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.

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.

Objective:To explore the relapse-related genes and their clinicopathological connections of diffuse large B cell lymphoma (DLBCL).Methods:Targeted panel sequencing was conducted on 32 eligible DLBCL samples; the patients were diagnosed, treated, and went into complete remission at the First Affiliated Hospital of Nanjing Medical University from January 2015 to December 2019, including 14 cases with recurrence (relapsed group) and 18 cases with long-term complete remission of over five years (remission group). Clinical and pathological data were further reviewed. Fisher′s exact test was employed to compare the differences in clinicopathological characteristics and mutation patterns between the two groups.Results:Among the 32 patients, there were 18 males and 14 females, with a male to female ratio of 1.3∶1.0 and a median age of 53 (45.5, 67.0) years. In the relapsed group, PIM1 (11/14), KMT2D (7/14), PRDM1 (6/14), MYD88 (6/14), DTX1 (6/14) emerged as the most frequently mutated genes. In the remission group, while recurrent PIM1, KMT2D and MYD88 mutations were also observed, the TP53 gene exhibited the highest mutation frequency (6/18). Compared to the remission group, relapsed group showed elevated mutation frequencies of PIM1 ( P=0.013) and FAT4 ( P=0.010), alongside a reduced incidence of TP53 mutations. In all 32 patients, DLBCL with CD79B, CCND3, DTX1, KMT2D and PRDM1 mutations demonstrated a propensity towards advanced clinicopathologic stage. Conclusions:Relapsed DLBCL has distinctive clinicopathological and genetic features. PIM1 and FAT4 may be served as potential biomarkers for screening relapsed DLBCL-NOS and as targets for novel therapeutic strategies.

Aim To investigate the intestinal protection and possible mechanism of magnolol(MG)in newborn rats with necrotizing enterocolitis(NEC).Methods The rats were randomly divided into control group(Ctrl group),model group(NEC group)and treatment group(MG group).The NEC model was induced by hypoxia,cold stimulation,deep formula milk and LPS intragastric administration in 7-day-old rats for four days.They were killed after five days of treatment with MG(20 mg·kg-1).HE staining was used to observe the intestinal pathological injury.Western blot was used to detect the expressions of IL-1 β,TNF-α,NL-RP3,ASC,caspase-1 and tight junction protein in the distal ileum of rats.Colon contents were collected for 16S rDNA sequencing to understand the gut microbio-ta.Results MG improved the body mass and intesti-nal injury of NEC neonatal rats.The expressions of in-testinal IL-1β,TNF-α,NLRP3,ASC and caspase-1 proteins were down-regulated,and the expressions of Claudin,Occludin and ZO-1 proteins were up-regula-ted.16S rDNA showed that MG increased the diversity of intestinal flora,and at the phylum level,MG in-creased the abundance of firmicutes and bacteroides in NEC model,and decreased the abundance of pro-teobacteria.At the genus level,MG treatment in-creased the abundance of Lactobacillus,unclassified_Muribaculaceae,Racteroides,but decreased the abun-dance of Escherichia_Shigella,Rodentibacter and Fuso-bacterium.Conclusion MG intervention can protect the intestinal tract of NEC rats by potentially improving barrier function,and regulating the intestinal microbiota through the NLRP3/ASC/caspase-1 signaling pathway.

Aim To investigate the intestinal protection and possible mechanism of magnolol(MG)in newborn rats with necrotizing enterocolitis(NEC).Methods The rats were randomly divided into control group(Ctrl group),model group(NEC group)and treatment group(MG group).The NEC model was induced by hypoxia,cold stimulation,deep formula milk and LPS intragastric administration in 7-day-old rats for four days.They were killed after five days of treatment with MG(20 mg·kg-1).HE staining was used to observe the intestinal pathological injury.Western blot was used to detect the expressions of IL-1 β,TNF-α,NL-RP3,ASC,caspase-1 and tight junction protein in the distal ileum of rats.Colon contents were collected for 16S rDNA sequencing to understand the gut microbio-ta.Results MG improved the body mass and intesti-nal injury of NEC neonatal rats.The expressions of in-testinal IL-1β,TNF-α,NLRP3,ASC and caspase-1 proteins were down-regulated,and the expressions of Claudin,Occludin and ZO-1 proteins were up-regula-ted.16S rDNA showed that MG increased the diversity of intestinal flora,and at the phylum level,MG in-creased the abundance of firmicutes and bacteroides in NEC model,and decreased the abundance of pro-teobacteria.At the genus level,MG treatment in-creased the abundance of Lactobacillus,unclassified_Muribaculaceae,Racteroides,but decreased the abun-dance of Escherichia_Shigella,Rodentibacter and Fuso-bacterium.Conclusion MG intervention can protect the intestinal tract of NEC rats by potentially improving barrier function,and regulating the intestinal microbiota through the NLRP3/ASC/caspase-1 signaling pathway.

