Foot-and-mouth Disease Type Research Articles

The role of zinc sulfate in enhancing cellular and humoral immune responses to foot-and-mouth disease vaccine

Foot-and-mouth disease (FMD) is a rapidly propagating infectious disease of cloven-hoofed animals, especially cattle and pigs, affecting the productivity and profitability of the livestock industry. Presently, FMD is controlled and prevented using vaccines; however, conventional FMD vaccines have several disadvantages, including short vaccine efficacy, low antibody titers, and safety issues in pigs, indicating the need for further studies. Here, we evaluated the efficacy of a novel bivalent vaccine containing zinc sulfate as an immunostimulant and FMD type O and A antigens (O PA2 and A YC, respectively) against FMD virus in mice and pigs. Zinc sulfate induced cellular immunity in murine peritoneal exudate cells (PECs) and porcine peripheral blood mononuclear cells (PBMCs) by increasing IFNγ secretion. Additionally, FMD vaccine containing O PA2 and A YC antigens and zinc sulfate induced early, mid-, and long-term immune responses in mice and pigs, and enhanced cellular and humoral immunity by regulating the expression of pathogen recognition receptors (PRRs), transcription factors, co-stimulatory molecules, and cytokines in porcine PBMCs from vaccinated pigs. Overall, these results indicated that the novel immunostimulant zinc sulfate induced potent cellular and humoral immune responses by stimulating antigen-presenting cells (APCs) and T and B cells, and enhanced long-term immunity by promoting the expression of co-stimulatory molecules. These outcomes suggest that zinc sulfate could be used as a novel vaccine immunostimulant for difficult-to-control viral diseases, such as African swine fever (ASF) or COVID-19.

Evaluation of Immunogenicity of Clostridium perfringens Type B Toxoid and Inactivated FMD (O) Virus with Adjuvant (ISA70-MF59).

Foot and mouth disease (FMD) and enterotoxemia are important diseases of hoofed animals. Vaccination against livestock pathogens, especially these two diseases, plays a key role in the prevention and control of these diseases. The use of combined vaccines with the aim of creating a better immune response and producing cheaper vaccines is a great contribution to Vaccine industry. This research aimed to compare the immunogenicity of FMD (O) and Clostridium perfringens type B toxoid along with adjuvant (MF59) and Montanide (ISA70) to create the best immunogenicity. To investigate the immune responses of vaccines, it was injected into an animal model, and the antibody titer was measured by enzyme-linked immunosorbent assay (ELISA) test and VN antibody titer. The results showed that the formulation with MF59 adjuvant brought more stable immunogenicity against FMD and Clostridium perfringens type B, and the length of the immunogenicity period also increased significantly. Therefore, the combined vaccine (Clostridium perfringens + FMD) could play a major role invaccine industry as an alternative vaccine against Clostridium perfringens and FMD in livestock.

Immunogenicity and Protection against Foot-and-Mouth Disease Virus in Swine Intradermally Vaccinated with a Bivalent Vaccine of Foot-and-Mouth Disease Virus Type O and A.

Following the worst outbreak of foot-and-mouth disease (FMD), a highly contagious disease in cloven-hoofed animals caused by the FMD virus, from November 2010-April 2011, the Korean government enforced a mandatory vaccination policy. A bivalent (FMD type O and A; O + A) vaccine has been recently implemented. Although the FMD outbreak was suppressed by vaccination, the intramuscular (IM) injection presents side effects. Therefore, improving FMD vaccine quality is necessary. Here, we investigated the side effects and immune efficacy of the O + A bivalent vaccine using two different routes of administration: intradermal (ID) and IM. To compare the immune efficacy of the two inoculation routes, virus neutralization titers and structural protein (antigen) levels were measured. The protective efficacy of ID vaccines was confirmed using two viruses (FMDV O/AS/SKR/2019 and A/GP/SKR/2018) isolated in the Republic of Korea. Serological analysis revealed that both animals administered by ID and IM injections exhibited equal immune efficacy. A virus challenge test in the target animal (swine) revealed no (or extremely low) clinical symptoms. Swine in the ID injected group exhibited no side effects. In conclusion, we suggest that the ID route of vaccination is an effective alternative to the existing IM route, which is associated with more frequent side effects.

