To identify clinical viral diseases characterized by reproductive disorders and abortion,a quadruple qPCR method was established for simultaneous detection of PRV,PPV,PCV2 and AS-FV.Four pairs of specific primers and probes were designed according to the conserved genes of four viruses in the NCBI gene bank.The annealing temperature,primer concentration and probe concentration of the reaction were optimized,and the specificity,sensitivity and repeatability of the method were tested.The results showed that the method could not detect other pathogens except the target ones.The minimum detection limit of PRV,PPV,PCV2 and ASFV was 10 copies.Intra-group and inter-group repeatability tests showed that the coefficient of variation of C,values be-tween different batches was less than 3％,indicating that the method was highly specific,sensitive and stable.Establishment of an efficient and sensitive quadruple qPCR method provides technical reference for the clinical prevention and control of porcine pseudorabies virus disease,porcine circo-virus disease,porcine parvovirus disease and African swine fever.

This study investigates the effects of pseudorabies virus(PRV)infection on the antiviral immune signaling pathways and type Ⅰ interferon factors in mouse trigeminal ganglion(TG)cells.In this experiment,primary TG cells were infected with PRV at a multiplicity of infection(MOI)of 1,while mice were infected via a drop-nose method using 106,29 TCID50 of PRV.Real-time fluorescence quantitative PCR(qPCR),Western blot and ELISA were used to assess gene tran-scription,protein expression,and the secretion of IFN-α and IFN-β.The results indicated that PRV infection of mouse TG primary cells led to alterations in the gene and protein expression of RIG-Ⅰ,MAVS,and IRF3,as well as the phosphorylation of IRF3 and IKBα both in vivo and ex vivo.ELISA results showed that PRV infection could regulate the secretion of IFN-α and IFN-β in mouse primary TG cells and mouse TGs.The results of RIG-Ⅰ signaling pathway-related proteins and the secretion of IFN-a and IFN-β were analyzed using Western blot after using siRNA to interfere with RIG-Ⅰ expression in TG cells.The results showed that siRIG-Ⅰ successfully inter-fered with RIG-Ⅰ protein expression in TG cells and caused changes in the expression of down-stream proteins such as MAVS and IRF3,and also regulated the secretion of IFN-α and IFN-β in TG cells.Furthermore,the results indicated that PRV infection induced the expression of RIG-Ⅰ in mouse TG progenitor cells,regulating the antiviral immune response of type Ⅰ interferon factors in TG cells through the RIG-Ⅰ-MAVS-IRF3 signaling axis.Notably,PRV inhibited the expression of IRF3 in TG cells while significantly upregulating the expression of IFN-β during the later stages of infection,which may be an important factor in the important reason for the rapid mortality ob-served in mice during the late stages of PRV infection.This experiment elucidates part of the anti-viral immune mechanism mediated by the RIG-Ⅰ-MAVS-IRF3 signaling pathway in regulating type Ⅰ interferon factor after PRV infection of mouse TG cells,as well as the discovery of differ-ent trends of IRF3 protein changes in vivo and ex vivo,laying the groundwork for future in-depth studies.

To establish a TaqMan-based multiplex RT-qPCR method for the identification of Japa-nese encephalitis virus(JEV),Porcine reproductive and respiratory syndrome virus(PRRSV),and Classical swine fever virus(CSFV),this study designed and synthesized three pairs of specific primers and probes based on the conserved sequences of JEV E,PRRSV ORF6,and CSFV E2 a-vailable in the NCBI GenBank.By optimizing the reaction system and protocol,a multiplex RT-qPCR method for detecting these three viruses was developed and applied to the detection of clini-cal samples.The results showed that the established TaqMan multiplex RT-qPCR specifically am-plified the gene fragments of JEV,PRRSV,and CSFV,and did not amplify other non-target genes,indicating good specificity of the method.Intra-assay and inter-assay repeatability tests showed that the coefficient of variation(Cv)values were all below 3％,demonstrating that the method has ex-cellent repeatability.Sensitivity tests revealed that the minimum detectable amount for the recom-binant plasmids of the three viruses was 100 copies/pL.Using the established method,a total of 969 samples,including blood,aborted fetuses,semen,and deceased pigs,from 26 pig farms in Guizhou Province were tested.The detection rates were 34.3％(332/969)for JEV,28.3％(274/969)for PRRSV,and 19.8％(192/969)for CSFV.The co-infection rates were 10.1％(98/969)for JEV and PRRSV,12.1％(117/969)for JEV and CSFV,and 14.6％(141/969)for CSFV and PRRSV.Additionally,the triple co-infection rate of JEV,PRRSV,and CSFV was 7.9％(77/969).These results indicate that the TaqMan multiplex RT-qPCR method developed in this study is ef-fective for detecting these three viruses in pig farms,providing technical support for identifying vi-ral causes of reproductive disorders.

