Genomic characterization of a new bovine picornavirus (boosepivirus) in diarrheal cattle and detection in different states of the United States, 2019

Metagenomic insights into the complex viral composition of the enteric RNA virome in healthy and diarrheic calves from Ethiopia

BACKGROUND

Viruses and the virome have received increased attention in the context of calf diarrhea and with the advancement of high-throughput sequencing the detection and discovery of viruses has been improved. Calf diarrhea, being the main contributor to calf morbidity and mortality, is a major issue within the livestock sector in Ethiopia. However, studies on viruses and the virome in calves is lacking in the country. Therefore, we utilized viral metagenomics to investigate the diversity of RNA viruses in healthy and diarrheic calves from central Ethiopia.

METHODS

Fecal material from 47 calves were collected, pooled, and sequenced using Illumina. Following sequencing, the virome composition and individual viral sequences were investigated using bioinformatic analysis.

RESULTS

The metagenomic analysis revealed the presence of several RNA viruses, including rotavirus and bovine coronavirus, known causative agents in calf diarrhea. In addition, several enteric RNA viruses that have not been detected in cattle in Ethiopia previously, such as norovirus, nebovirus, astrovirus, torovirus, kobuvirus, enterovirus, boosepivirus and hunnivirus were identified. Furthermore, a highly divergent viral sequence, which we gave the working name suluvirus, was found. Suluvirus showed a similar genome structure to viruses within the Picornaviridae family and phylogenetic analysis showed that it clusters with crohiviruses. However, due to its very divergent amino acid sequence, we propose that suluvirus represent either a new genus within the Picornaviridae or a new species within crohiviruses.

CONCLUSIONS

To our knowledge, this is the first characterization of the RNA virome in Ethiopian cattle and the study revealed multiple RNA viruses circulating in both diarrheic and healthy calves, as well as a putative novel virus, suluvirus. Our study highlights that viral metagenomics is a powerful tool in understanding the divergence of viruses and their possible association to calf diarrhea, enabling characterization of known viruses as well as discovery of novel viruses.

Metagenomic analysis reveals high diversity of gut viromes in yaks (Bos grunniens) from the Qinghai-Tibet Plateau

The Qinghai-Tibet Plateau (QTP), renowned for its exceptional biological diversity, is home to numerous endemic species. However, research on the virology of vulnerable vertebrates like yaks remains limited. In this study, our objective was to use metagenomics to provide a comprehensive understanding of the diversity and evolution of the gut virome in yak populations across different regions of the QTP. Our findings revealed a remarkably diverse array of viruses in the gut of yaks, including those associated with vertebrates and bacteriophages. Notably, some vertebrate-associated viruses, such as astrovirus and picornavirus, showed significant sequence identity across diverse yak populations. Additionally, we observed differences in the functional profiles of genes carried by the yak gut virome across different regions. Moreover, the virus-bacterium symbiotic network that we discovered holds potential significance in maintaining the health of yaks. Overall, this research expands our understanding of the viral communities in the gut of yaks and highlights the importance of further investigating the interactions between viruses and their hosts. These data will be beneficial for revealing the crucial role that viruses play in the yak gut ecology in future studies.

Identification of a new bovine picornavirus (Boosepivirus) in the Republic of Korea

IMPORTANCE

Despite advancements in herd management, feeding, and pharmaceutical interventions, neonatal calf diarrhea (NCD) remains a major global health concern. Bacteria, viruses, and parasites are the major contributors to NCD. Although several pathogens have been identified in the Republic of Korea (ROK), the etiological agents of numerous NCD cases have not been identified.

OBJECTIVE

To identify, for the first time, the prevalence and impact of Boosepivirus (BooV) on calf diarrhea in the ROK.

METHODS

Here, the unknown cause of calf diarrhea was determined using metagenomics We then explored the prevalence of certain pathogens, including BooV, that cause NCD. Seventy diarrheal fecal samples from Hanwoo (Bos taurus coreanae) calves were analyzed using reverse transcriptase and quantitative real-time polymerase chain reaction for pathogen detection and BooV isolate sequencing.

