Diagnosis and Prevention of Swine Foot-and-mouth Disease

This paper introduces the characteristics of swine foot-and-mouth disease from the aspects of pathogen,epidemiology,clinical symptoms,and anatomical symptoms,and puts forward clinical comprehensive diagnosis and laboratory diagnostic methods.The disease is distinguished with similar diseases,such as swine pox,porcine vesicular stomatitis,and swine vesicular disease.Finally,the prevention and control measures of the disease are proposed.

Application of traditional Chinese herbal medicine in the prevention and treatment of swine viral infectious diseases

This study aims to explore the current application status and development prospects of Chinese herbal medicine in preventing and treating swine viral infectious diseases over the past five years.By adopting the method of literature review,we collect,organize,and analyze relevant research literature,with the goal of summarizing and summarizing the research progress in this field.Through research,we found that swine infectious diseases have caused serious economic losses in the breeding industry and that some diseases cannot be fully protected by using vaccines.Therefore,we need new means to prevent diseases.The use of Chinese herbal medicine for the prevention and treatment of related diseases has become a reliable means.This study first briefly introduces the common infectious diseases of pigs and the risks and challenges faced by prevention and treatment,then reads the literature comparing the treatment with Western medicine and traditional Chinese medicine,proving the reliability of traditional Chinese medicine treatment and the unique advantages of Chinese herbal medicine.Afterwards,we summarized the literature on the prevention and treatment of related swine diseases with Chinese herbal medicine in the past five years,and finally made a summary and outlook,hoping to provide ideas for relevant researchers and workers.

The Complete Genomic Sequence of a Foot-and-Mouth Disease Virus Isolated from the Swine

The complete genomic sequence of foot-and-mouth disease virus (FMDV) Chinese strain OH/CHA/99 was determined. The 8040 nt sequence and the deduced amino acid sequence werecompared with FMDV sequences published. The results showed that OH/CHA/99 shared highersequence homology with OTYTW/97, indicating their close genetic relationship. However,the strain had lower sequence identity with O1/Kaufbeuren/66 strain. Besides, largedeletions in 3A coding region were observed in OH/CHA/99. It was shown that the poly (A)tail of OH/CHA/99 had 56 As at least.

Effect of Attenuated Highly Pathogenic Pig Reproductive and Respiratory Syndrome(HP-PRRS) TJM-F92 Strain Vaccine on Immune Antibody Levels against Classical Swine Fever(CSF) and Foot-and-Mouth Disease(FMD)

Effects of attenuated highly pathogenic pig reproductive and respiratory syndrome（HP-PRRS）TJM-F92 strain vaccine on immune antibody level against classical swine fever（CSF）and foot-and-mouth disease（FMD）were studied from October 8 to November 12 in 2014,in order to optimize vaccination program of CSF,HP-PRRS and FMD and to provide scientific guidance for animal disease control and prevention work.The results showed that attenuated HP-PRRS（TJMF92 strain）vaccine had no significant effect on immune antibody level of hog cholera lapinized virus（HCLV,ST passage cell vaccine）attenuated vaccine and FMD-O inactivated vaccines（OZK/93 strain）,and single or combined use of three vaccines received good immunization effects.

Cloning and Prokaryotic Expression of VP1 Gene of Foot-and-Mouth Disease Virus (FMDV) Type O

According to the complete genome of foot-and-mouth disease virus(FMDV)type O,a pair of special primers was designed to amplify VP1 gene.The VP1 gene was amplified by RT-PCR and subsequently inserted into the expression vector pGEX-6p-1 and induced by IPTG.Then SDS-PAGE showed the expressed protein was 51 kD in molecular weight.Then the product was purified by GSTrap FF columns.The product was detected through Western-blot that showed the protein has antigenicity.It provided fundamental data and materials for further investigation on diagnosis method of FMDV.