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 understand the distribution and antimicrobial resistance profiles of bacterial strains isolated from blood cultures at Yunyang County People's Hospital from 2019 to 2023.Methods The data of bacterial isolates from blood samples and the results of antimicrobial susceptibility testing were analyzed retrospectively from 2019 to 2023 at Yunyang County People's Hospital.Results A total of 3 789 bacterial strains were isolated from blood culture,including 1 931(51.0％)strains of Gram negative bacteria and 1 858(49.0％)strains of Gram positive bacteria.Coagulase negative Staphylococcus(33.3％),Escherichia coli(25.4％),Klebsiella pneumoniae(13.7％),Staphylococcus aureus(9.9％),and Enterobacter cloacae(1.8％)were the top five bacterial pathogens.Antimicrobial susceptibility testing showed that the prevalence of methicillin-resistant strains was 27.1％in S.aureus,34.5％in S.epidermidis,and 49.9％in other coagulase-negative Staphylococcus.Methicillin resistant strains(MRSA,MRSE,and other MRCNS)showed significantly higher resistance rates to most antibiotics than corresponding methicillin-susceptible strains(MSSA,MSSE,and other MSCNS).No staphylococcal isolates were resistant to vancomycin,teicoplanin,linezolid,or tigecycline.Enterococcus faecium showed significantly higher resistance rate to antibiotics than Enterococcus faecalis.No enterococcal strains were resistant to vancomycin,teicoplanin,linezolid,or tigecycline.No streptococcal isolates were found resistant to vancomycin or linezolid.Serratia marcescens strains had a resistance rate of 25.0％to carbapenems.All other Enterobacterales species showed a resistance rate of less than 10.0％to carbapenems.No Enterobacterales isolates were found resistant to tigecycline.The resistance rates of P.aeruginosa to imipenem and meropenem were 5.7％and 3.8％,respectively.No P.aeruginosa isolates were found resistant to colistin.The resistance rates of Acinetobacter baumannii to imipenem and meropenem were 41.4％and 38.0％,respectively.Conclusions The proportion of Gram negative bacteria is slightly higher than that of Gram positive bacteria in the bacterial isolates from blood samples at Yunyang County People's Hospital.The prevalence of MRSA and MRCNS is relatively high,while A.baumannii and S.marcescens showed high resistance rates to carbapenems.Antimicrobial resistance surveillance should be strengthened for the bacterial isolates from blood samples in order to learn the changing resistance profiles,use antibiotics reasonably,and prevent the spread of drug-resistant bacteria.

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.

This study was aimed at identifying the pathogenic bacteria responsible for the death of a young tiger at the Fujian Meihua Mountain South China Tiger Breeding Research Institute.Tissue samples from the lungs,liver,and intestines of the deceased tiger were collected,and the bacteria were cultured inasterile environment.The bacterial strains were characterized according to their morphological and molecular biological properties,including assessment of virulence genes and antibiotic resistance genes,mouse lethality tests,and antibiotic susceptibility evaluations.A predominant bacterial strain isolated from the liver of the deceased tiger was identified as enterotoxigenic Escherichia coli(ETEC)strain Tiger22513F.Phylogenetic analysis of the 16S rRNA gene revealed that the Tiger22513F strain exhibited close genetic similarity to the reference strain ETEC(MF919609.1),with 99.9%nucleotide similarity,and resided on the same evolutionary branch.The Tiger22513F strain contained 11 antibiotic resistance genes(tetA,sul1,sul3,cmlA,floR,blaTEM,blaSHV,blaCMY-2,qnrA,qnrS,and qnrD)along with five virulence genes(VT1,fyuA,tsh,iucD,and ST).Mouse lethality tests indicated significant pathogenicity toward mice,affecting primarily the lungs,liver,and intestines.Antibiotic susceptibility testing demonstrated that this strain exhibited resistance to various classes of beta-lactam antibiotics,as well as quinolones and aminoglycosides.This investigation successfully isolated a multi-drug resistant enterotoxigenic Escherichia coli strain with pronounced pathogenicity from the liver of a deceased tiger;thus providing valuable scientific insights for clinical diagnosis,as well as prevention and control measures,against ETEC infections in South China tigers.