Evaluation of Vaccine Strains Developed for Efficient, Broad-Range Protection against Foot-and-Mouth Disease Type O.

Foot-and-mouth disease (FMD) type O includes 11 genetic topotypes. The Southeast Asia (SEA), Middle East-South Asia (ME-SA), and Cathay topotypes belong to FMD type O and occur frequently in Asia. Therefore, it is necessary to develop a potent vaccine strain with a broad antigenic coverage in order to provide complete protection against these three topotypes. In this study, an experimental vaccine was produced using chimeric vaccine strains (JC-VP1 or PA2-VP1) that contained VP4, VP2, and VP3 of the ME-SA topotype (O Manisa) and VP1 of the SEA topotype (Mya98 lineage; O/SKR/Jincheon/2014) or ME-SA topotype (PanAsia2 lineage; O/PAK/44). Mice were immunized with the experimental vaccines, and they were fully protected against the three topotypes. The neutralizing antibody titers of PA2-VP1 were significantly higher than those of JC-VP1 in the early vaccination phase in pigs. Here, we confirmed complete protection in pigs vaccinated with JC-VP1 or PA2-VP1, when challenged against the SEA (O/SKR/Jincheon/2014), ME-SA (O/SKR/Boeun/2017) and Cathay (O/Taiwan/97) topotype viruses, with moderately higher protection provided by PA2-VP1 than by JC-VP1.

A Report on Massive Outbreaks of FMD with Concurrent Mannhaemia hemolytica Infection among Cattle in Tamil Nadu

Back ground: India has a huge resource of livestock and stands first globally in milk production, but reemergence of diseases like foot and mouth disease (FMD) causes a great concern and economic losses to the farmers. Three serotypes of FMD virus (O, A and Asia 1) are prevalent and serotype O was responsible for 80 per cent of confirmed outbreaks /cases in India. The highest incidence of the disease was seen in Southern region (31.5%) and during the month of September. Highest number of outbreaks (201) occurred in Tamil Nadu in the year 2007-08 caused by serotype O virus. FMD causes very high morbidity and mortality rate among young animals and the mortality rate is generally low in adult animals and seen with manifestation of infection limited to epithelial sites. However, In the present study an unusually high mortality among adult cattle due to FMD, complicated with Mannheimia hemolytica infection with specific myocardial lesions were discussed in several outbreaks of FMD in the state of Tamil Nadu, India. Methods: Outbreaks of FMD occurred in various districts of Tamil Nadu during the period of October to December in the year 2013 causing large scale mortality among adult cross bred (Jersey cross and Holstein Friesian cross) cows, heifers and calves and detailed disease investigations were carried out .Samples were collected from ailing animals and dead animals for laboratory confirmation of the disease. The collected samples were subjected to isolation of bacteria, serology and molecular confirmation of the virus. Result:Affected animals showed characteristic lesions of FMD with multiple, focal to coalescing ulcers and erosions covered with shreds of epithelium and fibrin on the dorsum and lateral margins of the tongue, dental pad, hard palate, mucosa of lips and gums. Samples of vesicular fluid, oral and tongue epithelium and heart confirmed the presence of FMD type ‘O’ virus based on sandwich ELISA and multiplex PCR. Cultural examination of bacteriological samples revealed presence of Mannheimia hemolytica which was further confirmed by multiplex PCR. Out of 83 serum sample collected, 45 sera were positive for FMD by LPB ELISA, while 32 serum samples were positive for FMD by DIVA test. The sudden deaths among adult cattle and heifers during the FMD outbreak might be attributed to the severe myocarditis and the disease was controlled by following appropriate treatment and preventive measures.

