Molecular epidemiology, evolution and phylogeny of foot-and-mouth disease virus

Abstract

Foot-and-mouth disease virus (FMDV) is responsible for one of the most economically important infectious diseases of livestock. The virus spreads very easily and continues to affect many countries (mainly in Africa and Asia). The risks associated with the introduction of FMDV result in major barriers to trade in animals and their products. Seven antigenically distinct forms of the virus are known, called serotypes, but serotype C has not been detected anywhere for many years and may now be extinct. The serotypes have been further divided into topotypes (except for serotype Asia-1 viruses, which comprise a single topotype), genotypes, lineages and sub-lineages, which are usually restricted to specific geographical regions. However, sometimes, trans-regional spread of some strains occurs. Due to the error-prone replication of the RNA genome, the virus continuously evolves and new strains frequently arise (e.g. with modified antigenicity). Using nucleotide sequencing technologies, this rapid evolution of the viral genome can be followed. This allows the tracing of virus transmission pathways within an outbreak of disease if (near) full-length genome sequences can be generated. Furthermore, the movement of distinct virus lineages, from one country to another can be analyzed. Some important examples of the spread of new strains of FMD virus are described.

Evidence for multiple recombination events within foot‐and‐mouth disease viruses circulating in West Eurasia

“…However, the higher evolutionary rate of about 1.2 × 10 –2 substitutions/nt/yr, calculated for the A‐Iran05 lineage, suggests that new sub‐lineages will evolve within a period of about three years (Jamal et al, ). This is indeed consistent with the existence of multiple sub‐lineages for the A‐Iran05 lineage (Jamal & Belsham, ).…”

“…However, the higher evolutionary rate of about 1.2 × 10 -2 substitutions/nt/yr, calculated for the A-Iran05 lineage, suggests that new sub-lineages will evolve within a period of about three years (Jamal et al, 2011a). This is indeed consistent with the existence of multiple sub-lineages for the A-Iran05 lineage (Jamal & Belsham, 2018 (King, 1988), and therefore, recombination that swaps VP4 sequences is expected to occur (and yield viable genomes) since the nucleotide sequences in this region of the genome are much more highly conserved among different FMDV serotypes than within the rest of the capsid coding region. Viability constraints are most likely to operate within the VP2-VP3-VP1 coding region.…”

“…This recombinant FMDV O‐PanAsia‐II ANT‐10 sub‐lineage was first detected in Pakistan in early 2009 (Brito et al, ) and has spread widely throughout West Eurasia and continues to be responsible for major FMD outbreaks in the region. It has also crossed its usual geographic boundaries and has caused outbreaks in Libya in 2010 and in the previously disease‐free European country, Bulgaria, in 2011 (see Jamal & Belsham, ; Valdazo‐Gonzalez et al, ). Recombination may play a role in the success of this sub‐lineage in terms of its degree of infectiousness by combining different determinants of virulence.…”

“…Foot‐and‐mouth disease virus (FMDV), the prototypic member of the genus Aphthovirus within the family Picornaviridae , is the causative agent of foot‐and‐mouth disease (FMD), an infectious and highly contagious disease of cloven‐hoofed animals (Jamal & Belsham, , ). FMDV particles consist of a single stranded positive‐sense RNA, about 8.4 kb in length, surrounded by a protein shell or capsid (Acharya et al, ).…”

Generation of monoclonal antibodies against foot‐and‐mouth disease virus SAT 2 and the development of a lateral flow strip test for virus detection

“…The FMDV serotypes O and A are the most widespread. Asia 1 is primarily found in Asia, periodically into the Middle East and occasionally in Europe (Valarcher et al, 2009;Brito, Rodriguez, Hammond, Pinto, & Perez, 2017;Jamal & Belsham, 2018). FMDV SAT 1, 2 and 3 are primarily restricted to Africa.…”