Objective To understand the changing composition and antibiotic resistance of bacterial species in the clinical isolates from outpatient and emergency department(hereinafter referred to as outpatients)and inpatient children over time in various hospitals,and to provide laboratory evidence for rational antibiotic use.Methods The data on clinically isolated pathogenic bacteria and antimicrobial susceptibility of isolates from outpatients and inpatient children in the CHINET program from 2015 to 2021 were collected and analyzed.Results A total of 278 471 isolates were isolated from pediatric patients in the CHINET program from 2015 to 2021.About 17.1％of the strains were isolated from outpatients,primarily group A β-hemolytic Streptococcus,Escherichia coli,and Staphylococcus aureus.Most of the strains(82.9％)were isolated from inpatients,mainly SS.aureus,E.coli,and H.influenzae.The prevalence of methicillin-resistant S.aureus(MRSA)in outpatients(24.5％)was lower than that in inpatient children(31.5％).The MRSA isolates from outpatients showed lower resistance rates to the antibiotics tested than the strains isolated from inpatient children.The prevalence of vancomycin-resistant Enterococcus faecalis or E.faecium and penicillin-resistant S.pneumoniae was low in either outpatients or inpatient children.S.pneumoniae,β-hemolytic Streptococcus and S.viridans showed high resistance rates to erythromycin.The prevalence of erythromycin-resistant group A β-hemolytic Streptococcus was higher in outpatients than that in inpatient children.The prevalence of β-lactamase-producing H.influenzae showed an overall upward trend in children,but lower in outpatients(45.1％)than in inpatient children(59.4％).The prevalence of carbapenem-resistant Klebsiella pneumoniae(CRKpn),carbapenem-resistant Pseudomonas aeruginosa(CRPae)and carbapenem-resistant Acinetobacter baumannii(CRAba)was 14％,11.7％,47.8％in outpatients,but 24.2％,20.6％,and 52.8％in inpatient children,respectively.The prevalence of multidrug-resistant E.coli,K.pneumoniae,Proteus mirabilis,P.aeruginosa and A.baumannii strains was lower in outpatients than in inpatient children.The prevalence of fluoroquinolone-resistant E.coli,ESBLs-producing K.pneumoniae,ESBLs-producing P.mirabilis,carbapenem-resistant E.coli(CREco),CRKpn,and CRPae was lower in children in outpatients than in inpatient children,but the prevalence of CRAba in 2021 was higher than in inpatient children.Conclusions The distribution of clinical isolates from children is different between outpatients and inpatients.The prevalence of MRSA,ESBL,and CRO was higher in inpatient children than in outpatients.Antibiotics should be used rationally in clinical practice based on etiological diagnosis and antimicrobial susceptibility test results.Ongoing antimicrobial resistance surveillance and prevention and control of hospital infections are crucial to curbing bacterial resistance.

Objective To investigate the changing antibiotic resistance profiles of E.coli isolated from patients in the 52 hospitals participating in the CHINET program from 2015 to 2021.Methods Antimicrobial susceptibility was tested for clinical isolates of E.coli according to the unified protocol of CHINET program.WHONET 5.6 and SPSS 20.0 software were used for data analysis.Results Atotal of 289 760 nonduplicate clinical strains ofE.coli were isolated from 2015 to 2021,mainly from urine samples(44.7±3.2)％.The proportion of E.coli strains isolated from urine samples was higher in females than in males(59.0％vs 29.5％).The proportion of E.coli strains isolated from respiratory tract and cerebrospinal fluid samples was significantly higher in children than in adults(16.7％vs 7.8％,0.8％vs 0.1％,both P＜0.05).The isolates from internal medicine department accounted for the largest proportion(28.9±2.8)％with an increasing trend over years.Overall,the prevalence of ESBLs-producing E.coli and carbapenem resistant E.coli(CREco)was 55.9％and 1.8％,respectively during the 7-year period.The prevalence of ESBLs-producing E.coli was the highest in tertiary hospitals each year from 2015 to 2021 compared to secondary hospitals.The prevalence of CREco was higher in children's hospitals compared to secondary and tertiary hospitals each year from 2015 to 2021.The prevalence of ESBLs-producing E.coli in tertiary hospitals and children's hospitals and the prevalence of CREco in children's hospitals showed a decreasing trend over the 7-year period.The