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 analyze the target,signal pathway and potential mechanism of Banxia Baizhu Tianma Decoction in the treatment of epilepsy based on network pharmacology,and to verify it by molecular docking technology and animal experiments.Methods The active ingredients and drug targets of Banxia Baizhu Tianma Decoction were screened by BATMAN and other databases.The targets of epilepsy-related diseases were obtained by GeneCards and other databases,and the intersection targets were taken.Constructing'drug-ingredient-target-disease'network and PPI network to screen the core targets.The core active ingredients were screened according to GO,KEGG functional enrichment analysis and'pathway-target-active ingredient'network.Molecular docking was used to verify the core targets and core active ingredients.In the animal experiment,the rat model of epilepsy was induced by lithium chloride-pilocarpine,and 40 Wistar rats were divided into normal control group,model control group,carbamazepine group and Banxia Baizhu Tianma Decoction group.The seizures were observed by behavior.Nissl staining was used to observe neuronal damage in hippocampus.Immunohistochemistry was used to detect the expression of BAX,BCL-2 and Caspase-3 protein.Results A total of 1072 targets of Banxia Baizhu Tianma Decoction were screened,1046 disease targets of epilepsy were screened,and 220 intersection targets of Banxia Baizhu Tianma Decoction in the treatment of epilepsy were screened.The core targets AKT1,ALB,ACTB,INS and TNF of PPI network were obtained.KEGG pathway mainly involves TNF signaling pathway,IL-17 signaling pathway,cAMP signaling pathway,pathways of neurodegeneration-multiple diseases,serotonergic synapse and Dopaminergic synapse.The core active ingredients with the highest correlation in the'pathway-target-active component'network were Betulin,Ephedrine,Ergotamine and Thymol.Results of molecular docking indicated that the core target had satisfactory affinity with those active ingredients.Animal experiments showed that Banxia Baizhu Tianma Decoction could effectively reduce epileptic seizures in rats,improve hippocampal neuronal damage in rats,significantly reduce the percentage of neuronal apoptosis,significantly down-regulate the expression of pro-apoptotic proteins BAX and Caspase-3,and up-regulate the expression of anti-apoptotic protein BCL-2.Conclusion Banxia Baizhu Tianma Decoction has the characteristics of multi-component,multi-target and multi-pathway in the treatment of epilepsy.Inhibiting neuronal apoptosis and reducing hippocampal neuronal damage may be one of the important mechanisms for its treatment of epilepsy.

Objective To analyze the target,signal pathway and potential mechanism of Banxia Baizhu Tianma Decoction in the treatment of epilepsy based on network pharmacology,and to verify it by molecular docking technology and animal experiments.Methods The active ingredients and drug targets of Banxia Baizhu Tianma Decoction were screened by BATMAN and other databases.The targets of epilepsy-related diseases were obtained by GeneCards and other databases,and the intersection targets were taken.Constructing'drug-ingredient-target-disease'network and PPI network to screen the core targets.The core active ingredients were screened according to GO,KEGG functional enrichment analysis and'pathway-target-active ingredient'network.Molecular docking was used to verify the core targets and core active ingredients.In the animal experiment,the rat model of epilepsy was induced by lithium chloride-pilocarpine,and 40 Wistar rats were divided into normal control group,model control group,carbamazepine group and Banxia Baizhu Tianma Decoction group.The seizures were observed by behavior.Nissl staining was used to observe neuronal damage in hippocampus.Immunohistochemistry was used to detect the expression of BAX,BCL-2 and Caspase-3 protein.Results A total of 1072 targets of Banxia Baizhu Tianma Decoction were screened,1046 disease targets of epilepsy were screened,and 220 intersection targets of Banxia Baizhu Tianma Decoction in the treatment of epilepsy were screened.The core targets AKT1,ALB,ACTB,INS and TNF of PPI network were obtained.KEGG pathway mainly involves TNF signaling pathway,IL-17 signaling pathway,cAMP signaling pathway,pathways of neurodegeneration-multiple diseases,serotonergic synapse and Dopaminergic synapse.The core active ingredients with the highest correlation in the'pathway-target-active component'network were Betulin,Ephedrine,Ergotamine and Thymol.Results of molecular docking indicated that the core target had satisfactory affinity with those active ingredients.Animal experiments showed that Banxia Baizhu Tianma Decoction could effectively reduce epileptic seizures in rats,improve hippocampal neuronal damage in rats,significantly reduce the percentage of neuronal apoptosis,significantly down-regulate the expression of pro-apoptotic proteins BAX and Caspase-3,and up-regulate the expression of anti-apoptotic protein BCL-2.Conclusion Banxia Baizhu Tianma Decoction has the characteristics of multi-component,multi-target and multi-pathway in the treatment of epilepsy.Inhibiting neuronal apoptosis and reducing hippocampal neuronal damage may be one of the important mechanisms for its treatment of epilepsy.

