In order to explore the main pathogen of respiratory tract diseases in a sheep farm in Shaanxi province,the lung tissues of eight sheep died from respiratory tract diseases were tested for Mycoplasma,PPRV,foot-and-mouth disease virus and parainfluenza virus,respective.However,all of the above patho-gens tested were negative.Typical bacteria were isolated in the lung samples,identified morphologically,bi-ochemically,and finally by 16S rDNA profiling.Five P.aeruginosa strains,isolated from eight lung samples eventually(PA1-5),were subjected to a pathogenicity test in mice,antimicbial sensitivity test,and biofilm-forming test.The results showed that the mice were dead after challenge with the isolates in 24 hours.At the time of necropsy,the lungs,livers,spleens appeared enlarged with hemorrhage and sometimes with nec-rotic foci.PA1-5 isolates were sensitive to enrofloxacin and gentamicin,and resistant to ampicillin,amoxicil-lin,temicoxin,florfenicol,taloxectin,tevanistin and doxycycline.The biofilm-forming test showed that PA1 had moderate biofilm forming ability and PA2-5 had weak biofilm forming ability.The present study re-vealed that P.aeruginosa infection is the leading cause of sheep death.Enrofloxacin and gentamicin can be used alternately for treatment.In conclusion,this study provides a guidance for the prevention and treat-ment of sheep respiratory diseases caused by P.aeruginosa.
In order to establish the TLC identification method of Herba Lobelia in Erding Extract Powder,the identification method of Herba Lobelia in Erding Extract Powder was established from the aspects of sample pretreatment method,TLC developing agent,inspection method,TLC plate type,sample amount,etc.The stability of the detection method was studied from different manufacturers/batches of thin layer plates,different environmental temperatures and humidities.The TLC identification method of Herba Lobe-lia in Erding extract powder was successfully established.The results showed that the established TLC i-dentification method of Herba Lobelia was specific and stable,and could be used for qualitative identifica-tion of Herba Lobelia in Erding Extract Powder.
Porcine reproductive and respiratory syndrome(PRRS)is a significant disease in swine,charac-terized by blue-purple discoloration of both ears in infected pigs,also known as"blue ear disease".This epi-demic has caused substantial economic losses,and the PRRS virus is highly prone to variation and recombi-nation.The vaccination is the most important approach to prevent and control the disease,current available vaccines,including inactivated and live attenuated vaccines,as well as newer subunit and DNA vaccines,have not yet achieved the disease eradication.mRNA vaccines,which are notable for their exceptional safe-ty,efficacy,high yield,and convenience,are highly likely to achieve complete prevention and control of blue ear disease.The paper provides an overview of the current status of PRRS prevention and control,the pro-gress of mRNA vaccine research,and the potential of mRNA vaccines to control this disease,offering new directions for PRRS prevention and control.
Spotty liver disease(SLD)in chickens is an important infectious disease in poultry industry.SLD mainly affected in laying hens and broiler breeders.There are small multiple,grey/white spots in the liver surface of the in-fected chickens,and named after this pathological feature.Indicators of SLD include an acute drop in egg produc-tion,together with increased mortality,this lead to huge economic losses to the poultry industry.This article re-viewed the research advances on occurence,discovery of pathogen of diseases,the characteristics of the pathogen(Campylobacter hepatica),the epidemic characteristics,clinical symptoms and pathological lesions,diagnosis and control of SLD in recent years to provide references for further study and control of SLD.
Francisella tularensis(Ft)is a zoonotic intracellular pathogen and belongs to the Gram-negative bacteria,which can infect many types of cells.It is a pleomorphic facultative aerobe without spores and fla-gella.In vivo,Ft primarily infects and replicates in macrophages.Ft has evolved multiple mechanisms to an-tagonize the immune mechanism of the host,adapts to the environment in host macrophage cytoplasma,and delays the apoptosis of host cells.These strategies mainly include the enhancement of uptake bacteria,escape from phagosomes,antagonism of host oxidative defense,inhibition of host inflammatory response and maintenance of self-stability,etc.This paper mainly reviews the research progress on the pathogenic mechanism of Ft,in order to provide references for the research of this pathogen.
