Virus isolate from carp: genetic characterization reveals a novel picornavirus with two aphthovirus 2A-like sequences

Abstract

Picornaviruses have been isolated from a variety of hosts, mainly mammals and birds. Here, we describe the sequence analysis of carp picornavirus 1 (CPV-1) F37/06 that was isolated from an organ pool (heart, brain, liver) of a common carp (Cyprinus carpio). This carp perished after an accidental discharge of liquid manure into a fish pond and presented without obvious clinical symptoms. Experimental intraperitoneal infection of young carp with CPV-1 revealed no clinical signs, but the virus was re-isolated from various organs. Sequence analysis of almost the complete genome (7632 nt excluding the poly-A tract) revealed a novel picornavirus clade. In phylogenetic trees, the polymerase sequence clusters with parechoviruses, duck hepatitis A virus, eel picornavirus and aquamavirus A. The ORF includes 6807 nt and encodes a polyprotein of 2269 amino acids. CPV-1 has a genome layout like that of picornaviruses except for the presence of two aphthovirus 2A- 3D pol shows the closest similarity to eel picornavirus, with an amino acid identity of 40.8 %,followed by human parechovirus (36.5 %), duck hepatitis A virus (32.7 %) and swine pasivirus (29.3 %). Both the unique genome organization and low sequence similarity support the assignment of CPV-1 to a novel picornavirus species within a novel genus.

Widespread distribution and structural diversity of Type IV IRESs in members of Picornaviridae

“…The structures of the IRESs of Bluegill picornavirus (BGPV-1) (Barbknecht et al, 2014), Carp picornavirus 1 (CPV-1)(Lange et al, 2014) and Fathead minnow picornavirus (FHMPV) (Phelps et al, 2014), three species in the proposed genus Limnipivirus , are not known. BLAST searches identified 47–102 nt-long elements with 64–74% identity to the FHMPV 5’UTR in the 5’UTRs of porcine sapelovirus 1, bat picornavirus 2 (BPV-2), Feline sakobuvirus A (SakV-A1) and Ia io picornavirus 1 (IiPV-1).…”

Structures and Corresponding Functions of Five Types of Picornaviral 2A Proteins

“…This phenomenon is unique to picornaviruses. The members of Limnipivirus contains two Aphthovirus -like 2A proteins (Barbknecht et al, 2014; Lange et al, 2014). The LV also contains two 2A proteins, but one is Aphthovirus -like 2A and the other is Parechovirus -like 2A (Johansson et al, 2002).…”

A multiplex RT-PCR assay for the detection of fish picornaviruses

“…However, CPV-1 does not cause any clinical illness in carp and the disease causing potential of FHMPV is currently unknown (Lange et al, 2014;Phelps et al, 2014). Phylogenetic analysis of the four picornavirus (BGPV-1, CPV-1, EPV-1 and FHMPV) genomes reveals that these viruses can potentially belong to four new species in the family Picornaviridae (Barbknecht et al, 2014;Fichtner et al, 2013;Lange et al, 2014;Phelps et al, 2014).…”

“…Little was known about picornaviruses in fish until recent reports of novel picornaviruses in common carp (Cyprinus carpio; Lange et al, 2014), European glass eel (Anguilla anguilla; Fichtner et al, 2013), bluegill (Lepomis macrochirus; Barbknecht et al, 2014), and fathead minnows (Pimephales promelas; Phelps et al, 2014). These viruses are herein referred to as carp picornavirus-1 (CPV-1), eel picornavirus-1 (EPV-1), bluegill picornavirus-1 (BGPV-1) and fathead minnow picornavirus (FHMPV).…”