Dietary Astragalus membranaceus and Codonopsis pilosula extracts mixture supplementation increases the growth performance and foot-and mouth disease antibody titers in growing-finishing pigs

An experiment was conducted to evaluate the effects of herbal extract mixture (HEM, Astragalus membranaceus and Codonopsis pilosula) supplementation on growth performance, nutrient digestibility, and foot-and mouth disease (FMD) antibody titers in growing-finishing pigs. A total of 120 FMD type O vaccinated growing pigs ([Yorkshire × Landrace] × Duroc) with an average initial body weight (BW) of 25.19 ± 1.80 kg were randomly allotted into 3 treatments with 8 replicate of 5 pigs per pen for a 16-week feeding trial. All pigs were vaccinated against FMD. Treatments consisted of CON, Corn-soybean meal based basal diet; TRT1, CON + 0.5 g kg−1 HEM; TRT2, CON + 1g kg−1 HEM. Pigs fed with 1g kg−1of HEM showed higher (P< 0.05) BW and ADG on week 12, 16, and overall period. Herbal extract mixture supplementation at the dose of 1g kg−1showed higher FMD type O antibody titers (P< 0.05) at week 14 compared with non-supplemented group. Theseresults indicated that HEM supplementation at 1g kg−1dose may confer anti-viral effect against FMD thereby improving the average daily gain of the growing-finishing pigs. Herbal extract mixturemay potentially be used as an anti-viral agent to help increase FMDV type O antibody titer after vaccination.

Development of Monoclonal Antibody Specific to Foot-and-Mouth Disease Virus Type A for Serodiagnosis.

Foot-and-mouth disease (FMD) is a highly contagious and economically devastating disease affecting cloven-hoofed livestock worldwide. FMD virus (FMDV) type A is one of the most common causes of FMD outbreaks among the seven FMDV serotypes, and its serological diagnosis is therefore important to confirm FMDV type A infection and to determine FMD vaccine efficacy. Here, we generated monoclonal antibodies (mAbs) specific to FMDV type A via hybridoma systems using an inactivated FMDV type A (A22/Iraq/1964) and found 4 monoclones (#29, #106, #108, and #109) with high binding reactivity to FMDV type A among 594 primary clones. In particular, the #106 mAb had a higher binding reactivity to the inactivated FMDV type A than the other mAbs and a commercial mAb. Moreover, the #106 mAb showed no cross-reactivity to inactivated FMDV type South African territories 1, 2, and 3, and low reactivity to inactivated FMDV type O (O1 Manisa). Importantly, the solid-phase competitive ELISA (SPCE) using horseradish peroxidase (HRP)-conjugated #106 mAb detected FMDV type A-specific Abs in sera from FMD type A-vaccinated cattle more effectively than a commercial SPCE. These results suggest that the newly developed FMDV type A-specific mAb might be useful for diagnostic approaches for detecting Abs against FMDV type A.

Evaluation of cytokine mRNA expression in vaccinated guinea pigs with foot-and-mouth disease type O inactivated vaccine

Foot-and-mouth disease (FMD) is a severely contagious viral disease that mainly affects cloven-hoofed livestock and wildlife. This study quantifies the cytokines mRNA expression of vaccinated guinea pigs with FMD type O inactivated vaccine. Blood samples were collected from eight guinea pigs at 7 and 28 days after the first vaccination. Extracted mRNAs were reverse-transcribed into cDNA and analyzed for quantification of IFNγ, TNF-α and IL-10 expression using relative real-time PCR assay. Our results showed that all of the genes were upregulated. The expression of TNF-α and IL-10 genes significantly increased (P<0.05) in day 28th in comparison to the day 7th post the first vaccination. It can be concluded that the vaccine induced immune responses by increasing expression of the cytokines. Therefore, effects of DNA vaccines on immune system also may be evaluated using these genes.

Virological and immunological studies on foot and mouth disease virus type SAT2 naturally infected and vaccinated buffalo cows and their calves

