Novel Picornavirus Detected in Wild Deer: Identification, Genomic Characterisation, and Prevalence in Australia

The genomic and epidemiological investigations of enteric viruses of domestic caprine (Capra hircus) revealed the presence of multiple novel viruses related to known strains of humans and ruminant livestock species

IMPORTANCE

Compared with other domestic animals, the virome and viral diversity of small ruminants especially in caprine are less studied even of its zoonotic potential. In this study, the enteric virome of caprine was investigated in detail using next-generation sequencing and reverse transcription PCR techniques. The complete or nearly complete genomes of seven novel viruses were determined which show a close phylogenetic relationship to known human and ruminant viruses. The high similarity between the identified caprine tusavirus (family Parvoviridae) and an unassigned CRESS DNA virus with closely related human strains could indicate the (reverse) zoonotic potential of these viruses. Others, like astroviruses (family Astroviridae), enteroviruses, or novel caripiviruses (named after the term caprine picornavirus) of family Picornaviridae found mostly in multiple co-infections in caprine and ovine, could indicate the cross-species transmission capabilities of these viruses between small ruminants.

Identification of Multiple Novel Viruses in Fecal Samples of Black-Necked Cranes Using Viral Metagenomic Methods

The black-necked crane is the only species of crane that lives in the high-altitude region of the Tibet Plateau. At present, there is little research on viral diseases of the black-necked crane (Grus nigricollis). In this study, a viral metagenomic approach was employed to investigate the fecal virome of black-necked cranes in Saga County, Shigatse City, Tibet, China. The identified virus families carried by black-necked cranes mainly include Genomoviridae, Parvoviridae, and Picornaviridae. The percentages of sequence reads belonging to these three virus families were 1.6%, 3.1%, and 93.7%, respectively. Among them, one genome was characterized as a novel species in the genus Grusopivirus of the family Picornaviridae, four new parvovirus genomes were obtained and classified into four different novel species within the genus Chaphamaparvovirus of the subfamily Hamaparvovirinae, and four novel genomovirus genomes were also acquired and identified as members of three different species, including Gemykroznavirus haeme1, Gemycircularvirus ptero6, and Gemycircularvirus ptero10. All of these viruses were firstly detected in fecal samples of black-necked cranes. This study provides valuable information for understanding the viral community composition in the digestive tract of black-necked cranes in Tibet, which can be used for monitoring, preventing, and treating potential viral diseases in black-necked cranes.

Evidence of Australian wild deer exposure to N. caninum infection and potential implications for the maintenance of N. caninum sylvatic cycle

Infections with the coccidian parasite Neospora caninum affect domestic and wild animals worldwide. In Australia, N. caninum infections cause considerable losses to the cattle industry with seroprevalence of 8.7% in beef and 10.9% in dairy cattle. Conversely, the role of wild animals, in maintaining the parasite cycle is also unclear. It is possible that native or introduced herbivorous species could be reservoir hosts of N. caninum in Australia, but to date, this has not been investigated. We report here the first large-scale screening of N. caninum antibodies in Australian wild deer, spanning three species (fallow, red and sambar deer). Consequently, we also assessed two commercial cELISA tests validated for detecting N. caninum in cattle for their ability to detect N. caninum antibodies in serum samples of wild deer. N. caninum antibodies were detected in 3.7% (7/189, 95% CI 1.8 - 7.45) of the wild deer serum samples collected in south-eastern Australia (n = 189), including 97 fallow deer (Dama dama), 14 red deer (Cervus elaphus), and 78 sambar deer (Rusa unicolor). Overall, our study provides the first detection of N. caninum antibodies in wild deer and quantifies deer's potential role in the sylvatic cycle of N. caninum.

A One-Year Retrospective Analysis of Viral and Parasitological Agents in Wildlife Animals Admitted to a First Aid Hospital

This study aimed to provide information on the presence and frequency of viral and parasitic agents in wildlife presented to a Veterinary Teaching Hospital in 2020-2021. Serum and faecal samples were collected from 50 rescued animals (roe deer, fallow deer, foxes, badgers, pine martens, and porcupines) and examined by serological, molecular, and parasitological techniques. Transtracheal wash (TTW) was also collected post-mortem from roe deer. Overall, the results of the different techniques showed infections with the following viral and parasitic agents: Bovine Viral Diarrhea Virus, Small Ruminant Lentiviruses, Kobuvirus, Astrovirus, Canine Adenovirus 1, Bopivirus, gastrointestinal strongyles, Capillaria, Ancylostomatidae, Toxocara canis, Trichuris vulpis, Hymenolepis, Strongyloides, Eimeria, Isospora, Dictyocaulus, Angiostrongylus vasorum, Crenosoma, Dirofilaria immitis, Neospora caninum, Giardia duodenalis, and Cryptosporidium. Sequencing (Tpi locus) identified G. duodenalis sub-assemblages AI and BIV in one roe deer and one porcupine, respectively. Adult lungworms collected from the TTW were identified as Dictyocaulus capreolus (COX1 gene). This is the first molecular identification of G. duodenalis sub-assemblage AI and D. capreolus in roe deer in Italy. These results show a wide presence of pathogens in wild populations and provide an overview of environmental health surveillance.