Objective To analyze the risk factors for meconium-stained amniotic fluid(MSAF)in preterm infants and the clinical outcome and prognosis of preterm infants.Methods Preterm infants with gestational age＜37 weeks delivered in Zhangjiajie People's Hospital from January 2022 to December 2023 were used as the study subjects,31 cases with MSAF were in MSAF group,and 31 cases of preterm infants hospitalized during the same period without MSAF were randomly paired in the ratio of 1∶1 to select with gestational age-body mass matching as non-MSAF group.Retrospective collection and analysis of pregnancy and perinatal conditions of mothers of preterm infants in two groups,comparing the differences of related factors between two groups of children;Logistic regression analysis of risk factors related to MSAF in preterm infants;comparing the complications and clinical outcomes of preterm infants in two groups.Results A total of 387 preterm infants with gestational age＜37 weeks were collected during the study period,including 31 preterm infants with comorbid MSAF,and the prevalence of MSAF in preterm infants was 8.0％.MSAF group had a higher incidence of advanced maternal age,premature rupture of membranes＞18 hours,antepartum fever,and cholestasis during pregnancy than non-MSAF group.Logistic regression analysis suggested that combined cholestasis during pregnancy and white blood cell count ≥ 30× 109/L within 6 hours after birth increased the incidence of MSAF in preterm infants.There was no statistically significant difference in the results of postnatal umbilical artery blood gas analysis between two groups of preterm infants.The proportion of leukocyte count ≥30×109/L,ultrasensitive C-reactive protein＞0.8 mg/L,and interleukin 6＞6 pg/L in MSAF group was higher than that of non-MSAF group in the 6 hours after birth.MSAF group had a higher incidence of intrauterine infectious pneumonia,feeding intolerance,and necrotizing small bowel colitis in neonates than non-MSAF group.Conclusion Advanced maternal age,intrauterine infections,and combined intrahepatic cholestasis during pregnancy may be the major risk factors for MSAF in preterm infants.MSAF preterm infants have a higher prevalence of intrauterine infectious pneumonitis,feeding intolerance,and necrotizing small bowel colitis in newborns,as well as longer hospital stays.

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 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.

Porcine hemagglutinating encephalomyelitis virus(PHEV)is one of the coronaviruses susceptible to swine populations.The non-structural protein 2(NS2)encoded by its genome is fre-quently deleted during the epidemic transmission of the virus,but its biological significance re-mains unclear.In order to explore the structure and function of the NS2 protein,this study utilized platforms such as ProtParam,TMHMM,NetPhos3.1,and ExPASy to analyze its physicochemical properties,spatial structure,genetic evolution,and post-translational modification characteristics.Meanwhile,the NS2 protein was expressed in eukaryotes and transcriptome sequencing was per-formed to clarify the biological processes it participates in.The results showed that the NS2 protein consists of 233 amino acids,with a molecular weight of 26.735 kDa,and a half-life of approximately 30 hours in mammals.It includes 13 phosphorylation sites,2 N-glycosylation sites,and 1 O-glyco-sylation site,with no signal peptide and strong hydrophilicity.The a-helix accounts for the highest proportion in NS2(43.78％),followed by random coils(36.05％).The homology of the NS2 pro-tein between the epidemic strains PHEV-CC14 and PHEV-JL/2008 in Northeast China is 99.57％.The NS2 protein is widely involved in the regulation of nerve-related functions,such as axon guid-ance and synaptic development.This study preliminarily clarified the biological function of the NS2 protein,providing a new perspective for understanding the pathogenic mechanism of PHEV.