Isolation and Molecular Characterization of a Novel Picornavirus from Baitfish in the USA

Abstract

During both regulatory and routine surveillance sampling of baitfish from the states of Illinois, Minnesota, Montana, and Wisconsin, USA, isolates (n = 20) of a previously unknown picornavirus were obtained from kidney/spleen or entire viscera of fathead minnows (Pimephales promelas) and brassy minnows (Hybognathus hankinsoni). Following the appearance of a diffuse cytopathic effect, examination of cell culture supernatant by negative contrast electron microscopy revealed the presence of small, round virus particles (∼30–32 nm), with picornavirus-like morphology. Amplification and sequence analysis of viral RNA identified the agent as a novel member of the Picornaviridae family, tentatively named fathead minnow picornavirus (FHMPV). The full FHMPV genome consisted of 7834 nucleotides. Phylogenetic analysis based on 491 amino acid residues of the 3D gene showed 98.6% to 100% identity among the 20 isolates of FHMPV compared in this study while only 49.5% identity with its nearest neighbor, the bluegill picornavirus (BGPV) isolated from bluegill (Lepomis macrochirus). Based on complete polyprotein analysis, the FHMPV shared 58% (P1), 33% (P2) and 43% (P3) amino acid identities with BGPV and shared less than 40% amino acid identity with all other picornaviruses. Hence, we propose the creation of a new genus (Piscevirus) within the Picornaviridae family. The impact of FHMPV on the health of fish populations is unknown at present.

Detection and molecular characterization of a novel piscine-myocarditis-like virus from baitfish in the USA

“…Virus isolation was performed according to the US Fish and Wildlife Service and American Fisheries Society -Fish Health Section Blue Book as described previously [9,11]. Briefly, a 10 % homogenate of the entire viscera was prepared in Hanks' balanced salt solution followed by centrifugation at 2500 9 g for 15 min at 4°C.…”

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

“…Also included in the study were eight strains of picornaviruses isolated recently at the MVDL from fathead minnows (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).…”

“…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).…”

A highly divergent picornavirus in an amphibian, the smooth newt (Lissotriton vulgaris)

“…Picornaviruses include a wide range of pathogens (Knowles et al, 2012; http://www.picornaviridae.com) and have been found in various vertebrate host species including humans and other mammals (Kapoor et al, 2008b), birds (Boros et al, 2014) and recently in fish (Fichtner et al, 2013;Barbknecht et al, 2014;Lange et al;2014;Phelps et al, 2014) and reptiles (Heuser et al, 2010;Ng et al, 2015). All known picornaviruses in lower vertebrates (in fish and reptiles) represent a potentially novel but presently unassigned species or genus (http://www.picornaviridae.…”