Effect of amino acid mutation at position 127 in 3A of a rabbitattenuated foot-and-mouth disease virus serotype Asia1 on viral replication and infection

An amino acid mutation(R127→I) in the 3A non-structural protein of an FMDV serotype Asia1 rabbit-attenuated ZB strain was previously found after attenuation of the virus. To explore the effects of this mutation on viral replication and infection, the amino acid residue isoleucine(I) was changed to arginine(R) in the infectious cDNA clone of the rabbit-attenuated ZB strain by sitedirected mutagenesis, and the R127-mutated virus was rescued. BHK monolayer cells and suckling mice were inoculated with the R127-mutated virus to test its growth property and pathogenicity, respectively. The effects of the R127 mutation on viral replication and virulence were analyzed. The data showed that there was a slight difference in plaque morphology between the R127-mutated and wild-type viruses. The growth rate of the mutated virus was lower in BHK-21 cells and its virulence in suckling mice was also attenuated. This study indicates that the R127 mutation in 3A may play an important role in FMDV replication in vitro and in pathogenicity in suckling mice.

Single amino acid substitution of VP1 N17D or VP2 H145Y confers acid-resistant phenotype of type Asia1 foot-and-mouth disease virus

Infection by foot-and-mouth disease virus(FMDV) is triggered by the acidic pH in endosomes after virus uptake by receptor-mediated endocytosis. However, dissociation of the FMDV 146S particle in mildly acidic conditions renders inactivated foot-and-mouth disease(FMD) vaccines much less effective. Type Asia1 FMDV mutants with increased resistance to acid inactivation were selected to study the molecular basis of viral resistance to acid-induced disassembly and improve the acid stability of FMDV. Sequencing of capsid-coding regions revealed four amino acid replacements(VP1 N17D, VP2 H145Y, VP2 G192D, and VP3 K153E) in the viral population of the acid-selected 10th passage. We performed single or combined mutagenesis using a reverse genetic system, and our results provide direct experimental evidence that VP2 H145Y or VP1 N17D substitution confers an acid-resistant phenotype to type Asia1 FMDV.

B Cell Epitopes within VP1 of Type O Foot-and-mouth Disease Virus for Detection of Viral Antibodies

In this study, the coding region of type O FMDV capsid protein VP1 and a series of codon optimized DNA sequences coding for VP1 amino acid residues 141-160 （epitopel）, tandem repeat 200-213 （epitope2 （＋2）） and the combination of two epitopes （epitopel-2） was genetically cloned into the prokaryotic expression vector PPRoExHTb and pGEX4T-1, respectively. VP1 and the fused epitopes GST-E1, GST-E2 （＋2） and GST-E1-2 were successfully solubly expressed in the cytoplasm of Escherichia coli and Western blot analysis demonstrated they retained antigenicity. Indirect VP1-ELISA and epitope ELISAs were subsequently developed to screen a panel of 80 field pig sera using LPB-ELISA as a standard test. For VP1-ELISA and all the epitope ELISAs, there were clear distinctions between the FMDV-positive and the FMDV-negative samples. Cross-reactions with pig sera positive to the viruses of swine vesicular disease virus that produce clinically indistinguishable syndromes in pigs or guinea pig antisera to FMDV strains of type A, C and Asia1 did not occur. The relative sensitivity and specificity for the GST-E1 ELISA, GST-E2 （＋2）, GST-E1-2 ELISA and VP1-ELISA in comparison with LPB-ELISA were 93.3% and 85.0%, 95.0% and 90%, 100% and 81.8%, 96.6% and 80.9% respectively. This study shows the potential use of the aforementioned epitopes as alternatives to the complex antigens used in current detection for antibody to FMDV structural proteins.

Amplification and Characterization of Bull Semen Infected Naturally with Foot-and-mouth Disease Virus Type Asia1 by RT-PCR

To investigate the security of semen biologically, 15 bull semen samples were collected (of which 5 exhibited clinical signs of Foot-and-mouth disease) and identified by RT-PCR and virus isolation. The results indicated that the semen of the infected bulls were contaminated by Foot-and-mouth disease virus (FMDV), but FMDV was not detected in semen samples from those bulls not showing clinical signs of Foot-and-mouth disease (FMD). This is the first report of the presence of FMDV in bull semen due to natural infection in China. The analysis of the partial sequence of the VP1 gene showed that the virus strain isolated from semen has 97.9% identity with the virus isolated from vesicular liquid of infected bulls showing typical signs of FMD and belonged to the same gene sub-group.

