Animal enteroviruses: a glimpse of a wide evolutionary landscape

Abstract

The genus Enterovirus (family Picornaviridae) contains numerous viruses, most of which have been identified in humans. Among them, the three serotypes of poliovirus, coxsackieviruses A and B, echoviruses, rhinoviruses and other enteroviruses (EVs) responsible in humans for a wide spectrum of clinical manifestations. There are also 60 identified EVs in different mammals. Some have been found in both humans and animals, demonstrating the possibility of zoonotic transmission of certain EVs.Compared to human EVs, genetic and epidemiological data for animal EVs are scarce.However, the detection of EVs in various species of mammals and their presence on all continents suggest that the number of EVs still to be discovered is very important. Some EVs found in animals have characteristics never seen in human EVs. Furthermore, the unique phylogenetic relationships observed between animal EVs raise interesting questions about the rules that govern the evolution of these viruses. The aim of this review is to present the salient data on animal EVs and to highlight the questions they raise.

Characterization of enteroviruses circulating among farm animals and children in Central African Republic

“…Both sub-groups feature capsid-encoding sequences that remain genetically close together while their non-capsid regions segregate into two separate clusters, depending on their respective hosts. Similar observations were previously made within species EV-A and EV-B [ 4 ], of which some members that circulate among NHPs are closer to simian EVs of other EV species than to human EVAs or EV-Bs in the non-structural region of their genomes [ 30–32 ]. These data further demonstrate that the forces that drive the EV evolution are not evenly applied along their genome.…”

“…It is known that EV-G 5’UTR sequences fall into two distinct groups [ 4 ]. One group (group A in Figure 4 ) only contains sequences of EV-Gs and gathers all known EV-Gs from swine; the second one (group B in Figure 4 ) is composed of EV-G sequences that are phylogenetically and structurally close to the 5’UTRs of EV-Es and EV-Fs.…”

“…Since 2017, EV-G genomes that carry an insertion at the 2C-3A junction have been repeatedly detected in different countries [ 4 ]. This insertion is phylogenetically related to papain-like cysteine protease (PL-CP) sequences of swine toroviruses (family Tobaniviridae , genus Torovirus ) and was probably acquired through recombination.…”

“…In the past, two EV-Bs that infect humans, namely CVB4 and CVB5, were able to cross the species barrier to establish sustained transmission among swine [ 4 , 12 , 24 ]. To our knowledge, capability of EV-Cs to infect swine has never been demonstrated.…”

“…More than 300 virus types have been described and classified into 15 species: Enterovirus A to Enterovirus L and Rhinovirus A to Rhinovirus C [ 3 ]. Besides EVs that circulate among humans, tens of EV types were detected in other mammals, including non-human primates (NHPs), livestock, camels and rodents [ 4 ].…”