prevalence of CREco in secondary and tertiary hospitals increased slowly.Antibiotic resistance rates changed slowly from 2015 to 2021.Carbapenem drugs(imipenem,meropenem)were the most active drugs amongβ-lactams against E.coli(resistance rate≤2.1％).The resistance rates of E.coli to β-lactam/β-lactam inhibitor combinations(piperacillin-tazobactam,cefoperazone-sulbactam),aminoglycosides(amikacin),nitrofurantoin and fosfomycin(for urinary isolates only)were all less than 10％.The resistance rate of E.coli strains to antibiotics varied with the level of hospitals and the departments where the strains were isolated,especially for cefazolin and ciprofloxacin,to which the resistance rate of E.coli strains from children in non-ICU departments was significantly lower than that of the strains isolated from other departments(P＜0.05).The E.coli isolates from ICU showed higher resistance rate to most antimicrobial agents tested(excluding tigecycline)than the strains isolated from other departments.The E.coli strains isolated from tertiary hospitals showed higher resistance rates to the antimicrobial agents tested(excluding tigecycline,polymyxin B,cefepime and carbapenems)than the strains from secondary hospitals and children's hospitals.Conclusions E.coli is an important pathogen causing clinical infection.More than half of the clinical isolates produced ESBL.The prevalence of CREco is increasing in secondary and tertiary hospitals over the 7-year period even though the overall prevalence is still low.This is an issue of concern.

Objective To understand the changing composition and antibiotic resistance of bacterial species in the clinical isolates from outpatient and emergency department(hereinafter referred to as outpatients)and inpatient children over time in various hospitals,and to provide laboratory evidence for rational antibiotic use.Methods The data on clinically isolated pathogenic bacteria and antimicrobial susceptibility of isolates from outpatients and inpatient children in the CHINET program from 2015 to 2021 were collected and analyzed.Results A total of 278 471 isolates were isolated from pediatric patients in the CHINET program from 2015 to 2021.About 17.1％of the strains were isolated from outpatients,primarily group A β-hemolytic Streptococcus,Escherichia coli,and Staphylococcus aureus.Most of the strains(82.9％)were isolated from inpatients,mainly SS.aureus,E.coli,and H.influenzae.The prevalence of methicillin-resistant S.aureus(MRSA)in outpatients(24.5％)was lower than that in inpatient children(31.5％).The MRSA isolates from outpatients showed lower resistance rates to the antibiotics tested than the strains isolated from inpatient children.The prevalence of vancomycin-resistant Enterococcus faecalis or E.faecium and penicillin-resistant S.pneumoniae was low in either outpatients or inpatient children.S.pneumoniae,β-hemolytic Streptococcus and S.viridans showed high resistance rates to erythromycin.The prevalence of erythromycin-resistant group A β-hemolytic Streptococcus was higher in outpatients than that in inpatient children.The prevalence of β-lactamase-producing H.influenzae showed an overall upward trend in children,but lower in outpatients(45.1％)than in inpatient children(59.4％).The prevalence of carbapenem-resistant Klebsiella pneumoniae(CRKpn),carbapenem-resistant Pseudomonas aeruginosa(CRPae)and carbapenem-resistant Acinetobacter baumannii(CRAba)was 14％,11.7％,47.8％in outpatients,but 24.2％,20.6％,and 52.8％in inpatient children,respectively.The prevalence of multidrug-resistant E.coli,K.pneumoniae,Proteus mirabilis,P.aeruginosa and A.baumannii strains was lower in outpatients than in inpatient children.The prevalence of fluoroquinolone-resistant E.coli,ESBLs-producing K.pneumoniae,ESBLs-producing P.mirabilis,carbapenem-resistant E.coli(CREco),CRKpn,and CRPae was lower in children in outpatients than in inpatient children,but the prevalence of CRAba in 2021 was higher than in inpatient children.Conclusions The distribution of clinical isolates from children is different between outpatients and inpatients.The prevalence of MRSA,ESBL,and CRO was higher in inpatient children than in outpatients.Antibiotics should be used rationally in clinical practice based on etiological diagnosis and antimicrobial susceptibility test results.Ongoing antimicrobial resistance surveillance and prevention and control of hospital infections are crucial to curbing bacterial resistance.