Aim: Due to inadequate data on the dynamics of foot and mouth disease (FMD) infection in buffalo, the present work was aimed at investigating some virological and immunological aspects of FMD virus (FMDV) SAT2 infection in naturally exposed and vaccinated buffalo cows and their calves. Materials and Methods: The study employed clinical observation and examination, virus isolation in mice brain and cell culture, in addition to virus detection using complement fixation test; indirect sandwitch enzyme-linked immunosorbent assay and demonstration of RNA by reverse transcription polymerase chain reaction for confirmation the results. Results: FMD type SAT2 antibodies was detected in a protective level by the 1 st week post infection and 3 rd week post vaccination and peak titers were recorded by the 3 rd week, 12 th week in infected and vaccinated buffaloes, respectively. These titers began to decline to reach their lowest protective levels by the 36 th week, 12 nd week in infected and vaccinated buffaloes respectively. The SAT2 antibodies in calves born to vaccinated and infected buffalo cows were detected on the 1 st day post parturation through the suckling of their Dam’s colostrums. The highest maternal antibody titers were recorded in sera by the 2 nd day post parturation. These antibodies declined gradually to reach their lowest protective levels on14 th week, 16 th week post parturition in calves rom vaccinated and infected buffaloes, respectively. High antibody titers in the colostrums and milk of vaccinated and naturally infected buffalo cows were recorded at parturition, and they began to decrease gradually recording their lowest protective titers by 10 th and 12 nd week post parturition respectively. Conclusion: FMDV serotype SAT2 was confirmed as a causative agent of the suspected FMD signs in pregnant buffalo at El-Fayoum Governorate, Egypt, during 2012. Vaccinated and naturally infected buffalo cows were able to provide their calves with high levels of maternal derived antibodies through their colostrums, which could protect new born calves for not less than 14 week post parturation.

Phylogenic Analysis and Molecular Characterization of Slemani/Kurdistan/2013 Foot and Mouth Disease Virus Shows Circulation of New Genotype in Iraq

Foot-and-mouth disease (FMD) is endemic in Iraq. There were no much informations&#x0D; about FMD genotypes in Iraq. In this study, FMD type A virus was identified by RT-PCR from&#x0D; a cow in Kurdistan region. Viral protein1 (VP1) was amplified, sequenced and published in&#x0D; National Center for Biotechnology Information (NCBI) GenBank as Slemani/Kurdistan/2013.&#x0D; VP1 nucleic acid and amino acid sequence of Slemani/Kurdistan/2013 was comparatively&#x0D; analysed with all previously published Iraqi FMDV type A sequences available in NCBI Gen&#x0D; Bank from 1964 to 2013. The result indicated that Slemani/Kurdistan/2013 had 10 amino acid&#x0D; residues in immunogenic VP1 region, which were not present in other Iraqi FMD isolates.&#x0D; Furthermore, sequence alignment of Slemani/Kurdistan/2013 showed the amino acid identity&#x0D; ranged from 83 % to 93%, and the nucleotide identity ranged from 69% to 93% with other&#x0D; Iraqi FMDV type A isolates. Phylogenetic tree analysis showed that the identified field isolate&#x0D; differed from the other Iraqi subtype and could be placed in distinct sub lineages. It can be&#x0D; concluded that new genotype was circulated in Iraq. Therefore, monitoring the emergence of&#x0D; new FMDV strains in Iraq is important to enable appropriate vaccines selection.

Phylogenetic analysis of Foot-and-Mouth Disease Virus type O circulating in the Andean region of South America during 2002–2008

At present, Foot-and-Mouth Disease (FMD) has been successfully controlled in most territories of South America, where only Ecuador and Venezuela remain as endemic countries. In this context, the precise characterization of circulating viruses is of utmost importance. This work describes the first molecular epidemiology study performed with the complete VP 1-coding region of 114 field isolates of FMD virus (FMDV) type O, collected in the Andean countries mainly during 2002–2008. Sequences were aligned and compared to isolates responsible for emergencies in the Southern Cone of the continent between the years 2000 and 2006, and to other representative type O viruses worldwide. The results showed that FMD type O viruses isolated in South America and analyzed up to date are placed in 11 different lineages within the Euro SA topotype. Five of these lineages included viruses circulating in Ecuador and Venezuela during 2002–2008. The last emergencies reported in already-free areas in the Andean region, showed close relationships with viruses circulating in these endemic countries. Andean lineages showed a clear separation from the unique lineage containing viruses responsible for the emergencies in the Southern Cone, reflecting the different livestock circuits and providing evidence that support the ecosystem dynamics in the region. A wide geographical dissemination of the same strain in short time intervals has been observed, pointing to animal movements as the most significant risk parameter. This fact, together with an important generation of viral variants in areas under weak control strategies, reinforce the need of stronger official controls, as well as for establishing multinational cooperative measures in the border areas.