In order to understand the infection of porcine pseudorabies virus(PRV)in different regions,sites and groups in Henan,9 540 serological samples and 1 649 tissue samples were collected from 253 sites with different scales in 18 cities in Henan from November 2020 to October 2021.Serum antibody was detec-ted by ELISA kit,and PRV nucleic acid in tissue samples were detected by fluorescence PCR.In addition,gE gene amplification,sequencing and genetic variation analysis were carried out on some positive samples.Serological test results showed that gE antibodies against PRV in pigs were detected in different areas of Henan,the average individual positive rate of gE antibodies against PRV was 26.03％,and the positive rate at farms/herds level was 54.15％.The average individual and farm/herd positive rates of commercial gener-ation farms were the highest in different farms/herds.Among the pig herds at different growth stages,nursery piglets had the highest individual positive rate.In addition,the highest individual positive rate was in winter.Results of pathogenic detection of tissue samples showed that a total of 54 virus nucleic acid posi-tive strains were detected,with an average individual positive rate of 3.27％.Among them,4 PRV strains were sequenced and analyzed for genetic evolution.The nucleotide homology between the gE gene sequences of the 4 PRV strains was 99.5％-99.9％,the homology with the classical foreign strain was 99.2％-99.5％,and the homology with the domestic epidemic variant strain was 99.6％-99.9％.They belonged to the geno-type Ⅱ group,all of which were variant strains.The results showed that PRV infection in pig farms in Henan was relatively common,and the epidemic strain was a variant strain.This study will provide an im-portant data reference for the screening,purification and comprehensive prevention and control of PRV im-mune strains in pig farms in Henan.
Adeno-associated virus(AAV),particularly AAV9 that migrates from terminal axons to neu-rons,is a powerful tool for studying neural circuits and brain function.Using a combination of vesicular glu-tamate transporter 2(VGlut2)gene knockout in mice and stereotactic brain injections,the AAV9-DIO-ChR2-EGFP virus was injected into the locus coeruleus.The study investigated the effects of different injec-tion doses on the range of viral infection and mouse weight.The results indicated that,compared to the higher injection volume(1 μL),the lower injection volume(0.5 μL)can confine AAV9-DIO-ChR2-EGFP to the locus coeruleus.Three weeks after injecting AAV9-DIO-ChR2-EGFP,the infection range extended from the locus coeruleus to the primary motor cortex(Ml),thalamus,araphe palidus nucleus(Rpa),and cervical spinal cord(CSC).Subsequent testing showed that the low dose of AAV9(0.5 μL)had no effect on mouse body weight(P=0.979 5).These results demonstrate that a low injection dose(0.5 μL)can par-tially limit the expression range of AAV and that intracranial AAV9 injection does not alter mouse body weight.
To study the pathogenicity,serotype distribution,virulence gene and drug resistance of Salmonel-la in chicken processing and retail links in Chengde,Hebei province,in this experiment,257 samples from chicken slaughterhouses,processing plants and retail stores in Chengde,Hebei province were collected from 2021-2022 for isolation and identification of Salmonella.The pathogenicity,serotype,virulence gene and drug resistance of the isolated strains were detected by artificial infection mouse test,glass plate agglutina-tion test,PCR method and K-B drug sensitive paper method.The results showed that 70 pathogenic Salmo-nella strains were isolated from 257 samples;There are 12 serotypes in 70 strains of Salmonella,among which Salmonella enteritidis(24.3％),Salmonella typhimurium(21.4％)and Salmonella dublin(17.1％)are the dominant serotypes;The detection rates of virulence plasmid genes(spvA,spvB,spvC,spvR)were between 12.9％and 88.6％,and the detection rates of virulence island genes(SPI-1,SPI-2,SPI-3,SPI-5)were between 27.0％and 90.0％;The drug resistance rate to 7 drugs,such as amoxicillin,ampicillin and sulfamethoxypyrimidine,was more than 51.4％,and the drug resistance rate to other drugs was between 5.7％and 40％,with 10(15.0％),9(20.0％)and 8(17.1％)drugs being the main resistance;The detection rate of drug resistance genes Sul1,Sul2,Sul3,TetA,TetM,TetR,aac(3)-Ⅰ v and aac(6')-Ⅰb was 45.7％-97.1％,and the detection rate of other drug resistance genes was between 8.6％and 17.1％.There was basically positive correlation between drug resistance phenotype and drug resistance genes(except amidohols and polymyxin).The results showed that 70 strains of pathogenic Salmonella iso-lated from chicken processing and retail links in Chengde area had multiple serotypes,carried multiple viru-lence genes,serious drug resistance,and carried multiple drug resistance genes.
