Isolation and Full-Length Sequence Analysis of a Pestivirus from Aborted Lamb Fetuses in Italy.

Enrica Sozzi,Davide Lelli,Fabio Carlo Bencetti,Antonio Lavazza,Ana Moreno,Chiara Chiapponi,Alice Prosperi,Alessandra Gaffuri

doi:10.3390/v11080744

Abstract

Pestiviruses are distributed worldwide and are responsible for a variety of economically important diseases. They are not very host-specific, and thus sheep can be infected by well-known pestiviruses like bovine viral diarrhea virus (BVDV) and border disease virus (BDV), as well as by other recently discovered pestivirus species. The aim of this study is to describe the isolation and characterization of four pestivirus strains detected in aborted lamb fetuses from a single farm in the Brescia province (Northern Italy). A total of twelve aborted fetuses were collected and examined. After necropsy, organs were tested for the presence of infectious agents known as potential causes of abortion (Brucella spp., Listeria spp., Coxiella burnetii, Chlamydophila spp., Mycoplasma spp., Neospora caninum, and Toxoplasma gondii), and submitted to viral identification by isolation on Madin Darby bovine kidney (MDBK) cell culture and by PCR assay for Schmallenberg virus and pan-pestivirus RT-PCR real time assay. Three viral strains (Ovine/IT/1756/2017, Ovine/IT/338710-2/2017, and Ovine/IT/338710-3/2017) were isolated in the absence of cytopathic effects (CPEs) in cell cultures and identified with RT-PCR. Another pestivirus strain (Ovine/IT/16235-2/2018) was detected by PCR, but was not successfully isolated. Complete sequence genomic data of the three isolated viruses showed that they were highly similar, differed genetically from known pestivirus species, and were closely related to classical swine fever virus (CSFV). Beyond the identification of new ovine pestiviruses, this study indicates that a systematic diagnostic approach is important to identify the presence and map the distribution of both known and emerging pestiviruses.

Highlights

The genus Pestivirus within the family Flaviviridae has been recently classified, according to the International Committee on Taxonomy of Viruses (ICTV), into 11 viral species named from A to K, that include the four original species (bovine viral diarrhea virus (BVDV) type 1 (Pestivirus A), BVDV type 2 (Pestivirus B), classical swine fever virus (CSFV) (Pestivirus C), and border disease virus (BDV)(Pestivirus D)) as well as other pestiviruses recently classified as new pestivirus species [1].Pestiviruses have positive-stranded RNA genomes with lengths of approximately 12.3 kb, which contain one large open reading frame flanked by 50 and 30 untranslated regions (UTRs)
Madin Darby bovine kidney (MDBK) cell culture and by PCR assay for Schmallenberg virus and pan-pestivirus RT-PCR real time assay
This study describes the isolation and complete genome sequence of three pestiviruses detected in aborted lamb fetuses from a single farm located in the Brescia province of Northern Italy

Summary

Introduction

The genus Pestivirus within the family Flaviviridae has been recently classified, according to the International Committee on Taxonomy of Viruses (ICTV), into 11 viral species named from A to K, that include the four original species (bovine viral diarrhea virus (BVDV) type 1 (Pestivirus A), BVDV type 2 (Pestivirus B), classical swine fever virus (CSFV) (Pestivirus C), and border disease virus (BDV)(Pestivirus D)) as well as other pestiviruses recently classified as new pestivirus species [1].Pestiviruses have positive-stranded RNA genomes with lengths of approximately 12.3 kb, which contain one large open reading frame flanked by 50 and 30 untranslated regions (UTRs). The genus Pestivirus within the family Flaviviridae has been recently classified, according to the International Committee on Taxonomy of Viruses (ICTV), into 11 viral species named from A to K, that include the four original species (bovine viral diarrhea virus (BVDV) type 1 (Pestivirus A), BVDV type 2 (Pestivirus B), classical swine fever virus (CSFV) (Pestivirus C), and border disease virus (BDV). (Pestivirus D)) as well as other pestiviruses recently classified as new pestivirus species [1]. Pestiviruses have positive-stranded RNA genomes with lengths of approximately 12.3 kb, which contain one large open reading frame flanked by 50 and 30 untranslated regions (UTRs). The structural proteins are represented by the capsid protein C and three envelope proteins (Erns , E1, and E2). The remaining ones are non-structural (NS) proteins.

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