Expression and Immunological Analysis of Capsid Protein Precursor of Swine Vesicular Disease Virus HK/70

VP1, a capsid protein of swine vesicular disease virus, was cloned from the SVDV HK/70 strain and inserted into retroviral vector pBABE puro, and expressed in PK15 cells by an retroviral expression system. The ability of the VP1 protein to induce an immune response was then evaluated in guinea pigs. Western blot and ELISA results indicated that the VP1 protein can be recognized by SVDV positive serum, Furthermore, anti-SVDV specific antibodies and lymphocyte proliferation were elicited and increased by VP1 protein after vaccination. These results encourage further work towards the development of a vaccine against SVDV infection.

Association of swine influenza H1N1 pandemic virus(SIV-H1N1p) with porcine respiratory disease complex in sows from commercial pig farms in Colombia

Porcine respiratory disease complex （PRDC） is a serious health problem that mainly affects growing and finishing pigs. PRDC is caused by a combination of viral and bacterial agents, such as porcine reproductive and respiratory syndrome virus （PRRSV）, swine influenza virus （SIV）, Mycoplasma hyopneumoniae （Myh）, Actinobacillus pleuropneumoniae （APP）, Pasteurella multocida and Porcine circovirus 2 （PCV2）. To characterize the specific role of swine influenza virus in PRDC presentation in Colombia, 11 farms from three major production regions in Colombia were examined in this study. Nasal swabs, bronchial lavage and lung tissue samples were obtained from animals displaying symptoms compatible with SIV. Isolation of SIV was performed in 9-day embryonated chicken eggs or Madin-Darby Canine Kidney （MDCK） cells. Positive isolates, identified via the hemagglutination inhibition test, were further analyzed using PCR. Overall, 7 of the 11 farms were positive for SIV. Notably, sequencing of the gene encoding the hemagglutinin （HA） protein led to grouping of strains into circulating viruses identified during the human outbreak of 2009, classified as pandemic H1N1-2009. Serum samples from 198 gilts and multiparous sows between 2008 and 2009 were obtained to determine antibody presence of APP, Myh, PCV2 and PRRSV in both SIV-H1Nlp-negative and -positive farms, but higher levels were recorded for SIV- HI Nlp-positive farms. Odds ratio （OR） and P values revealed statistically significant differences （p〈0.05） in PRDC presentation in gilts and multiparous sows of farms positive for SIV-HINlp. Our findings indicate that positive farms have increased risk of PRDC presentation, in particular, PCV2, APP and Myh.

Comparison of Three ELISA Kits for the Differentiation of Foot-and-mouth Disease Virus-infected from Vaccinated Animals

研究被执行验证工具包为 FMDV 的区别在中国开发了的 3 FMDV 3ABC-I-ELISA 感染并且种牛痘的动物。从天真、种牛痘的牛以及从被感染了的牛的 sera 的集合被商业诊断工具包对 FMDV 的 nonstructural 蛋白质(NSP ) 为抗体测试， Ceditest 吗？FMDV-NS (Ceditest？工具包) ， UBI？FMDV NONSTRUCTURAL 蛋白质 ELISA 方向插入(UBI？工具包) 并且一个 FMDV 3ABC-I-ELISA 工具包在 Lanzhou 发展了兽医研究院。三个工具包的测试参数(敏感和特性) 被决定，并且从 FMD 3ABC-I-ELISA 工具包获得的结果与从二个外国工具包获得了那相比。结果显示巧合在 FMDV 3ABC-I-ELISA 和 Ceditest 之间评价吗？工具包 98.05% 是，并且在 FMDV 3ABC-I-ELISA 和 UBI 之间的巧合率？工具包是 94.4% ；两 Ceditest 的敏感？并且 FMDV 3ABC-I-ELISA 工具包是 100% 。然而， UBI 的敏感？工具包仅仅是 81.8% 。与从天真或种牛痘的非感染的动物的 sera，所有测试的特性超过了 90% 。关键词 Foot-and-mouth 疾病病毒(FMDV )- 非结构的蛋白质 3ABC - ELISA CLC 数字 S852.65 基础项目：国家鈥 ? 73 鈥 ? 研究工程(G199901190， 2005CB23201 ) ；国际原子能机构(国际原子能机构)(10697/R2 )

Adverse Effects of Inactivated Foot-and-Mouth Disease Vaccine—Possible Causes Analysis and Countermeasures