Objective To investigate the changing antibiotic resistance profiles of E.coli isolated from patients in the 52 hospitals participating in the CHINET program from 2015 to 2021.Methods Antimicrobial susceptibility was tested for clinical isolates of E.coli according to the unified protocol of CHINET program.WHONET 5.6 and SPSS 20.0 software were used for data analysis.Results Atotal of 289 760 nonduplicate clinical strains ofE.coli were isolated from 2015 to 2021,mainly from urine samples(44.7±3.2)％.The proportion of E.coli strains isolated from urine samples was higher in females than in males(59.0％vs 29.5％).The proportion of E.coli strains isolated from respiratory tract and cerebrospinal fluid samples was significantly higher in children than in adults(16.7％vs 7.8％,0.8％vs 0.1％,both P＜0.05).The isolates from internal medicine department accounted for the largest proportion(28.9±2.8)％with an increasing trend over years.Overall,the prevalence of ESBLs-producing E.coli and carbapenem resistant E.coli(CREco)was 55.9％and 1.8％,respectively during the 7-year period.The prevalence of ESBLs-producing E.coli was the highest in tertiary hospitals each year from 2015 to 2021 compared to secondary hospitals.The prevalence of CREco was higher in children's hospitals compared to secondary and tertiary hospitals each year from 2015 to 2021.The prevalence of ESBLs-producing E.coli in tertiary hospitals and children's hospitals and the prevalence of CREco in children's hospitals showed a decreasing trend over the 7-year period.The prevalence of CREco in secondary and tertiary hospitals increased slowly.Antibiotic resistance rates changed slowly from 2015 to 2021.Carbapenem drugs(imipenem,meropenem)were the most active drugs amongβ-lactams against E.coli(resistance rate≤2.1％).The resistance rates of E.coli to β-lactam/β-lactam inhibitor combinations(piperacillin-tazobactam,cefoperazone-sulbactam),aminoglycosides(amikacin),nitrofurantoin and fosfomycin(for urinary isolates only)were all less than 10％.The resistance rate of E.coli strains to antibiotics varied with the level of hospitals and the departments where the strains were isolated,especially for cefazolin and ciprofloxacin,to which the resistance rate of E.coli strains from children in non-ICU departments was significantly lower than that of the strains isolated from other departments(P＜0.05).The E.coli isolates from ICU showed higher resistance rate to most antimicrobial agents tested(excluding tigecycline)than the strains isolated from other departments.The E.coli strains isolated from tertiary hospitals showed higher resistance rates to the antimicrobial agents tested(excluding tigecycline,polymyxin B,cefepime and carbapenems)than the strains from secondary hospitals and children's hospitals.Conclusions E.coli is an important pathogen causing clinical infection.More than half of the clinical isolates produced ESBL.The prevalence of CREco is increasing in secondary and tertiary hospitals over the 7-year period even though the overall prevalence is still low.This is an issue of concern.

Objective:To investigate effect of andrographolide(AG)on neuroinflammation in young epileptic rats by regulating cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)/cAMP response element binding protein(CREB)signaling pathway.Methods:SPF grade young SD rats were randomly divided into Control group,Model group,low-dose AG group(AG-L,125 mg/kg),high-dose AG group(AG-H,250 mg/kg)and high-dose AG+PKA inhibitor H-89 group(AG-H+H-89,250 mg/kg AG+2 mg/kg H-89),with 12 rats in each group.Epilepsy model of young rats was established by intraperitoneal injection of kainic acid(KA).Morris water maze test was used to detect learning and memory functions of rats.ELISA was used to detect levels of TNF-α,IL-10,malondialdehyde(MDA),superoxide dismutase(SOD)and cAMP in hippocampus of rats in each group.Histomorphology of hippo-campus was detected by Nissl staining.TUNEL test was usd to determine apoptosis rate of neurons in rat hippocampus.PKA and CREB mRNA expressions in hippocampus of rats in each group were detected by RT-qPCR.Western blot was used to detect protein expressions of PKA,Bax,Caspase-3,CREB,p-CREB and brain derived neurotrophic factor(BDNF)in hippocampus of rats in each group.Results:Compared with control group,escape latency,TNF-α and MDA levels in hippocampus,apoptosis rate of nerve cells,Bax and Caspase-3 protein expressions in Model group were obviously increased(P<0.05),target quadrant residence time,SOD,IL-10,cAMP levels,PKA,CREB mRNA and protein expressions,BDNF protein expression in hippocampus were decreased obviously(P<0.05),hippocampal tissue showed pathological damage and a large number of Nissl bodies were lost.Compared with Model group,cor-responding indexes of rats in AG-H group were contrary to the above(P<0.05),loss of Nissl corpuscles was reduced.H-89 alleviated improvement of AG on neuroinflammation in young epileptic rats.Conclusion:AG may reduce neuroinflammation in young epileptic rats by activating cAMP/PKA/CREB signaling pathway.

