Foot-and-mouth disease virus: DNA aptamer selection for the 3ABC protein

Foot-and-mouth disease: genomic and proteomic structure, antigenic sites, serotype relationships, immune evasion, recent vaccine development strategies, and future perspectives

Foot-and-mouth disease (FMD) is a highly contagious and transmissible disease that can have significant economic and trade repercussions during outbreaks. In Egypt, despite efforts to mitigate FMD through mandatory immunization, the disease continues to pose a threat due to the high genetic variability and quasi-species nature of the FMD virus (FMDV). Vaccines have been crucial in preventing and managing FMD, and ongoing research focusses on developing next-generation vaccines that could provide universal protection against all FMDV serotypes. This review thoroughly examines the genetic structure of FMDV, including its polyprotein cleavage process and the roles of its structural and non-structural proteins in immune evasion. Additionally, it explores topics such as antigenic sites, specific mutations, and serotype relationships from Egypt and Ethiopia, as well as the structural changes in FMDV serotypes for vaccine development. The review also addresses the challenges associated with creating effective vaccines for controlling FMD, particularly focusing on the epitope-based vaccine. Overall, this review offers valuable insights for researchers seeking to develop effective strategies and vaccines for controlling FMD.

Aptamer-Based Detection of Foot-and-Mouth Disease Virus Using Single-Stranded DNA Probe

Foot-and-mouth disease (FMD) is known for its highly contagious properties among cloven-hoofed animals resulting in significant morbidity rates. Incursions of this disease have caused significant losses in affected countries in Southeast Asia and Africa, even within EU countries which resulted in significant financial losses. This study is aimed at addressing existing limitations by creating a diagnostic method using aptamer-based assay. Three DNA aptamers were engineered to target the VP2 region of the FMD viral capsid protein. Since VP2 demonstrates a highly conserved amino acid sequence across serotypes, the specifically designed aptamers can detect different serotypes of the virus. Aptamers were evaluated against VP2 capsid protein, which was synthesized based on sequences from serotypes A, O, and Asia 1 of the FMD virus. After the recombinant VP2 capsid protein was developed, expressed, and refined, it was applied using enzyme-linked aptamer sorbent assay (ELASA) to determine aptamers' binding capability. A similar test was further conducted with purified FMD virus from serotype A and serotype O. The ELASA results displayed a notable sensitivity in identifying the FMDV. Under optimized conditions, the aptamers have LOD as low as 0.11 ng/mL with LOQ as low as 0.34 ng/mL. The binding strength analyzed using the equilibrium dissociation constant (Kd) showed strong binding affinity at 3.092 ± 0.05 nM. Based on these findings, the method shows significant potential with high sensitivity and specificity for FMD virus detection assay.

An insight into G-quadruplexes: Identification and potential therapeutic targets in livestock viruses

G-quadruplexes (G4s) are non-canonical nucleic acids secondary structures that involve in the regulation of some key biological processes, such as replication, transcription, and translation. G4s have been extensively described in the genomes of human and related diseases. In recent years, G4s were identified in several livestock viruses, including those of the emerging epidemics, like Nipah virus (NiV). Since their discovery, G4s have been developed as the potential antiviral targets, and the employment of G4 ligands or interacting proteins has helped to expound the viral infectivity and pathogenesis through G4-mediated mechanisms, and highlight the potential as therapeutic approaches. However, the comprehensively studies of G4s in livestock viruses have not been summarized. This review delves into the reported literatures of G4s in livestock viruses, particular focus on the presence, biophysical identification, and possible function of G4s in viral genome, summarizing the G4 ligands, interacted proteins and aptamers on antiviral applications. The strengths and the challenges of G4 targeting in this field are also discussed. Therefore, this review will shed new light on the future development of highly potent and targeting antiviral therapy.

Design and application of microfluidics in aptamer SELEX and Aptasensors

Aptamers are excellent recognition molecules obtained from systematic evolution of ligands by exponential enrichment (SELEX) that have been extensively researched for constructing aptasensors. However, in the process from SELEX to the construction of aptasensors, there are many disadvantages, such as tedious and repetitive operations, interference from external factors, and low efficiency, which seriously limits their application scope and development. Introducing the microfluidic technology can realize the integration and intelligence of SELEX and aptasensing, improve the efficiency of SELEX, and enhance the detection performance and convenience of aptasensing. Hence, in this review, the characteristics of various chips based on different driving forces are described firstly. And then summarizing the design of microfluidic devices based on different SELEX methods and showing the strategies of microfluidic aptasensors based on different detection modes. Finally, discussing the difficulties and challenges encountered when microfluidic is integrated with the SELEX and the aptasensors.

A review of foot-and-mouth disease in Ethiopia: epidemiological aspects, economic implications, and control strategies

Foot-and-mouth disease (FMD) is a contagious viral disease that affects the livelihoods and productivity of livestock farmers in endemic regions. It can infect various domestic and wild animals with cloven hooves and is caused by a virus belonging to the genus Aphthovirus and family Picornaviridae, which has seven different serotypes: A, O, C, SAT1, SAT2, SAT3, and Asia-1. This paper aims to provide a comprehensive overview of the molecular epidemiology, economic impact, diagnosis, and control measures of FMD in Ethiopia in comparison with the global situation. The genetic and antigenic diversity of FMD viruses requires a thorough understanding for developing and applying effective control strategies in endemic areas. FMD has direct and indirect economic consequences on animal production. In Ethiopia, FMD outbreaks have led to millions of USD losses due to the restriction or rejection of livestock products in the international market. Therefore, in endemic areas, disease control depends on vaccinations to prevent animals from developing clinical disease. However, in Ethiopia, due to the presence of diverse antigenic serotypes of FMD viruses, regular and extensive molecular investigation of new field isolates is necessary to perform vaccine-matching studies to evaluate the protective potential of the vaccine strain in the country.