In order to understand the differences in viremia and antibody levels in pigs immunized with live attenuated commercial porcine reproductive and respiratory syndrome vaccines A and B,100 35 day old re-serve sows were randomly selected from the reserve sow farm and divided into groups A and B.After grouping,the pigs were mixed bred for 14 days.At the age of 50 days,50 reserve sows in group A were im-munized with vaccine A,and 50 reserve sows in group B were immunized with vaccine B(1 portion per head).On days 0,1,2,3,5,7,10,14,21,28,and 35 of vaccine immunization,10 samples of sera were ran-domly collected and isolated from pigs in each experimental group.The viral load of porcine reproductive and respiratory syndrome was detected by fluorescence quantitative PCR,and the antibody to porcine re-productive and respiratory syndrome virus was detected by ELISA.The results showed that:After immuni-zation with B vaccine,the duration of the experimental porcine reproductive and respiratory syndrome vire-mia period was longer,lasting up to 35 days;After immunization with vaccine A,the experimental porcine reproductive and respiratory syndrome virus load was higher;After immunization with B vaccine,the varia-tion trend of N-protein antibody level in pigs was more stable;After immunization with B vaccine,the level of GP protein antibody in pigs was higher.This indicates that the immune effect of vaccine B is better than that of vaccine A.
The problem of bacterial resistance to antibiotics is becoming more and more serious,and it is dif-ficult to develop new antibiotics.In this case,people urgently need a new kind of therapeutic agent to re-place antibiotics for the prevention and treatment of bacterial diseases.Phage,which can be seen everywhere in nature,has gradually returned to people's field of vision.Phage has many advantages,such as variety,high specificity,strong safety and low cost,and people's research on phage has gradually deepened.Phage therapy has played a role in animal husbandry industry and even in human clinical practice.This paper briefly de-scribes the development process of phage therapy,introduces the drug delivery routes and the application of phage therapy in animal husbandry industry,and provides some reference for the future use of phages in animal husbandry industry.
In order to study the isolation,culture methods and biological characteristics of the fibroblasts of Equus kiang,the ear skin tissue of a 7-year-old Equus kiang was used.The primary cells were obtained by adherent method.The cells were purified with trypsin digestion method and a technique of differential an-choring velocity.The cells were identified by cellular morphology,growth curve,cell cycle and immunofluo-rescence staining.The results showed that the growth curve of fibroblasts was S-shaped,and the cells grew well.The expression of FSP-1 was confirmed positive by immunofluorescence staining.This study estab-lished the method of isolation,culture and identification of skin fibroblasts from ears skin of adult Equus kiang in vitro,which laid a foundation for the protection of germplasm resources in Equus kiang and the research at the cellular and molecular levels.
To establish a rapid and accurate detection method for the diagnosis of respiratory diseases in pigs caused by single or mixed infection of Streptococcus suis(SS),Actinobacillus pleuropneumoniae(App),Pasteurella multocida(Pm),Hemophilus parasuis(Hps),Bordetella bronchisepticus(Bb)and Myco-plasma hyopneumoniae(Mhp),amultiplex PCR method was established that can simultaneously detect SS,App,Pm,Hps,Bb and Mhp by designing the specific primers based on gdh(SS),apx Ⅳ A(App),KMT1(Pm),16S rRNA(Hps),fla(Bb)and p36 ldhi(Mhp)genes corresponding to the above six patho-gens and optimizing reaction conditions in this study.The results showed that this method was highly spe-cific,only for SS,App,Pm,Hps,Bb and Mhp,and negative for E.coli,Proteus mirabilis,Streptococcus lactis and Staphylococcus aureus.The sensitivity is high,and the lowest simultaneous detection limits of six pathogenic bacteria DNA templates are SS 8.66 × 102 copies/μL,App 1.05 × 104 copies/μL,Pm 8.61 × 102 copies/μL,Hps 9.01 ×102 copies/μL,Bb 7.54×102 copies/μL,Mhp 3.86×103 copies/μL,respectively.469 clinical samples from some pig farms of 9 cities(prefectures)in Guizhou province were detected by this multiplex PCR and each single PCR method.The results showed that the positive detection rates of multiplex PCR were 0.85％(4/469)for App,15.35％(72/469)for Pm,59.49％(279/469)for SS,52.67％(247/469)for Hps,6.4％(30/469)for Mhp,and 5.12％(24/469)for Bb.The mixed infection was mainly caused by SS and Hps,with a positive detection rate of 30.92％(145/469),followed by Pm,SS and Hps,with a positive detection rate of 7.04％(33/469),and the proportion of other mixed infections was lower.The total positive coincidence rate of multiplex PCR and single PCR was 96.76％.The multiplex PCR de-tection method established in this study provides technical support for rapid clinical detection and epidemi-ological investigation of mixed infections of SS,App,Pm,Hps,Bb and Mhp.