First detection and molecular characteristics of bopivirus from goats in China

A metavirome analysis was performed and detected bopivirus in the diarrhoeal fecal samples of goats in China. A total of 136 fecal samples were collected from yeanlings between the dates of June 2021 and January 2022 in Sichuan province, China. Moreover, "Bopivirus B" strains were detected by a specific RT-PCR targeting the 3D gene of the virus. The results showed that the overall detection rate of "Bopivirus B" was 19.12% (26/136). Additionally, there was a higher detection rate (24.05%, 19/79) in the fecal samples collected from yeanlings with diarrhea compared to those from asymptomatic animals (12.28%, 7/57). In these samples, no other common diarrhea-causing pathogens were detected except for three enteric viruses, namely caprine enterovirus, caprine kobuvirus and caprine hunnivirus (with detection rates of 13.97, 13.97, and 8.82%, respectively). Subsequently, full-length VP4, VP2, VP3, and VP1 genes from "Bopivirus B"-positive samples were amplified, cloned, sequenced, and analyzed. The phylogenetic analysis performed on the VP1 genes revealed that the identified bopivirus belonged to genotype B1 (seven strains) and B2 (three strains) and presented a high genetic diversity. Furthermore, a complete genome sequence of a "Bopivirus B" strain (SWUN/B1/2022) was obtained using PCR from fecal sample of a diarrhoeal yeanling. The complete genome was 7,309 nucleotides in length with a standard picornavirus genome organization, and shares 93.10% and 91.10% nucleotide similarity with bopivirus B1 genotype strain ovine/TB14/2010-HUN and bopivirus B2 genotype strain goat/AGK16/2020-HUN, respectively. According to the species classification criteria put forward by the International Committee on Taxonomy of Viruses and VP1 genotype, the strain SWUN/B1/2022 belongs to the bopivirus B1. This strain has unique amino acid substitutions in the VP4, VP2, VP3, and VP1 genes. Moreover, genomic recombination analysis revealed that this strain may be a minor parental strain of bopivirus B1 ovine/TB14/2010-HUN. Evolutionary analysis based on the 2C and 3CD genes revealed that the new bopivirus B1 strain SWUN/B1/2022 presents a unique evolutionary pattern. This study provided evidence to suggest that "Bopivirus B" is circulating with substantial genetic diversity in goats in China at present, and the mixed infection of "Bopivirus B" with other enteric viruses should be considered to be a composite factor in the occurrence of viral diarrhea in goats.

Detection and characterization of bopiviruses in domestic and wild ruminants

Highly divergent picornaviruses (PVs) classified in the genus Bopivirus have been recently discovered on faecal samples from sheep and goats in Hungary and from fallow and red deer in Australia. In this study, we investigated the epidemiology of these novel viruses in domestic and wild ruminants from Northwestern Italian Alps by testing archival faecal samples collected from 128 sheep, 167 goats, 61 red deer (Cervus elaphus), 77 roe deer (Capreolus capreolus), 43 chamois (Rupicapra rupicapra) and 32 Alpine ibex (Capra ibex). Bopivirus RNA was detected in a total of 19 animals, including 14 sheep (10.9%), 2 red deer (3.3%), 1 roe deer (1.3%), 1 chamois (2.3 %) and 1 Alpine ibex (3.3 %), but not in goats. Upon sequence analysis of the 3D^RdRp region, the sequences generated from chamois, roe deer, Alpine ibex and ovine faecal samples showed the highest nucleotide identity (96.8-100%) to bopiviruses detected in goats and sheep from Hungarian farms, whereas strains found in red deer displayed the closest relatedness (90.8%-91.2%) to bopiviruses identified in fallow and red deer in Australia. The nearly complete genome sequence of strains 12/2020/ITA (ON497046) and 14-73/2020/ITA (ON497047) detected in an Alpine ibex and in a sheep, respectively, was determined by combining a modified 3'-RACE protocol with Oxford Nanopore Technologies sequencing platform. On phylogenetic analysis based on the complete polyprotein, both strains segregated into the candidate species Bopivirus B along with ovine and caprine strains detected in Hungary (90.0-94.6% nucleotide and 94.6-98.0% amino acid identities). The findings of this study expand the host range of these novel viruses and hint to a possible virus circulation between domestic ruminants and wild animals.

First Evidence of Entamoeba Parasites in Australian Wild Deer and Assessment of Transmission to Cattle

Australian wild deer populations have significantly expanded in size and distribution in recent decades. Due to their role in pathogen transmission, these deer populations pose a biosecurity risk to the livestock industry. However, little is known about the infection status of wild deer in Australia. The intestinal parasite Entamoeba bovis has been previously detected in farm and wild ruminants worldwide, but its epidemiology and distribution in wild ruminants remain largely unexplored. To investigate this knowledge gap, faecal samples of wild deer and domestic cattle from south-eastern Australia were collected and analysed for the presence of Entamoeba spp. using PCR and phylogenetic analysis of the conserved 18S rRNA gene. E. bovis parasites were detected at high prevalence in cattle and wild deer hosts, and two distinct Entamoeba ribosomal lineages (RLs), RL1 and RL8, were identified in wild deer. Phylogenetic analysis further revealed the existance of a novel Entamoeba species in sambar deer and a novel Entamoeba RL in fallow deer. While we anticipated cross-species transmission of E. bovis between wild deer and cattle, the data generated in this study demonstrated transmission is yet to occur in Australia. Overall, this study has identified novel variants of Entamoeba and constitutes the first report of Entamoeba in fallow deer and sambar deer, expanding the host range of this parasite. Epidemiological investigations and continued surveillance of Entamoeba parasites in farm ruminants and wild animals will be required to evaluate pathogen emergence and transmission to livestock.