Objective:To investigate the neuroprotective effect of vanillin on experimental autoimmune encephalomyelitis(EAE)rats by regulating C-X-C motif chemokine ligand 12(CXCL12)/chemokine(C-X-C motif)receptor(CXCR4)signaling path-way.Methods:A total of 50 rats were injected with 400 μl guinea pig spinal cord and water in oil mixture of complete Freund's adju-vant to establish EAE rat model,and were divided into model group,low-dose vanillin group(50 mg/kg),medium-dose vanillin group(100 mg/kg),high-dose vanillin group(200 mg/kg)and positive drug group(5 mg/kg prednisone acetate),another 10 rats were only injected with the mixture of the same amount of normal saline and complete Freud adjuvant as control group,since the first day of mod-eling,all rats were given corresponding drugs by gavage for 16 consecutive days,and after modeling,rats in each group were scored for neurological function every day;HE and LFB staining were used to observe the pathology and demyelination of spinal cord in rats;levels of serum TNF-α,IL-1β and IL-6 were detected by ELISA;immunohistochemistry was used to detect expressions of CD68 and Iba-1 in spinal cord of rats;Western blot was used to detect expressions of CXCL12 and CXCR4 proteins in spinal cord of rats.Results:Compared with control group,rats in model group showed obvious infiltration of inflammatory cells,a large number of inflammatory cells gathered around the small blood vessels,and the structure of myelin sheath in spinal cord of rats was abnormal,accompanied by a large number of myelin sheath loss,the neurological function score,inflammatory infiltration score and demyelination score of spinal cord,serum TNF-α,IL-1β and IL-6 levels,spinal cord CD68 and Iba-1 proteins,CXCL12 and CXCR4 proteins expressions in-creased obviously(P<0.05);compared with model group,inflammatory cell infiltration and myelin sheath loss of rats in low,medium and high doses groups and positive drug group were obviously alleviated,neurological function score,inflammatory infiltration score and demyelination score of spinal cord,serum TNF-α,IL-1β and IL-6 levels,and expressions of CD68 and Iba-1 proteins in spinal cord decreased obviously(P<0.05),while expressions of CXCL12 and CXCR4 proteins in spinal cord further increased(P<0.05).Conclusion:Vanillin inhibits inflammatory response and alleviates nerve injury in EAE rats,and its mechanism may be related to acti-vation of CXCL12/CXCR4 signaling pathway.