Virus seriously endangers the health of human and animal.Currently,the prevention and control of viral diseases still mainly rely on the vaccine immunization.However,due to the variety of viruses and frequent mutations,immunization alone has been unable to play an effective role in prevention and control.Therefore,the development of ideal anti-viral drugs has become the focus of scholars at home and abroad in recent years.At present,there are few varieties of anti-viral drugs in clinical application,with unsatisfactory effects and great side effects.Therefore,traditional Chinese medicine(TMC)has attracted the attention of many scholars due to its unique advantages in disease prevention and treatment.The study showed that a variety of TCM decoction pieces,compound preparations and their active components all had strong inhibi-tory effect on virus.In this paper,combined with the pathogenesis of viral diseases,the research results of anti-viral mechanism of TMC were reviewed,in order to lay a theoretical foundation for the research and development of high efficiency and low toxicity antiviral drugs in veterinary clinic.
To provide data support for the development of oral preparations for the novel coupling compound florfenicol sulfathiazole(FST),high performance liquid chromatography was used to determine FST in five solution media:artificial intestinal fluid without protease,artificial intestinal fluid,artificial gastric juice without protease,artificial gastric juice,and the content of intestinal flora culture medium of rats at differ-ent times were studied to determine the difference in their stability.The results showed that the content of FST remained basically stable in 0-6 h of artificial gastric juice and artificial gastric juice without protease;After incubation in artificial intestinal fluid and artificial intestinal fluid without protease for 30 min,the chromatographic peak was completely degraded,and the emerging chromatographic peak time was the same as that florfenicol and sulfathiazole reference substance under the same chromatographic conditions.It was concluded that the metabolites of FST were florfenicol and sulfathiazole;FST degradation occurred in the intestinal flora.The content of FST decreased rapidly at 0-8 h,and stabilized to 50％at 8-12 h.These re-sults indicated that FST is obviously degraded in artificial intestinal fluid and tends to be stable in artificial gastric juice,and the intestinal flora also has a certain influence on its stability.
To establish an indirect competitive enzyme-linked immunosorbent assay(ic-ELISA)method for the detection of zilpterol(ZIL)residues,in this study,based on the obtained rabbit anti-ZIL polyclonal an-tibody serum and the prepared complete antigen as the coating source,an ic-ELISA method for the detec-tion of ZIL residues was established by optimizing the reaction conditions;The results showed that the best dilution ratio of rabbit serum was 1:6 000,and the best antigen coating concentration was 2 μg/mL,the half inhibition concentration(IC50)is 0.317 ng/mL,the linear detection range(IC20-IC80)is 0.136-1.181 ng/mL,and the minimum detection limit(LOD,IC10)is 0.081 ng/mL.After optimization,the optimal pH of the detection system is 7.4,the salt concentration is≤0.4 mol/L,the content of methanol,ethanol,ace-tone and DMSO is≤5％,the content of acetonitrile is≤10％,and the concentration of bovine urine in the detection matrix is≤15％.The detection method has good stability and specificity.The addition recovery rate of intra-batch and inter-batch repeated test samples is 101％-1 12％and 101％-120％respectively,and the coefficient of variation is less than 10％,The correlation coefficient between the test results and HPLC-MS test results is R2=0.990 6.The detection method is fast,sensitive,accurate,reproducible and low detec-tion limit,and is suitable for high-throughput detection and on-site rapid screening of ZIL residues.
In order to overcome the problem that GMP/GCP/GLP inspectors for veterinary drugs are unable to carry out on-site supervision,which due to the impact of COVID-19 or animal quarantine requirements in animal testing sites,the Animal Husbandry and Veterinary Bureau of the Ministry of Agriculture and Ru-ral Affairs launched an innovative method of"remote video examination of veterinary drugs"in April 2022.They help veterinary drug production enterprises to obtain production license and help the veterinary drug research institutions into research work as soon as possible.This paper introduces the background and ap-plication of remote video inspection in the field of veterinary drug supervision in China,analyzes the advan-tages and existing problems of remote video inspection,and puts forward suggestions on the promotion and application of remote video examination,providing reference for the popularization of remote video exami-nation in the administrative law enforcement of agricultural and rural field.
