposite trend.Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis results showed that differentially expressed genes were enriched in the immune system,locomotion,nucleic acid-binding transcription factor activity,NOD-like receptor signaling pathways and other pathways.The number of genes enriched in the NOD-like receptor signaling pathway was relatively large,and the q value was small,which may be a key pathway.The protein-protein interaction network screened out IRF7,OAS2,OASL,IFIT2,IFIT3 and other core genes.(3)RT-qPCR verification results showed that compared with the room temperature control group,the expressions of IRF7,OAS2 and OASL were significantly increased in the room temperature swimming group and the cold water swimming group(P＜0.01),and there was no significant difference in the cold water control group.Compared with the cold water control group,the expression of each gene was significantly increased in the cold water swimming group(P＜0.01).(4)It is concluded that cold water swimming can promote inflammatory response,and its mechanism may be regulated through the NOD-like receptor signaling pathway.

Diabetes mellitus is the third most prevalent disease worldwide,following cardiovascular diseases and cancer.There is no obvious symptom in the early stage of diabetes mellitus.However,in the middle and late stages,diabetes mellitus may lead to severe clinical complications such as diabetic cardiomyopathy,kidney disease,retinopathy,or neuropathy,the primary causes for diabetes-related deaths.Therefore,the early diagnosis and treatment of diabetes mellitus are of practical significance.Compared with traditional diagnostic methods including fasting blood-glucose and oral glucose tolerance tests,the measurement of glycated hemoglobin serves as a gold standard for evaluating long-term blood glucose control,due to the relative stability of glycated hemoglobin under a period of dietary and daily practice.Ear-ly treatment of diabetes mellitus may significantly improve the prognosis of patients and enhance the overall therapeutic out-come.Diet control,physical exercise,medication,as well as psychological and social supports are critical for the treat-ment of diabetes mellitus.To date,the therapeutic methods for diabetes mellitus have been constantly enriching,along with promoted drug design and development.Some emerging technologies,such as therapies using antibodies or stem cells,have been applied to treat diabetes mellitus.Hereby the latest progress in the prevention and treatment of diabetes mellitus was comprehensively reviewed,and the application of antibodies was discussed,which may provide insights into the research and development of antibody drugs for chronic human diseases including diabetes mellitus.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective To explore the molecular mechanism of plasmalemmal vesicle-associated protein(PLVAP)regulating high glucose(HG)induced endocytosis dysfunction in human liver sinusoidal endothelial cells(HLSECs)through Kelch-like epichlorohydrin ECH-associated protein 1(Keap1)/nuclear factor erythroid 2-related factor 2(Nrf2)/Maf protein.Methods HLSECs were cultured in vitro and divided into normal control(NC)group,high glucose(HG)group,PLVAP overexpression recombinant vector(LV-PLVAP)group,lentivirus empty vector(LV-CON)group,HG+LV-PLVAP+Nrf2 inhibitor(ML385)group,HG+LV-PLVAP+Maf inhibitor(Mafenide)group,HG+LV-CON+ML385 group and HG+LV-CON+Mafenide group.Cell activity was detected by CCK-8 assay.The transfection efficiency of LV-PLVAP was observed by fluorescence microscopy.The fluorescence expression of PLVAP and Nrf2 was detected by immunofluorescence.RT-PCR and western blot were used to detect the mRNA and protein expression of PLVAP,Keap1,Nrf2,and Maf,Caveolin-1(CAV-1).Results A lot of green fluorescence appeared in LV-PLVAP and LV-CON groups,however,no green fluorescence was shown in NC group.Immunofluorescence results showed that PLVAP was expressed in cell membrane;Nrf2 was expressed in cytoplasm,and in HG group,Nrf2 was expressed in nucleus.Compared with NC group,the expression of PLVAP,Keap1 mRNA and protein decreased in HG group(P<0.05 or P<0.01),while the expression of Nrf2,Maf and CAV-1 mRNA and protein increased in HG group(P<0.01).Compared with HG group,the expression of PLVAP,Keap1,Nrf2 mRNA and protein increased in HG+LV-PLVAP group(P<0.01),while the expression of Maf,CAV-1 mRNA and protein decreased in HG+LV-PLVAP group(P<0.01).Compared with HG+LV-PLVAP group,the expression of CAV-1 mRNA and protein increased in HG+LV-PLVAP+ML385 and HG+LV-PLVAP+Mafenide groups(P<0.05 or P<0.01).Conclusions PLVAP regulates the expression of CAV-1 through the Keap1/Nrf2/Maf pathway and then regulates HG induced endocytosis dys-function in HLSECs.Over expression of PLVAP alleviates this pathological reaction.

