Presence of bovine hepacivirus in Turkish cattle

Two bovine hepacivirus genome sequences from U.S. cattle

Bovine hepacivirus (BoHV) is closely related to the hepatitis C virus (HCV) in humans and can cause both acute and chronic liver infections in cattle. BoHV was first identified in Ghana and Germany in 2015 and since then it has been detected and characterized in other countries around the world, but no strains have been sequenced from U.S. cattle. To date, BoHV has been classified into 2 genotypes (1 and 2), with genotype 1 being further divided into 11 subtypes (A-K). However, the true genetic diversity of BoHV is likely underestimated given limited surveillance and a lack of published genome sequences. Here, we sequenced 2 nearly complete BoHV genomes from serum samples collected in 2019 from beef cattle in Missouri. Sequence comparisons and phylogenetic analysis showed that isolate MARC/2019/60 had high sequence homology with genotype 1, subtype E isolates from China. In contrast, isolate MARC/2019/50 represented a novel BoHV subtype within genotype 2. Thus, we report the first genomic characterization of BoHV isolates from U.S. cattle, and the second complete BoHV2 genome worldwide. This work increases our knowledge of the global genetic diversity of BoHV and demonstrates the co-circulation of divergent BoHV strains in U.S. cattle.

Molecular detection and genetic characterization of bovine hepacivirus identified in ticks collected from cattle in Harbin, northeastern China

Bovine hepacivirus (BovHepV) is a member of the genus Hepacivirus of the family Flaviviridae, which can cause acute or persistent infections in cattle. Currently, BovHepV strains identified in cattle populations worldwide can be classified into two genotypes with eight subtypes in genotype 1. BovHepV has been identified in a wide geographic area in China. Interestingly, the viral RNA of BovHepV has also been detected in ticks in Guangdong province, China. In this study, Rhipicephalus microplus tick samples were collected in Heilongjiang province, northeastern China, and BovHepV was screened with an overall positive rate of 10.9%. Sequence comparison and phylogenetic analysis showed that the BovHepV strains detected in this study belong to the subtype G. This is the first report about the detection of BovHepV in ticks in Heilongjiang province, China, which expands our knowledge that ticks may be a transmission vector of BovHepV.

First identification of bovine hepacivirus in wild boars

Hepatitis C virus (HCV) is a major cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma in humans. Humans were long considered the only hosts of Hepacivirus. Recently HCV-like sequences have been found in several animal species. Hepaciviruses are considered species-specific but a wider host range and a zoonotic role has been hypothesized. We report the first detection of bovine hepacivirus (BovHepV) sequences in wild boars. A total of 310 wild boars hunted in Campania region were investigated with a pan-hepacivirus nested-PCR protocol for the NS3 gene. Hepacivirus RNA was detected in 5.8% of the animals. Sequence and phylogenetic analysis showed high homology with BovHepV subtype F, with nucleotide identity of 99%. The positive wild boars were georeferenced, revealing high density of livestock farms, with no clear distinction between animal husbandry and hunting areas. These findings might suggest the ability of BovHepV to cross the host-species barrier and infect wild boars.

Expanded Diversity and Host Range of Bovine Hepacivirus—Genomic and Serological Evidence in Domestic and Wild Ruminant Species

The hepatitis C virus (HCV)-related bovine hepacivirus (BovHepV) can cause acute as well as persistent infections in cattle. The true clinical relevance of the virus is not yet known. As reliable antibody detection methods are lacking and prevalence studies have only been conducted in cattle and few countries to date, the true distribution, genetic diversity, and host range is probably greatly underestimated. In this study, we applied several RT-PCR methods and a nano-luciferase-based immunoprecipitation system (LIPS) assay to analyze bovine serum samples from Bulgaria as well as wild ruminant sera from Germany and the Czech Republic. Using these methods, BovHepV infections were confirmed in Bulgarian cattle, with viral genomes detected in 6.9% and serological reactions against the BovHepV NS3 helicase domain in 10% of bovine serum samples. Genetic analysis demonstrated co-circulation of highly diverse BovHepV strains in Bulgarian cattle, and three novel BovHepV subtypes within the genotype 1 could be defined. Furthermore, application of a nested RT-PCR led to the first description of a BovHepV variant (genotype 2) in a wild ruminant species. The results of this study significantly enhance our knowledge of BovHepV distribution, genetic diversity, and host range.