Improvement of a commercial foot-and-mouth disease vaccine by supplement of Quil A

In model animal experiment A, ICR mice were immunized with ovalbumin (OVA) adjuvanted with Quil A or mineral oil or their combination (Quil A+oil). In model animal experiment B, ICR mice were immunized with foot-and-mouth disease virus (FMDV) antigens or with a commercially available oil adjuvanted foot-and-mouth disease (FMD) vaccine (type O) alone or mixed with Quil A. After that, serum samples were collected to analyze specific IgG and IgG subclasses IgG1, IgG2a, IgG2b, and IgG3. In experiment C, pigs were immunized with FMD (type O) vaccine alone or together with Quil A. Serum samples were collected before and 4 weeks after immunization to analyze indirect haemagglutination (IHA) titers. Results from experiment A indicated a synergistic effect of Quil A and oil on IgG and the subclass responses. Experiment B revealed that supplement of Quil A in FMD vaccine significantly increased IgG and the subclass responses in mice. Experiment C demonstrated that supplement of Quil A in the FMD vaccine significantly enhanced humeral immune responses (as determined by IHA test) in pigs. It is concluded that supplement of Quil A in FMD vaccine can significantly enhanced immune responses and could be an alternative way to improve FMD vaccination in pigs.

Development of novel strategies to control foot-and-mouth disease: Marker vaccines and antivirals

Foot-and-mouth disease (FMD) is economically the most important viral-induced livestock disease worldwide. The disease is highly contagious and FMD virus (FMDV) replicates and spreads extremely rapidly. Outbreaks in previously FMD-free countries, including Taiwan, the United Kingdom, and Uruguay, and the potential use of FMDV by terrorist groups have demonstrated the vulnerability of countries and the need to develop control strategies that can rapidly inhibit or limit disease spread. The current vaccine, an inactivated whole virus preparation, has a number of limitations for use in outbreaks in disease-free countries. We have developed an alternative approach using a genetically engineered FMD subunit vaccine that only contains the portions of the viral genome required for virus capsid assembly and lacks the coding region for most of the viral nonstructural (NS) proteins including the highly immunogenic 3D protein. Thus, animals inoculated with this marker vaccine can readily be differentiated from infected animals using diagnostic assays employing the NS proteins not present in the vaccine and production of this vaccine, which does not contain infectious FMDV, does not require expensive high-containment manufacturing facilities. One inoculation of this subunit vaccine delivered in a replication-defective human adenovirus vector can induce rapid, within 7 days, and relatively long-lasting protection in swine. Similarly cattle inoculated with one dose of this recombinant vector are rapidly protected from direct and contact exposure to virulent virus. Furthermore, cattle given two doses of this vaccine developed high levels of FMDV-specific neutralizing antibodies, but did not develop antibodies against viral NS proteins demonstrating the ability of FMD subunit vaccinated animals to be differentiated from infected animals. To stimulate early protection prior to the vaccine-induced adaptive immune response we inoculated swine with the antiviral agent, type I interferon, and induced complete protection within 1 day. Protection can last for 3–5 days. The combination of the FMD marker vaccine and type I interferon can induce immediate, within 1 day, and long-lasting protection against FMD. Thus, this combination approach successfully addresses a number of concerns of FMD-free countries with the current disease control plan. By rapidly limiting virus replication and spread this strategy may reduce the number of animals that need to be slaughtered during an outbreak.

Traceback systems used during recent epizootics in Asia

Traceback systems in most countries of Asia are not well developed, as indicated by responses to a questionnaire by veterinary officials in thirteen countries. Marking of animals for traceback is practised only in a limited number of countries in specific areas or zones and for specific purposes only. In Malaysia, traceback has been undertaken by marking farm code tattoos on pigs. This enables the identification of the farm of origin of pigs found to be infected by Nipah virus in sero-surveillance programmes. The origin of the foot and mouth disease (FMD) virus that surfaced in the Republic of Korea in March 2000 was investigated through several epidemiological studies of suspected sources of contamination such as imported hay, yellow sand, milk collection trucks and feed delivery trucks. None of these studies gave results that indicated the origin of the FMD virus. The origin of the FMD virus that was recorded in Japan in March 2000 was also investigated in epidemiological studies; in this case, imported wheat straw was incriminated as the most likely source of infection. Comparative studies of the pathogenicities of FMD (type O) viruses isolated in Taipei China, the Republic of Korea and Japan, suggest that these viruses might have originated as vaccine strains used in a third country.