In this study,two cases of feline infectious peritonitis(FIP)were detected and diagnosed using autopsy,histopathology and immunohistochemistry(IHC),and the ORF 7ab,N and S genes of feline in-fectious peritonitis virus(FIPV)were amplified by RT-PCR in two tissue samples.The genes were se-quenced and subjected to genetic evolutionary analysis to elucidate the genetic evolutionary characteristics of the virus.The results showed that both cases presented with the typical gross lesions of mixed FIP,with an accumulation of plasma fibrinous exudate in the peritoneal cavity and scattered or diffuse distribution of small grey-white nodules on the peritoneal plasma surface.Histopathology showed the foci of inflammatory cell infiltration of variable size attached to the peritoneal surface,as well as necrotizing enterocolitis,inter-stitial pancreatitis and interstitial pneumonia.Strong positive signals specific for FPIV were seen in the foci of inflammatory cell infiltration,in the spleen and the pancreas.The genetic homology and genetic evolution analysis showed that the genes of the two cases belonged to FCoV type Ⅰ.IMAU No.11685 had the highest homology with ZJU1709 strain(MT239440)from Hangzhou,Zhejiang province,and was the closest rela-tive;IMAU No.11824 had the highest homology with QS strain(MW030108)from Wuhan,Hubei prov-ince,and was the closest relative.It indicateed that the two FIPV cases originated from a common ancestor with the domestic epidemic strain,in which the ORF 7ab and N genes are relatively conserved with insig-nificant variation,and some variation occurred in the S gene.It can provide data reference for the molecular epidemiological study and prevention and control of FIP in China.
To reveal the species of Fasciola fluke in yellow cattle,adult parasites of Fasciola were isolated from the liver of a yellow cattle in a beef cattle slaughterhouse in Jiyuan of Henan province and observed morphologically.Then the parasites were further identified by sequence analysis based on the ribosomal ITS1 and ITS2 regions and mitochondrial nad1 and cox1 genes.Sequence analysis based on ITS1 and ITS2 regions showed that the isolates JY003 and JY004 from the affected yellow cattle in this study were the Fh/Fg hybrid type of Fasciola.The nad1 and cox1 sequences of JY003 and JY004 were more similar to that of F.gigantica than F.hepatica,especieally the nad1 sequences of the two isolates were 100％identi-cal to that of the F.gigantica isolates from Yunnan of China,Japan and Korea.In the phylogenetic trees based on the nad1 and cox1 genes,the two isolates in this study were clustered into the same branch with the reference strains of F.gigantica.This is the first report of the Fh/Fg hybrid type of Fasciola infection in a yellow cattle from Henan province,providing important basic data for the prevention and control of fasciolosis in animals and humans.
In order to make the bone specimen durable and find a way to reduce bone damage and effectively degrease and bleach,10 pairs of ribs and other bones of 210-day-old male alpaca with similar size were taken as the research objects,and the degreasing and bleaching effects of temperature,ammonia concentra-tion and action time on animal bones were tested.Firstly,different temperature groups(20,25,30,35℃)were set up,and 100 mL/L H2 O2 was mixed with 2,4,6,8,10 mL/L ammonia water respectively,and then degreased and bleached.After 4 h,the effect was observed,the 100 mL/L H2O2 and the optimum ammonia water concentration mixed degreased and bleached solution were screened out,and the optimum tempera-ture was determined.For different types of bones(hindlimb bone,forelimb bone,skull,rib and small bones),the degreasing and bleaching test was carried out under the optimum temperature condition by usingthe selected degreasing and bleaching solution,and the optimum time of degreasing and bleaching was recorded.The results showed that the mixed solution of 100 mL/L H2O2 and 6 mL/L ammonia water had the best degreasing and bleaching effect on alpaca ribs at 25-30℃,the degreasing and bleaching time was 4 h;The best degreasing and bleaching effect can be achieved at 9,8,6,4 h and 2 h for the symbolic bones such as hindlimb bones,forelimb bones,skull bones,ribs and small bones.100 mL/L H2O2 and 6 mL/L ammonia water have good degreasing and bleaching effect at 25-30 ℃,and the optimal degreasing and bleaching time is positively correlated with bone size,density and bone marrow cavity volume.
34 cases of Helicobacter pylori infections in dogs and cats,confirmed by clinical symptoms and immunofluorescence,were treated by triple therapy or quadruple therapy,combined with microecological preparations and other symptomatic supportive therapies.85％of the patients recovered and had a good prognosis.The results provide some reference for the diagnosis and treatment of helicobacter pylori infec-tions in dogs and cats.
