First Detection of Recombinant Enterovirus G Carrying a Torovirus Papain-like cysteine protease Gene from India

Abstract

Enterovirus G (EV-G) comprising 20 genotypes (G1-G20) are associated with various disease conditions in pig populations. The recombination between homologous EV-G is a driving force behind evolution but the recombination with a virus from a heterologous family is a rare event. Presently, two types of recombinant EV-G strains containing torovirus papain-like cysteine protease (PLCP) at 2C-3A junction (Type I) and in place of structural proteins (Type II) are reported. The present study conducted to reveal RNA virome in diarrheic piglet's faeces retrieved genome coding for a complete polyprotein of EV-G1. The detected EV-G1 strain represents the first type I recombinant from India. The polyprotein of the strain exhibiting 97% amino acid identity was closely related to the Chinese strain. Furthermore, the EV-G1-PLCP strain was found to originate from South Korean, Chinese, and Japanese strains with breakpoints at nucleotide (nt) position 1323 and 4725. Genetic and phylogenetic analysis of VP1 and PLCP of the study strain demonstrated its closeness to EV-G1-PLCP strains from South Korea KOR/KNU-1811/2018/G1-PLCP. The present study advances the knowledge about the genetic evolution of EV-G from gaining virulence genes from different virus family. Keywords: Enterovirus G, torovirus, Cross-order Recombinant, papain-like cysteine protease sequence