RESULTS

The complete genome of BooV was detected from unknown causes of calf diarrhea. And also, BooV was the most frequently detected pathogen (35.7%) among 8 pathogens in 70 diarrheic feces from Hanwoo calves. Co-infection analyses indicated that most BooV-positive samples were solely infected with BooV, indicating its significance in NCD in the ROK. All isolates were classified as BooV B in phylogenetic analysis.

CONCLUSIONS AND RELEVANCE

This is the first study to determine the prevalence and molecular characteristics of BooV in calf diarrhea in the ROK, highlighting the potential importance of BooV as a causative agent of calf diarrhea and highlighting the need for further research on its epidemiology and pathogenicity.

Identification and Genomic Characterization of Bovine Boosepivirus A in the United States and Canada

Boosepivirus is a new genus in the Picornaviridae family. Boosepiviruses (BooVs) are genetically classified into three species: A, B, and C. Initially, Boosepivirus A and B were identified in cattle, whereas Boosepivirus C was detected in sheep. Recent evidence showed that Boosepivirus B was detected in sheep and Boosepivirus C was identified in goats, suggesting that Boosepvirus might cross the species barrier to infect different hosts. Different from BooV B, BooV A is less studied. In the present study, we reported identification of two North American BooV A strains from cattle. Genomic characterization revealed that US IL33712 (GenBank accession #PP035161) and Canada 1087562 (GenBank accession #PP035162) BooV A strains are distantly related to each other, and US IL33712 is more closely correlated to two Asian BooV A strains. US-strain-specific insertions, NorthAmerican-strain-specific insertions, and species A-specific insertions are observed and could contribute to viral pathogenicity and host adaptation. Our findings highlight the importance of continued surveillance of BooV A in animals.

Identification and Genomic Characterization of Bovine Boosepivirus A in the United States and Canada

Boosepivirus is a new genus in the Picornaviridae family. Boosepiviruses (BooVs) are genetically classified into three species: A, B, and C. Initially, Boosepivirus A and B were identified in cattle, whereas Boosepivirus C was detected in sheep. Recent evidence showed that Boosepivirus B was detected in sheep and Boosepivirus C was identified in goats, suggesting that Boosepvirus might cross the species barrier to infect different hosts. Different from BooV B, BooV A is less studied. In the present study, we reported identification of two North American BooV A strains from cattle. Genomic characterization revealed that US IL33712 (GenBank accession #PP035161) and Canada 1087562 (GenBank accession #PP035162) BooV A strains are distantly related to each other, and US IL33712 is more closely correlated to two Asian BooV A strains. US-strain-specific insertions, NorthAmerican-strain-specific insertions, and species A-specific insertions are observed and could contribute to viral pathogenicity and host adaptation. Our findings highlight the importance of continued surveillance of BooV A in animals.

Systematic Surveillance of an Emerging Picornavirus among Cattle and Sheep in China

Emerging viruses are a constant threat to human and animal health. Boosepivirus is a novel picornavirus considered a gastrointestinal pathogen and has broken out in recent years. In 2020, we identified a strain of boosepivirus NX20-1 from Chinese calf feces and performed genetic characterization and evolutionary analysis. NX20-1 was closely related to the Japanese strain Bo-12-38/2009/JPN and belonged to Boosepivirus B. We found that 64 of 603 samples (10.6%) from 20 different provinces across the country were positive for boosepivirus by reverse transcription (RT)-PCR. Further, coinfection with other diarrheal pathogens was also present in 35 of these positive samples. Importantly, we found the prevalence of boosepivirus in sheep as well, indicating that Boosepivirus can infect different domestic animals. Our data suggest that boosepivirus is a potential diarrheal pathogen, but the pathogenicity and the mechanism of pathogenesis need further study. IMPORTANCE We identified a novel picornavirus, boosepivirus, for the first time in China. Genetic evolutionary analysis revealed that NX20-1 strain was closely related to the Japanese strain Bo-12-38/2009/JPN and belonged to Boosepivirus B. In addition, we found that the virus was prevalent in China with an overall positivity rate of 10.6% (64 of 603 samples), and there was significant coinfection with other pathogens. Importantly, we found the prevalence of boosepivirus in sheep as well, suggesting that boosepivirus has a risk of spillover and can be transmitted across species.