Foot-and-mouth disease type O viruses exhibit genetically and geographically distinct evolutionary lineages (topotypes).

Serotype O is the most prevalent of the seven serotypes of foot-and-mouth disease (FMD) virus and occurs in many parts of the world. The UPGMA method was used to construct a phylogenetic tree based on nucleotide sequences at the 3' end of the VP1 gene from 105 FMD type O viruses obtained from samples submitted to the OIE/FAO World Reference Laboratory for FMD. This analysis identified eight major genotypes when a value of 15% nucleotide difference was used as a cut-off. The validity of these groupings was tested on the complete VP1 gene sequences of 23 of these viruses by bootstrap resampling and construction of a neighbour-joining tree. These eight genetic lineages fell within geographical boundaries and we have used the term topotype to describe them. Using a large sequence database, the distribution of viruses belonging to each of the eight topotypes has been determined. These phylogenetically based epidemiological studies have also been used to identify viruses that have transgressed their normal ecological niches. Despite the high rate of mutation during replication of the FMD virus genome, the topotypes appear to represent evolutionary cul-de-sacs.

Phylogenetic analysis of foot-and-mouth disease viruses isolated in Argentina.

We have analysed complete or partial VPI sequences of 31 foot-and-mouth disease (FMD) viruses belonging to serotypes A, O and C to determine the genetic relatedness of field strains of FMD virus (FMDV) that have circulated in Argentina between 1961 and 1994. Phylogenetic analysis, which also included 15 previously published Argentinean sequences and six reference strains, revealed that (i) FMD type A strains showed the highest genetic heterogeneity and could be divided into five lineages with a sequence divergence of 0.9-18.5% between strains (ii) most of the FMD type O viruses grouped in two clusters (within cluster sequence divergence ranging from 0.2% to 6.0%) circulating in Argentina since the early 1960s, and (iii) FMD type C viruses were grouped in two clusters with a 13.4% nucleotide sequence divergence between each cluster. The availability of sequence data for many more field isolates from the region will enable us to understand the genetic relationships between FMDV strains and to rapidly trace the source of an FMD outbreak for epidemiological surveillance.

Detection and Subtyping of Foot-and-Mouth Disease Virus in Infected Cattle by Polymerase chain Reaction and Amplified VP1 Sequencing

Fast and accurate detection of foot-and-mouth disease (FMD) outbreaks is needed to limit spread of the disease by proper vaccination. The use of the polymerase chain reaction (PCR) has revolutionized the way in which viral diseases are diagnosed. Sequence analysis of the amplified VP1 sequence can enable the classification of FMD virus detected in the morbid animal. PCR assays were carried out to identify the virus and its serotype in suspect animals from 2 outbreaks of FMD type O virus. Sequence analysis of the amplified VP1 cDNA showed 78% homology with O1K and over 95% homology between the samples. These findings suggest that the 2 outbreaks were due to infection with the same virus serosubtype.

Natural transmission of foot-and-mouth disease virus from African buffalo (Syncerus caffer) to cattle in a wildlife area of Zimbabwe

An outbreak of foot-and-mouth disease (FMD) occurred during April 1991 in a trypanosomiasis sentinel cattle herd by the Rifa River to the east of Lake Kariba, Zimbabwe. Despite the cattle having been vaccinated biannually for the previous five years the disease was severe. The viruses isolated from the affected animals were typed as FMD virus type SAT 1. Free-living African buffalo (Syncerus caffer) which had been using the same watering place as the affected cattle were sampled and FMD type SAT 1 virus was isolated. Partial nucleotide sequencing of the gene coding for the capsid protein 1D (VP1) of one of the viruses isolated from cattle and two of the viruses isolated from buffalo demonstrated a close relationship between the three viruses. Since no other cattle were present in the area and no outbreaks of SAT 1 had occurred in Zimbabwe since 1989, it was concluded that the disease had been transmitted from buffalo to cattle.