Veterinary Research Forum

Abstract Foot-and-mouth disease virus (FMDV) continues to pose a major threat to the livestock industry worldwide due to its high transmissibility and substantial economic consequences. For diagnostic and vaccinal purposes, necessitate the exploration of novel immunogenic targets is pivotal. Here, antigenic determinant (an epitope) sequence comprising core of 12 amino acids from VP1 protein of foot-and-mouth disease virus (FMDV) was designed by immuno informatics. To improve the physio-chemical and stability characteristics of the final peptide, additional residues were incorporated until it resulted in the synthesis of a 23-amino acid peptide (VARTLPTSFNYGAIKATRVTDEC, 2.5 Kda and PI 8.17). After chemical synthetizing with 95 % purity, the peptide was conjugated to bovine serum albumin (BSA) via EDC/NHS cross linker (Peptide: EDC: Sulfo-NHS: BSA (carrier protein): 10:40:50:1 in MES buffer (50 Mm)) and formulated with an aluminum hydroxide adjuvant. Twelve male New Zealand White rabbits were randomly assigned into three groups and main group received the peptide-BSA conjugate. Sera were direct to Dot blot, double immunodiffusion (DID) and serum neutralization (SN) tests, and also indirect peptide ELISA. The synthetic peptide elicited strong antibody response by primary positive results in dot blot and DID test (positive in 1:4 serum dilution) as well as it showed cross-reactivity with whole antigen. Although only low SN titers (1:8) were observed. Moreover, the peptide ELISA confirmed specific antibody responses against O serotype (OD of 2.4 at day 55 in 1/10 dilutions). Altogether, rationally designed epitope are promising regimes for the future development of FMDV novel diagnostic tools and vaccine cocktails.

Abstract Foot-and-mouth disease virus (FMDV) is a highly transmissible pathogen causing severe economic losses in the global livestock sector. Frequent outbreaks of FMDV type-O in Pakistan highlight the need for continuous genomic and antigenic surveillance to track its evolution. This study aimed to isolate and molecularly characterize FMDV type-O from an outbreak in the Punjab province of Pakistan using in vitro cell culture techniques. Samples were processed for viral isolation on a susceptible cell line, followed by RNA extraction. The VP1 gene, pivotal for antigenicity and immunogenicity, was amplified using a one-step polymerase chain reaction protocol. Purified amplicons underwent sequencing, and the nucleotide sequences were translated into amino acid sequences for further analysis. Protein three-dimensional modeling and in silico comparison were performed against the vaccinal seed strain PanAsia-2. The VP1 sequence analysis revealed notable genetic variability among the isolates, indicating adaptive evolution. Structural and antigenic modeling uncovered key differences between the field isolates and vaccinal strain, suggesting potential antigenic drift, which could undermine vaccine performance. The study underscores the dynamic evolution of FMDV type-O in Pakistan and the critical importance of ongoing genomic monitoring to refine vaccine strategies and enhance outbreak control.

Abstract The aim of this study was to using purified chicken antibody (IgY) for developing solid phase competitive (SPC) enzyme-linked immunosorbent assay (ELISA) to detect the foot-and-mouth disease virus (FMDV) A serotype. After immunization of chickens, polyclonal immunoglobulin (IgY) antibodies were extracted and purified from egg yolk and yield was about 5.00 mg mL^-1 of yolk as well as near 0.40 mg mL^-1 of specific IgY antibody against FMDV serotype A. Also, optimized sucrose density gradient method produced 228 µg mL^-1 whole virus which is much higher than that of the conventional method of sucrose density gradient method. The optimum concentration of purified capture IgY and bind type A antigen were 0.50 µg and 0.10 µg per well, respectively. The OD values < 0.70 were considered positive, and values ≥ 0.70 were negative for in-house kit base on standard controls. Statistical analysis base on 80 serum samples showed the 96.66% sensitivity, 100% specificity, 100% positive predictive value, 90.90% negative predictive value, 97.50% accuracy, and 98.33% reliability for serum samples for two commercial and in-house kits. The SPCE developed based on IgY antibody is a suitable alternative for the detection of antibodies after vaccination against type A FMDV with high sensitivity and specificity. The present research demonstrated the possibility of commercial development of the SPCE kit using IgY antibodies for the detection of FMDV antibodies in serum samples with adequate sensitivity and accuracy.

Abstract Foot-and-mouth disease (FMD) is considered as one of the most important contagious viral diseases affecting cloven-footed animals. For effective control of FMD, immunization along with herd immunity is essential in the field conditions. To assure and track the coverage and effectiveness of the vaccination program, the serological studies are very much required after the vaccination program. The present study was aimed to investigate the prevalence of antibodies against structural proteins of FMD virus (FMDV) serotypes of O, A and Asia-1 in seven districts of western Uttar Pradesh, India, and assure the efficacy of vaccination under National Animal Disease Control Program. A total of 308 sera samples were collected from apparent healthy vaccinated cattle and buffaloes from seven districts including Amroha, Baghpat, Bareilly, Bulandsahar, Gautam Budh Nagar, Meerut and Muzaffarnagar of western Uttar Pradesh, India. Determination of antibodies against structural proteins of FMDV was carried out using solid-phase blocking enzyme-linked immunosorbent assay. The protective level of the FMDV serotypes O, A and Asia-1 included in the inactivated trivalent vaccine was 66.55, 48.05 and 47.08% in bovines, respectively. To provide the higher level of protection against the circulating FMDV, the present study recommended the thorough investigation of the immunogenic interaction between the vaccine strains and the field strains. Further investigations should also be conducted with larger sample size and across diverse geographical regions to gain a more comprehensive understanding of herd immunity.