Foot-and-mouth disease (FMD) is an infectious and sometimes fatal viral disease that affects cloven-hoofed animals, and Chinese government adopts compulsory immunization measures for FMD. The adverse effects of FMD vaccine to pigs, cattle and goats have been reported increasingly frequent during the spring and autumn seasons when large numbers of farm livestock are vaccinated. The financial losses caused by vaccine adverse effects have been a serious concern for both farmers and primary prevention personnel. There are various causative factors reported to involve into adverse effect of FMD vaccine, including the inappropriate vaccine production, transportation and storage, livestock poor tolerance, and unqualified vaccinating manipulations. Symptomatic treatment and early drug prevention have a certain effect on the adverse effects. To analyze causes and propose countermeasures, in the current study possible reasons during the production and processing procedures of inactivated FMD vaccine were reviewed and corresponding countermeasures were recommended. The review may provide references for better use of vaccine to prevent FMD.

Review of Air Dispersion Modelling Approaches to Assess the Risk of Wind-Borne Spread of Foot-and-Mouth Disease Virus

Foot-and-mouth disease virus (FMDV) is one of the most economically serious veterinary pathogens due to its negative effects on livestock and its highly infectious nature via a variety of transmission paths through oral and inhalation routes. Measures to enhance outbreak management can be designed according to analytical results predicted by mathematical models for wind-borne dispersion, an important path of virus transmission. Accurate atmospheric dispersion models are useful tools for properly determining risk management plans, while inaccurate models may conversely lead to accidental loss in two possible ways. Overly strict measures, e.g., slaughter for too wide an area, can cause severe economic difficulties, including irreversible loss of business operations for a number of farms. On the contrary, inestimable loss potentially caused by lax controls is a persistent threat. In this paper, available modelling procedures for forecasting the spread of FMDV, which have been used since the 1970s, each having its advantages and limitations, are reviewed for the purpose of ensuring suitable application in various conditions of any future emergency cases.

Assessment of immunization procedures for foot-and-mouth disease in large-scale pig farms in China based on actual data and dynamics

Foot-and-mouth disease(FMD)is an acute,highly infectious and pathogenic animal disease.In recent years,with the rapid development of the swine breeding industry in China,pig farms have shown a trend of larger-scale development.Large-scale pig farms employ standardized management,a high level of automation,and a strict_system.However,these farms have a large trading volume,and increased transmission intensity of FMD is noted inside the farm.At present,the main control measure against FMD is pig vaccination.However,a standard for immunization procedures is not available,and currently adopted immunization procedures have not been effectively and systematically evaluated.Taking a typical large-scale pig farm in China as the research subject and considering the breeding pattern,piggery structure,age structure and immunization procedures,an individual-based state probability model is established to evaluate the effectiveness of the immune procedure.Based on numerical simulation,it is concluded that the optimal immunization program involves primary immunization at 40 days of age and secondary immunization at 80 days of age for commercial pigs.Breeding boars and breeding sows are immunized 4 times a year,and reserve pigs are immunized at 169 and 259 days of age.According to the theoretical analysis,the average control reproduction number of individuals under the optimal immunization procedure in the farm is 0.4927.In the absence of immunization,the average is 1.7498,indicating that the epidemic cannot be controlled without immunization procedures.

Eukaryotic Expression and Activity Analysis of Capsid Gene of Swine Vesicular Disease Virus HK/70

The capsid protein precursor （P1）, which plays a major role for the generation of polypeptides of swine vesicular disease virus （SVDV）, was cloned from SVDV HK/70 strain into the retroviral vector pBABE puro and expressed in the mammalian cell line PK15 through the retroviral expression system. The activity of recombinant protein to induce immune response was evaluated in guinea pigs. IFA and Western Blot were used to detect the recombinant protein expression. The results showed that the recombinant protein could be recognized by SVDV positive serum, and animal test showed SVDV-specific antibodies. All of those results indicate that a retroviral-based vaccine carrying the capsid protein precursor （P1） of SVD is able to be expressed in the eukaryotic cell and elicites strong SVDV-specific immune responses in guinea pigs.