Objective To examine the changing prevalence and antimicrobial resistance profiles of Burkholderia cepacia in 52 hospitals across China from 2015 to 2021.Methods A total of 9 261 strains of B.cepacia were collected from 52 hospitals between January 1,2015 and December 31,2021.Antimicrobial susceptibility of the strains was tested using Kirby-Bauer method or automated antimicrobial susceptibility testing systems according to a unified protocol.The results were interpreted according to the breakpoints released in the Clinical & Laboratory Standards Institute(CLSI)guidelines(2023 edition).Results A total of 9 261 strains of B.cepacia were isolated from all age groups,especially elderly patients.The proportion was 11.1％(1 032 strains)in children,significantly lower than the proportion in adults.About half(46.5％,4 310/9 261)of the strains were isolated from patients at least 60 years old and 42.3％(3 919/9 261)of the strains were isolated from young adults.Most isolates(71.1％)were isolated from sputum and respiratory secretions,followed by urine(10.7％)and blood samples(8.1％).B.cepacia isolates were highly susceptible to the five antimicrobial agents recommended in the CLSI M100 document(33rd edition,2023).B.cepacia isolates showed relatively higher resistance rates to meropenem and levofloxacin.However,the resistance rates to ceftazidime,trimethoprim-sulfamethoxazole,and minocycline remained below 8.1％.The percentage of B.cepacia strains resistant to levofloxacin was the highest compared to other antibiotics in any of the three age groups(from 12.4％in the patients＜18 years old to 20.6％in the patients aged 60 years or older).Conclusions B.cepacia is one of the clinically important non-fermenting gram-negative bacteria.Accurate and timely reporting of antimicrobial susceptibility test results and ongoing antimicrobial resistance surveillance are helpful for rational prescription of antimicrobial agents and proper prevention and control of nosocomial infections.

Objective To summarize the changing prevalence of carbapenem resistance in Enterobacterales based on the data of CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021 for improving antimicrobial treatment in clinical practice.Methods Antimicrobial susceptibility testing was performed using a commercial automated susceptibility testing system according to the unified CHINET protocol.The results were interpreted according to the breakpoints of the Clinical & Laboratory Standards Institute(CLSI)M100 31st ed in 2021.Results Over the seven-year period(2015-2021),the overall prevalence of carbapenem-resistant Enterobacterales(CRE)was 9.43％(62 342/661 235).The prevalence of CRE strains in Klebsiella pneumoniae,Citrobacter freundii,and Enterobacter cloacae was 22.38％,9.73％,and 8.47％,respectively.The prevalence of CRE strains in Escherichia coli was 1.99％.A few CRE strains were also identified in Salmonella and Shigella.The CRE strains were mainly isolated from respiratory specimens(44.23±2.80)％,followed by blood(20.88±3.40)％and urine(18.40±3.45)％.Intensive care units(ICUs)were the major source of the CRE strains(27.43±5.20)％.CRE strains were resistant to all the β-lactam antibiotics tested and most non-β-lactam antimicrobial agents.The CRE strains were relatively susceptible to tigecycline and polymyxins with low resistance rates.Conclusions The prevalence of CRE strains was increasing from 2015 to 2021.CRE strains were highly resistant to most of the antibacterial drugs used in clinical practice.Clinicians should prescribe antimicrobial agents rationally.Hospitals should strengthen antibiotic stewardship in key clinical settings such as ICUs,and take effective infection control measures to curb CRE outbreak and epidemic in hospitals.

Objective To characterize the changing species distribution and antibiotic resistance profiles of respiratory isolates in hospitals participating in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods Commercial automated antimicrobial susceptibility testing systems and disk diffusion method were used to test the susceptibility of respiratory bacterial isolates to antimicrobial agents following the standardized technical protocol established by the CHINET program.Results A total of 589 746 respiratory isolates were collected from 2015 to 2021.Overall,82.6％of the isolates were Gram-negative bacteria and 17.4％were Gram-positive bacteria.The bacterial isolates from outpatients and inpatients accounted for(6.0±0.9)％and(94.0±0.1)％,respectively.The top microorganisms were Klebsiella spp.,Acinetobacter spp.,Pseudomonas aeruginosa,Staphylococcus aureus,Haemophilus spp.,Stenotrophomonas maltophilia,Escherichia coli,and Streptococcus pneumoniae.Each microorganism was isolated from significantly more males than from females(P＜0.05).The overall prevalence of methicillin-resistant S.aureus(MRSA)was 39.9％.The prevalence of penicillin-resistant S.pneumoniae was 1.4％.The prevalence of extended-spectrum β-lactamase(ESBL)-producing E.coli and K.pneumoniae was 67.8％and 41.3％,respectively.The overall prevalence of carbapenem-resistant E.coli,K.pneumoniae,Enterobacter cloacae,Pseudomonas aeruginosa,and Acinetobacter baumannii was 3.7％,20.8％,9.4％,29.8％,and 73.3％,respectively.The prevalence of β-lactamase was 96.1％in Moraxella catarrhalis and 60.0％in Haemophilus influenzae.The H.influenzae isolates from children(＜18 years)showed significantly higher resistance rates to β-lactam antibiotics than the isolates from adults(P＜0.05).Conclusions Gram-negative bacteria are still predominant in respiratory isolates associated with serious antibiotic resistance.Antimicrobial resistance surveillance should be strengthened in clinical practice to support accurate etiological diagnosis and appropriate antimicrobial therapy based on antimicrobial susceptibility testing results.