Objective:To investigate the neuroprotective effect of vanillin on experimental autoimmune encephalomyelitis(EAE)rats by regulating C-X-C motif chemokine ligand 12(CXCL12)/chemokine(C-X-C motif)receptor(CXCR4)signaling path-way.Methods:A total of 50 rats were injected with 400 μl guinea pig spinal cord and water in oil mixture of complete Freund's adju-vant to establish EAE rat model,and were divided into model group,low-dose vanillin group(50 mg/kg),medium-dose vanillin group(100 mg/kg),high-dose vanillin group(200 mg/kg)and positive drug group(5 mg/kg prednisone acetate),another 10 rats were only injected with the mixture of the same amount of normal saline and complete Freud adjuvant as control group,since the first day of mod-eling,all rats were given corresponding drugs by gavage for 16 consecutive days,and after modeling,rats in each group were scored for neurological function every day;HE and LFB staining were used to observe the pathology and demyelination of spinal cord in rats;levels of serum TNF-α,IL-1β and IL-6 were detected by ELISA;immunohistochemistry was used to detect expressions of CD68 and Iba-1 in spinal cord of rats;Western blot was used to detect expressions of CXCL12 and CXCR4 proteins in spinal cord of rats.Results:Compared with control group,rats in model group showed obvious infiltration of inflammatory cells,a large number of inflammatory cells gathered around the small blood vessels,and the structure of myelin sheath in spinal cord of rats was abnormal,accompanied by a large number of myelin sheath loss,the neurological function score,inflammatory infiltration score and demyelination score of spinal cord,serum TNF-α,IL-1β and IL-6 levels,spinal cord CD68 and Iba-1 proteins,CXCL12 and CXCR4 proteins expressions in-creased obviously(P<0.05);compared with model group,inflammatory cell infiltration and myelin sheath loss of rats in low,medium and high doses groups and positive drug group were obviously alleviated,neurological function score,inflammatory infiltration score and demyelination score of spinal cord,serum TNF-α,IL-1β and IL-6 levels,and expressions of CD68 and Iba-1 proteins in spinal cord decreased obviously(P<0.05),while expressions of CXCL12 and CXCR4 proteins in spinal cord further increased(P<0.05).Conclusion:Vanillin inhibits inflammatory response and alleviates nerve injury in EAE rats,and its mechanism may be related to acti-vation of CXCL12/CXCR4 signaling pathway.

Objective:To investigate effect of andrographolide(AG)on neuroinflammation in young epileptic rats by regulating cyclic adenosine monophosphate(cAMP)/protein kinase A(PKA)/cAMP response element binding protein(CREB)signaling pathway.Methods:SPF grade young SD rats were randomly divided into Control group,Model group,low-dose AG group(AG-L,125 mg/kg),high-dose AG group(AG-H,250 mg/kg)and high-dose AG+PKA inhibitor H-89 group(AG-H+H-89,250 mg/kg AG+2 mg/kg H-89),with 12 rats in each group.Epilepsy model of young rats was established by intraperitoneal injection of kainic acid(KA).Morris water maze test was used to detect learning and memory functions of rats.ELISA was used to detect levels of TNF-α,IL-10,malondialdehyde(MDA),superoxide dismutase(SOD)and cAMP in hippocampus of rats in each group.Histomorphology of hippo-campus was detected by Nissl staining.TUNEL test was usd to determine apoptosis rate of neurons in rat hippocampus.PKA and CREB mRNA expressions in hippocampus of rats in each group were detected by RT-qPCR.Western blot was used to detect protein expressions of PKA,Bax,Caspase-3,CREB,p-CREB and brain derived neurotrophic factor(BDNF)in hippocampus of rats in each group.Results:Compared with control group,escape latency,TNF-α and MDA levels in hippocampus,apoptosis rate of nerve cells,Bax and Caspase-3 protein expressions in Model group were obviously increased(P<0.05),target quadrant residence time,SOD,IL-10,cAMP levels,PKA,CREB mRNA and protein expressions,BDNF protein expression in hippocampus were decreased obviously(P<0.05),hippocampal tissue showed pathological damage and a large number of Nissl bodies were lost.Compared with Model group,cor-responding indexes of rats in AG-H group were contrary to the above(P<0.05),loss of Nissl corpuscles was reduced.H-89 alleviated improvement of AG on neuroinflammation in young epileptic rats.Conclusion:AG may reduce neuroinflammation in young epileptic rats by activating cAMP/PKA/CREB signaling pathway.