To establish a TaqMan-based multiplex RT-qPCR method for the identification of Japa-nese encephalitis virus(JEV),Porcine reproductive and respiratory syndrome virus(PRRSV),and Classical swine fever virus(CSFV),this study designed and synthesized three pairs of specific primers and probes based on the conserved sequences of JEV E,PRRSV ORF6,and CSFV E2 a-vailable in the NCBI GenBank.By optimizing the reaction system and protocol,a multiplex RT-qPCR method for detecting these three viruses was developed and applied to the detection of clini-cal samples.The results showed that the established TaqMan multiplex RT-qPCR specifically am-plified the gene fragments of JEV,PRRSV,and CSFV,and did not amplify other non-target genes,indicating good specificity of the method.Intra-assay and inter-assay repeatability tests showed that the coefficient of variation(Cv)values were all below 3％,demonstrating that the method has ex-cellent repeatability.Sensitivity tests revealed that the minimum detectable amount for the recom-binant plasmids of the three viruses was 100 copies/pL.Using the established method,a total of 969 samples,including blood,aborted fetuses,semen,and deceased pigs,from 26 pig farms in Guizhou Province were tested.The detection rates were 34.3％(332/969)for JEV,28.3％(274/969)for PRRSV,and 19.8％(192/969)for CSFV.The co-infection rates were 10.1％(98/969)for JEV and PRRSV,12.1％(117/969)for JEV and CSFV,and 14.6％(141/969)for CSFV and PRRSV.Additionally,the triple co-infection rate of JEV,PRRSV,and CSFV was 7.9％(77/969).These results indicate that the TaqMan multiplex RT-qPCR method developed in this study is ef-fective for detecting these three viruses in pig farms,providing technical support for identifying vi-ral causes of reproductive disorders.

AIM To investigate the effect of Fuzheng Hefu Zhiyang Formula(FZHFZY)on psoriasis-like skin lesions and immune regulation in mice.METHODS In the in vivo experiment,30 BALB/c mice were randomly divided into the blank group,the model group,the dexamethasone group(1.5 g/kg of compound dexamethasone acetate cream),and the low-dose(2.5 g/kg)and high-dose(5 g/kg)FZHFZY groups,with six mice in each group.The experiment groups were treated with respective FZHFZY and dexamethasone,and the other groups were given normal saline for 10 consecutive days,during which psoriatic skin lesions were induced with imiquimod cream for 7 consecutive days.The mice had their area and severity of psoriasis assessed by PASI score;their histological changes of skin lesions.observed with Hematoxylin-eosin(HE)staining;their F4/80 ratio of skin lesions observed with immunohistochemical(IHC)staining;their protein expressions of P38,p-P38,Erk,p-Erk,P65 and p-P65 detected by Western blot;and their mRNA expressions of tumor necrosis factor-α(TNF-α),IL-17,IL-23 and IL-1β detected by RT-qPCR.In the in vitro research,the cultured RAW264.7 cells were divided into the blank group,the LPS group,and the FZHFZY groups(1 200,600,300,150 μg/mL).The cells had their protein expressions of P38,p-P38,Erk,p-Erk,P65 and p-P65 detected with Western blot;and their mRNA expressions of IL-6,TNF-α,IL-23 and IL-8 detected by RT-qPCR.RESULTS The in vivo experiment showed that compared to the model group,the FZHFZY groups demonstrated decreased PASI score(P＜0.01);improved epidermal thickening and parakeratosis of skin lesions as revealed by HE staining result and increased expression of F4/80 in IHC staining sections;decreased protein expression ratios of p-P38/P38,p-ERK/Erk and p-P65/P65 in skin(P＜0.05,P＜0.01);and reduced mRNA expressions of TNF-α,IL-17,IL-23 and IL-1β in the skin(P＜0.01).FZHFZY(0～2 400 μg/mL)showed no significant cytotoxicity towards RAW264.7 cells in vitro(P＞0.05).Compared to those of the LPS group,the cells exposed to FZHFZ at concentrations of 1 200 and 600 μg/mL demonstrated decreased protein expression ratios of p-P38/P38,p-ERK/Erk,and p-P65/P65(P＜0.05,P＜0.01);and significantly decreased mRNA expressions of TNF-α,IL-17,IL-23 and IL-1β(P＜0.01).CONCLUSION FZHFZY alleviates imiquimod-induced psoriatic lesions in mice and suppresses inflammatory response in LPS-stimulated RAW264.7 cells by inhibiting P38/Erk/NF-κB signaling pathway.