Development and Preliminary Application of Double Antibody Sandwich ELISA for Detection of Swine Vesicular Disease Virus

[Objective] The aim of this study was to develop an indirect sandwich EUSA method for detection of swine vesicular disease virus （SVDV）. [Method] High titer serum against SVDV was prepared respectively by inoculated rabbits and guinea pigs with purified virus. To develop an indirect sandwich ELISA, the optimum concentrations of capture antibody, detection antibody, enzyme conjugate and standard antigen were determined using block titration, and positive threshold value was also determined. The specificity, sensitivity and repeatability of the developed IELISA were evaluated using cross-reaction test, comparison test and intra-assay repeated test. In addition, standard samples and clinical samples were detected by this method. [ Result] The best working conditions of the developed ELISA are as follows： capture antibody, 1：400; detection antibody, 1 ： 200; enzyme conjugate, 1 ： 8 000; and standard antigen, 1 ： 4. The positive threshold value was found to be 0.20. For the detection by the developed EUSA, no cross-reaction with foot and mouth disease was observed. The developed ELISA had close sensitivity with ELISA recommended by the World Organisation for Animal Health （OIE） but had sensitivity 2 -4 times higher than that of reverse indirect hernagglutination test. In addition, the developed method also had good reproducibility, and the detection results of standard samples were in line withtheir own background. All the 36 clinical samples were negative in the developed ELISA. [ Conclusion] The developed indirect sandwich ELISA can be used for diagnosis of swine vesicular disease.

Serological Investigation of Swine Reproductive Failure Diseases in Some Large-Scale Pig Farms in Henan Province

[ Objective] To investigate the prevalence situation of swine reproductive failure diseases in Henan Province and provide reference for the immunization and prevention of swine reproductive failure diseases. [ Method] Between May 2009 and April 2010, all serum samples from the Henan Agriculture University, Animal Disease Detection and Diagnosis Center were detected, including 6 825 serum samples for detecting classical swine fever （CSF） antibody, 2 609 for porcine reproductive and respiratory syndrome （PRRS） antibody, 1 177 for pseudorabies rabies virus gE （PRV） antibody, 123 for porcine parvovirus （PPV） antibody and 53 for chlamydiosis antibody. [ Result] The antibody positive rates of sere for de- tecting above five diseases were 63.28%, 61.44%, 25.49%, 39.84% and 5.66%, respectively. [ Conclusion] The immunization and prevention of CSF, PRRS, PPV and PR in Henan Province needs to be strengthened urgently, and the chlamvdiosis has been effectively controlled.

Preparation and Characterization of Monoclonal Antibodies against VP1 Protein of Foot-and-mouth Disease Virus O/China99

Monoclonal antibodies (McAbs) 1A9 and 9F12 against Foot-and-mouth disease virus (FMDV) serotype O were produced by fusing SP2/0 myeloma cells with splenocyte from the mouse immunized with O/China99. Both McAbs reacted with O/China99 but not with Asia 1, as determined by immunohistochemistry assay. The microneutralization titer of the McAbs 1A9 and 9F12 were 640 and 1 280, respectively. Both McAbs contain kappa light chains, but the McAbs 1A9 and 9F12 were IgG1 and IgM, respectively. In order to define the McAbs binding epitopes, the reactivity of these McAbs against VP1, P20 and P14 were examined using indirect ELISA, the result showed that both McAbs reacted with VP1 and P20. McAbs may be used for further studies of vaccine, diagnostic methods, prophylaxis, etiological and immunological researches on FMDV.

Generation of Monoclonal Antibodies against Non-structural Protein 3AB of Foot-and-Mouth Disease Virus

To identify linear epitopes on the non-structural protein 3AB of foot-and-mouth disease virus （FMDV）, BABL/c mice were immunized with the 3AB protein and splenocytes of BALB/c mice were fused with myeloma Sp2/0 cells. Two hybridoma monoclonal antibodies （mAbs） cell lines against the 3AB protein of foot-and-mouth disease virus （FMDV） were obtained, named C6 and E7 respectively. The mieroneutralization titer was 1：1024 for mAb C6, and 1：512 for E7. Both mAbs contain kappa light chains, and were of subclass IgG2b. In order to define the mAbs binding epitopes, the reactivity of these mAbs against FMDV were examined by indirect ELISA. The results showed that both mAbs can react with FMDV, but had no cross-reactivity with Swine Vesicular Disease （SVD） antigens. The titers in abdomen liquor were 1：5×10^6 for C6 and 1：2×10^6 for E7. In conclusion, the mAbs obtained from this study are specific for the detection of FMDV, can be used for etiological and immunological researches on FMDV, and have potential use in diagnosis and future vaccine designs.