Objective:To compare the mid-term clinical effects of AngioJet rheolytic thrombectomy assisted catheter-directed thrombolysis (ART+CDT) with catheter-directed thrombolysis (CDT) in the treatment of acute deep venous thrombosis of lower extremities.Methods:Ninety-one patients admitted to the Department from Jan 2016 to Dec 2017 were placed with inferior vena cava filters and divided into ART+CDT group (30 cases)and CDT group (61 cases). Total urokinase dosge, thrombolytic time, operative cost, length of hospital stay, detumescence rate, thrombus clearance rate, cumulative patency rate of lower limb veins, Villalta score at 2 years and 5 years, thrombosis recurrence rate and chronic venous insufficiency quality of life questionnaire were compared between the two groups.Results:The success rate of surgery was 100% in both groups, there was no mortality. There were significant differences in the short-term postoperative outcomes between the two groups in terms of total dosage of urokinase, thrombolysis time, total cost of surgery, length of hospital stay, detumescence rate, venous patency scores before and after treatment, and venous patency rate (all P<0.05). For the mid- and long-term postoperative outcomes of 2 and 5 years, there were no significant differences in the incidence of PTS, recurrence rate of thrombus, chronic venous function scale, and cumulative patency rate at 2 years (all P>0.05). Conclusions:ART+CDT has a significant advantage over CDT alone in terms of early efficacy and early reopening of blood flow in patients. Both ART+CDT and CDT have a low incidence of PTS and a low recurrence rate of thrombus in the mid-term follow-up, and both have satisfactory performance in the mid- and long-term efficacy of interventional treatment of deep venous thrombosis of lower limbs.

Objective To investigate the distribution and antimicrobial resistance profiles of the clinical isolates from wound pus in the CHINET Antimicrobial Resistance Surveillance Program from 2015 to 2021.Methods All the bacterial strains were isolated from wound pus samples from 2015 to 2021.The isolates were identified according to conventional methods.Antimicrobial susceptibility test was conducted by disk diffusion method or commercial automated susceptibility testing systems according to CHINET-specified uniform protocol.The results are interpreted according to the Clinical and Laboratory Standards Institute (CLSI) breakpoints (2021 Edition).Results A total of 90856 bacterial strains were isolated from wound pus samples from 2015 to 2021,of which gram positive bacteria accounted for 36.0％ (32729/90856) and gram negative bacteria accounted for 64.0％ (58127/90856).The most common bacterial species were Escherichia coli,Staphylococcus aureus,Klebsiella pneumoniae,Pseudomonas aeruginosa,and Enterococcus.About 88.9％ of these strains were isolated from inpatients and 11.1％ from outpatients.The strains collected from surgery department and internal medicine accounted for (53.4±3.6)％ (49191/90856) and (9.6±1.0)％ (8960/90856) on average over the 7-year period.E.coli showed low level resistance to carbapenems (1.1％).The prevalence of ESBLs-producing E.coli was 51.1％.More than 35％ of the E.coli isolates were resistant to cefotaxime,ciprofloxacin,and trimethoprim-sulfamethoxazole.The prevalence of ESBLs-producing K.pneumoniae was 29.7％.The prevalence of imipenem-resistant and meropenem-resistant K.pneumoniae varied from 2015 to 2021,but reached the peak level (12.5％ and 12.7％) in 2020.However,other Enterobacterales species showed low resistance rates to carbapenems.The prevalence of ESBLs-producing Klebsiella oxytoca and Proteus was 18.3％ and 32.5％,respectively.About 13.1％ and 10.6％ of P.aeruginosa isolates were resistant to imipenem and meropenem,respectively.However,71.1％ and 72.4％ of A.baumannii isolates were resistant to imipenem and meropenem,respectively.The overall prevalence of MRSA was 22.7％ in wound pus samples over the 7-year period.Three vancomycin-resistant strains and 122 linezolid-resistant isolates were identified in Enterococcus faecalis.Thirty-one vancomycin-resistant strains and 11 linezolid-resistant strains were detected in Enterococcus faecium.Conclusions The overall prevalence of MRSA,vancomycin-resistant Enterococcus (VRE),linezolid-resistant Enterococcus (LRE),ESBLs-producing Enterobacterales,and carbapenem-resistant organisms (CRO) in the isolates from wound pus samples was relatively lower than the corresponding prevalence in the total clinical isolates collected in the CHINET program.This finding suggests that the antimicrobial resistance profile of bacterial isolates may vary with the source of clinical samples.Therefore,we should strengthen the antimicrobial resistance surveillance for the isolates from different sites of infection.