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 investigate the the differential expression of EIF5A2 in intrahepatic cholangiocarcinoma cell lines RBE,HCCC9810,and HUCCT1,and its effects on HCCC9810 cell migration and invasion,epithelial mesenchymal transition,and PI3K/AKT signaling pathway.Methods:The differential expression of EIF5A2 in RBE,HCCC9810,and HUCCT1 cell lines was detected using WB method.The HCCC9810 cell line,with the highest expression of EIF5A2,was selected for this experiment.The expression of EIF5A2 in HCCC9810 cell line was silenced by transient transfection of small interfering RNA.The best silencing effect of small interfering RNA was screened by WB.Scratch assay and Tran-swell migration invasion assay were used to detect the effect of silencing EIF5A2 on the migration and invasion ability of HCCC9810 cells.WB was used to detect the effect of silencing EIF5A2 on PI3K/AKT signaling pathway and epithelial mesenchymal transition in HCCC9810 cells.Results:The WB results showed that EIF5A2 had the highest expression in the HCCC9810 cell line,and siRNA1 had the best silencing effect on EIF5A2 in the HCCC9810 cell line.Scratch assay and Transwell migration invasion assay results showed that silencing EIF5A2 in the HCCC9810 cell line resulted in a decrease in cell invasion and metastasis ability(P＜0.05).At the same time,the expression of p-PI3K and p-AKT in the PI3K/AKT signaling pathway was significantly decreased(P＜0.05),while the epithelial cell marker E-cadherin expression increased(P＜0.05)and the stromal cell marker N-cadherin expression decreased(P＜0.05).Conclusion:EIF5A2 may promote epi-thelial mesenchymal transition and enhance the migration and invasion ability of intrahepatic cholangiocarcinoma cells through the PI3K/AKT signaling pathway.

Objective To investigate the distribution and antimicrobial resistance profiles of clinically isolated Haemophilus influenzae and Moraxella catarrhalis in hospitals across China from 2015 to 2021,and provide evidence for rational use of antimicrobial agents.Methods Data of H.influenzae and M.catarrhalis strains isolated from 2015 to 2021 in CHINET program were collected for analysis,and antimicrobial susceptibility testing was performed by disc diffusion method or automated systems according to the uniform protocol of CHINET.The results were interpreted according to the CLSI breakpoints in 2022.Beta-lactamases was detected by using nitrocefin disk.Results From 2015 to 2021,a total of 43 642 strains of Haemophilus species were isolated,accounting for 2.91％of the total clinical isolates and 4.07％of Gram-negative bacteria in CHINET program.Among the 40 437 strains of H.influenzae,66.89％were isolated from children and 33.11％were isolated from adults.More than 90％of the H.influenzae strains were isolated from respiratory tract specimens.The prevalence of β-lactamase was 53.79％in H.influenzae strains.The H.influenzae strains isolated from children showed higher resistance rate than the strains isolated from adults.Overall,779 strains of H.influenzae did not produce β-lactamase but were resistant to ampicillin(BLNAR).Beta-lactamase-producing strains showed significantly higher resistance rates to these antimicrobial agents than the β-lactamase-nonproducing strains.Of the 16 191 M.catarrhalis strains,80.06％were isolated from children and 19.94％isolated from adults.M.catarrhalis strains were mostly susceptible to both amoxicillin-clavulanic acid and cefuroxime,evidenced by resistance rate lower than 2.0％.Conclusions The emergence of antibiotic-resistant H.influenzae due to β-lactamase production poses a challenge for clinical anti-infective treatment.Therefore,it is very important to implement antibiotic resistance surveillance for H.influenzae and guide rational antibiotic use.All local clinical microbiology laboratories should actively improve antibiotic susceptibility testing and strengthen antibiotic resistance surveillance for H.influenzae.