Detection and Molecular Characterization of Two Gammaherpesviruses from Pantesco Breed Donkeys during an Outbreak of Mild Respiratory Disease.

Francesco Mira,Santina Di Bella,Calogero Castronovo,Davide Lelli,Annalisa Guercio,Domenico Vicari,Antonio Lavazza,Roberto Puleio,Vincenza Cannella,Giorgia Schirò,Gabriele Chiaramonte,Giuseppa Purpari,Marta Canuti

doi:10.3390/v13081527

Abstract

Equid and asinine gammaherpesviruses (GHVs; genus Percavirus) are members of the Herpesviridae family. Though GHVs have been reported in horse populations, less studies are available on gammaherpesviral infections in donkeys. This study reports the co-infection with two GHVs in Pantesco breed donkeys, an endangered Italian donkey breed. Samples (n = 124) were collected on a breeding farm in Southern Italy from 40 donkeys, some of which were healthy or presented erosive tongue lesions and/or mild respiratory signs. Samples were analysed by using a set of nested PCRs targeting the DNA polymerase, glycoprotein B, and DNA-packaging protein genes, and sequence and phylogenetic analyses were performed. Twenty-nine donkeys (72.5%) tested positive, and the presence of Equid gammaherpesvirus 7 and asinine herpesvirus 5 was evidenced. In 11 animals, we found evidence for co-infection with viruses from the two species. Virions with herpesvirus-like morphology were observed by electron microscopic examination, and viruses were successfully isolated in RK-13-KY cell monolayers. The histological evaluation of tongue lesions revealed moderate lympho-granulocytic infiltrates and rare eosinophilic inclusions. The detection of GHVs in this endangered asinine breed suggests the need long-life monitoring within conservation programs and reinforces the need for further investigations of GHV’s pathogenetic role in asinine species.

Highlights

The Herpesviridae family includes viruses infecting a wide range of animals
From the analysis of all samples (n = 124) collected from the 40 donkeys, 65 samples from 29 donkeys (72.5%) tested positive to the pan-herpesvirus nested-PCR targeting the DNA polymerase (DPOL) gene (Supplementary Table S1)
We examined a total of 59 samples collected from 23 animals at three different time points (Figure 2), from which we obtained 94 high-quality sequences

Summary

Introduction

The Herpesviridae family (order Herpesvirales) includes viruses infecting a wide range of animals. Herpesviruses have been described in horses and, more rarely, other equids such as zebras, donkeys, and hybrids (mules and hinnies) [1,2,3]. As proposed by the International Committee on Taxonomy of Viruses (ICTV), the Herpesviridae family is divided into three subfamilies: Alphaherpesvirinae, Betaherpesvirinae, and Gammaherpesvirinae [4]. Herpesviruses (HVs) described in domestic equids are included in both Alphaherpesvirinae and Gammaherpesvirinae subfamilies. Other alphaherpesviruses of horses related to EqAHV-1 and EqAHV-3 (referred to as EqAHV-6 and 8) are less frequently described and affect other related domestic species such as donkeys, in which they are referred to as asinine herpesvirus 1 and 3, respectively [5,6,7]

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