Identification and Genetic Characterization of Bovine Hepacivirus in China: A Large Scale Epidemiological Study

Bovine hepacivirus (BovHepV) is a novel virus that was recently discovered in Ghana and Germany in 2015. Until now, this virus has been identified in cattle population worldwide and is classified into subtypes A–G. To fully understand the epidemic situation and genetic characteristic of BovHepV in China, a total of 612 cattle serum samples were collected from 20 farms in seven provinces and municipality in China between 2018 and 2020 and were tested for the presence of BovHepV RNA via semi-nested PCR. The results demonstrated that 49 (8.0%) samples were BovHepV RNA-positive. It is noted that BovHepV infection in yak was confirmed for the first time. BovHepV was detected in all the seven provinces, with the positive rate ranging from 3.1% to 13.3%, which indicates a wide geographical distribution pattern of BovHepV in China. Sequencing results revealed that 5′ UTR of the 49 field BovHepV strains have a nucleotide similarity of 96.3%–100% between each other and 93.9%–100% with previously reported BovHepV strains. In addition, genetic analysis identified five critical nucleotide sites in 5′ UTR to distinguish different subtypes, which was further verified by genomic sequencing and nucleotide similarity analysis. All the 49 Chinese field BovHepV strains were classified into subtype G and this subtype is only determined in cattle in China currently. This study will provide insights for us to better understand the epidemiology and genetic diversity of BovHepV.

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BovHepV was detected in seven provinces in China between 2018 and 2020.

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BovHepV was prevalent in cattle with the positive rate ranging from 3.1% to 13.3%.

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Five critical nucleotide sites in 5′ UTR could distinguish BovHepV subtypes.

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The Chinese field BovHepV strains were classified into subtype G.

A Novel Subtype of Bovine Hepacivirus Identified in Ticks Reveals the Genetic Diversity and Evolution of Bovine Hepacivirus

Hepaciviruses represent a group of viruses that pose a significant threat to the health of humans and animals. New members of the genus Hepacivirus in the family Flaviviridae have recently been identified in a wide variety of host species worldwide. Similar to the Hepatitis C virus (HCV), bovine hepacivirus (BovHepV) is hepatotropic and causes acute or persistent infections in cattle. BovHepVs are distributed worldwide and classified into two genotypes with seven subtypes in genotype 1. In this study, three BovHepV strains were identified in the samples of ticks sucking blood on cattle in the Guangdong province of China, through unbiased high-throughput sequencing. Genetic analysis revealed the polyprotein-coding gene of these viral sequences herein shared 67.7–84.8% nt identity and 76.1–95.6% aa identity with other BovHepVs identified worldwide. As per the demarcation criteria adopted for the genotyping and subtyping of HCV, these three BovHepV strains belonged to a novel subtype within the genotype 1. Additionally, purifying selection was the dominant evolutionary pressure acting on the genomes of BovHepV, and genetic recombination was not common among BovHepVs. These results expand the knowledge about the genetic diversity and evolution of BovHepV distributed globally, and also indicate genetically divergent BovHepV strains were co-circulating in cattle populations in China.

Molecular characterization and comparison of diagnostic methods for bovine respiratory viruses (BPIV-3, BRSV, BVDV, and BoHV-1) in field samples in northwestern Turkey

The aim of this study was to evaluate the compatibility among virus isolation (VI), ELISA, and PCR for diagnosis of the major viral agents (BPIV-3, BRSV, BVDV, and BoHV-1) responsible for BRD in the field samples. For that purpose, a total of 193 samples (133 nasal swabs and 60 lung tissue samples) from cattle with respiratory signs in northwestern Turkey were examined. For VI, all the samples were inoculated at least 3 blind passages onto MDBK cell culture. In addition, the samples were tested by hemadsorption assay and RT-PCR for BPIV-3; nested RT-PCR for BRSV; immunoperoxidase monolayer assay, antigen-ELISA, and RT-PCR for BVDV; and antigen-ELISA and PCR for BoHV-1. The detected 1 (0.52%) BPIV-3 isolate was found to be in the genotype BPIV-3c. No BRSV isolate could be obtained, while 5 (2.59%) samples were evaluated positive in nested-RT PCR. The presence of BVDV antigen in 10 (5.18%) samples and the BVDV genome in 5 (2.59%) samples were detected, while non-cytopathogenic BVDV isolates were obtained only in 2 (1.04%) samples. The detected BVDV strains fell into the genetic clusters of BVDV-1a, -1f, and -1l. For detection of BoHV-1, although viral isolation and Ag-ELISA results were negative, presence of BoHV-1.1 genome was detected in 2 (1.04%) samples. By the results of VI, ELISA, and PCRs, 10.88% (21/193) of samples were found positive for the evaluated viruses. Depending on the obtained data, combined uses of the diagnostic methods were evaluated to be more reliable for routine diagnosis of bovine respiratory viruses.

Genetic heterogeneity of bovine hepacivirus in Italy

Viruses similar to human hepatitis C virus (HCV) in the Hepacivirus genus have been identified in several animal hosts, including cattle. Since its first discovery in Germany, bovine hepacivirus (BovHepV) has been described in several countries globally. However, limited data are available on BovHepV epidemiology and genetic variability. The aim of this study was to investigate the prevalence and genetic diversity of BovHepV in Italy. Viral RNA was identified in 37 (0.15%) of 24,820 bovine sera, with titres ranging from 1.09 × 10³ to 8.27 × 10⁶ RNA copies/ml. Upon sequencing and phylogenetic analysis of the 5'UTR and NS3 genomic portions, the Italian BovHepV strains segregated into at least four distinct subtypes (A, B, C and F) that are also co-circulating globally.

Complete genome sequence of a novel bovine hepacivirus from Yunnan, China

We detected a novel bovine hepacivirus N (HNV) subtype, IME_BovHep_01, in the serum of cattle in Tengchong, Yunnan, China, by high-throughput sequencing. The complete genome of IME_BovHep_01, was sequenced using an Illumina MiSeq sequencer and found to be 8850 nt in length, encoding one hypothetical protein. BLASTn analysis showed that the genome sequence shared similarity with the bovine hepacivirus isolate BovHepV_209/Ger/2014, with 88% query coverage and 70.8% identity. However, the highest similarity was to bovine hepacivirus N strain BRBovHep_RS963, for which only a partial genome sequence is available, with 68% query coverage and 81.5% identity. Sequence comparisons and phylogenetic analysis suggested that IME_BovHep_01 is a novel HNV subtype. Importantly, IME_BovHep_01 is the first member of this new genotype for which the complete genome sequence was determined.

Presence of a Novel Subtype of Bovine Hepacivirus in China and Expanded Classification of Bovine Hepacivirus Strains Worldwide into 7 Subtypes

The newest member of the Hepacivirus genus, bovine hepacivirus (BovHepV), was first identified in cattle in 2015 and is a novel hepacivirus C virus (HCV)-like virus. This virus has been detected in five countries so far and is classified into four subtypes. Bovine serum is commonly used for cell cultures and is considered the major source of viral contamination of pharmaceutical products. In this study, bovine serum samples were collected from seven countries located in Asia, America, Oceania, and Europe and were tested for BovHepV RNA using nested PCR, in order to: (i) obtain more knowledge on the geographical distribution and subtypes of BovHepV; and (ii) detect the potential contamination of BovHepV in commercial bovine serum samples used for cell culture propagation. The results demonstrated that bovine serum samples from individual donor cattle in China contained BovHepV RNA. After PCR, sequencing, and assembly, the genomes of the Chinese BovHepV strains were obtained. Genetic analysis of the polyprotein gene revealed a protein identity of <77% and a nucleotide identity of <85% between the Chinese BovHepV strains and all other previously reported BovHepV strains. Using cut-off values for determination of HCV genotypes and subtypes, BovHepV strains worldwide were classified into one unique genotype and seven subtypes. The BovHepV strains identified in the present study were classified into a novel subtype, which was provisionally designated subtype G. The genetic relationships among the different BovHepV subtypes were further confirmed through phylogenetic analysis. The present study provides critical insights into BovHepV’s geographical distribution and genetic variability.