Bovine papillomavirus 24: a novel member of the genus Xipapillomavirus detected in the Amazon region

Phylogenetic analysis and searching bovine papillomaviruses in teat papillomatosis cases in cattle by performing histopathology, immunohistochemistry, and transmission electron microscopy

Papillomaviruses are epitheliotropic in nature and cause proliferation in the skin, mucosa, and various internal organs of various animal species. The lesions they cause, specifically in cattle teats, lead to significant economic losses in the milk industry. In this study, we identified the bovine papillomaviruses (BPVs) responsible for teat papillomas in cattle. The tissue damage caused by the virus was examined histopathologically using immunohistochemical, transmission electron microscopy (TEM), and molecular methods. Additionally, sequence analyses were performed on the isolated field strains to better understand their genetic and phylogenetic relationships with previously reported isolates. Teat papillomatosis was confirmed in the collected samples by histopathological and immunohistochemical methods, which were followed by other diagnostic methods. Intranuclear virus particles were found in the epithelial cells during a TEM examination of teat lesions. BPV was detected in seven samples by performing PCR using degenerate primers and specific primers. The positive samples were used for typing through sequence analysis/PCR with type-specific primers. Three isolates from teat tissues with BPV infection were identified as BPV-6, two as BPV-10, one as BPV-2, and one as BPV-8. The five isolates identified through sequence analysis of positive samples belonged to the Xipapillomavirus 1 genus (one), the Epsilonpapillomavirus 1 genus (one), and the Deltapapillomavirus genus (one) (three). Furthermore, type-specific primers were found to be useful for molecular diagnosis of BPV, which occurs in the etiology of teat papillomas, followed by genotyping and primer generation during characterization. The detection of BPV types and their prevalence, biosafety measures in animal breeding, and the importance of vaccine research are all important.

Pteridium spp. and Bovine Papillomavirus: Partners in Cancer

Bovine papillomavirus (BPV) are a cause for global concern due to their wide distribution and the wide range of benign and malignant diseases they are able to induce. Those lesions include cutaneous and upper digestive papillomas, multiple histological types of urinary bladder cancers—most often associated with BPV1 and BPV2—and squamous cell carcinomas of the upper digestive system, associated with BPV4. Clinical, epidemiological and experimental evidence shows that exposure to bracken fern (Pteridium spp.) and other related ferns plays an important role in allowing viral persistence and promoting the malignant transformation of early viral lesions. This carcinogenic potential has been attributed to bracken illudane glycoside compounds with immune suppressive and mutagenic properties, such as ptaquiloside. This review addresses the role of BPV in tumorigenesis and its interactions with bracken illudane glycosides. Current data indicates that inactivation of cytotoxic T lymphocytes and natural killer cells by bracken fern illudanes plays a significant role in allowing viral persistence and lesion progression, while BPV drives unchecked cell proliferation and allows the accumulation of genetic damage caused by chemical mutagens. Despite limited progress in controlling bracken infestation in pasturelands, bracken toxins remain a threat to animal health. The number of recognized BPV types has steadily increased over the years and now reaches 24 genotypes with different pathogenic properties. It remains essential to widen the available knowledge concerning BPV and its synergistic interactions with bracken chemical carcinogens, in order to achieve satisfactory control of the livestock losses they induce worldwide.

The genetic diversity of "papillomavirome" in bovine teat papilloma lesions

Background

Papillomaviruses are small nonenveloped, circular double-stranded DNA viruses that belong to the Papillomaviridae family. To date, 29 Bos taurus papillomavirus (BPV) types have been described. Studies involving mixed BPV infections have rarely been reported in contrast to human papillomavirus (HPV), which is commonly described in numerous studies showing coinfections. Moreover, previous studies had shown that HPV coinfections increase the risk of carcinogenesis. In the present study, we used rolling-circle amplification followed by a high-throughput sequencing (RCA-HTS) approach in 23 teat papillomas from southern Brazil.

Results

Eleven well-characterized BPV types and 14 putative new BPV types were genetically characterized into the Xi, Epsilon and Dyoxipapillomavirus genera according to phylogenetic analysis of the L1 gene, which expands the previous 29 BPV types to 43. Moreover, BPV coinfections were detected in the majority (56.3%) of the papilloma lesions analyzed, suggesting a genetic diverse “papillomavirome” in bovine teat warts.

Conclusions

The data generated in this study support the possibility that a wide range of BPV is probably underdetected by conventional molecular detection tools, and that BPV coinfections are underestimated and probably genetic diverse. Additionally, 14 new BPV types were characterized, increasing the knowledge regarding BPV genetic diversity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42523-021-00114-3.

Complete genome and phylogenetic analysis of bovine papillomavirus type 15 in Southern Xinjiang dairy cow

Background

Bovine papilloma is a neoplastic disease caused by bovine papillomaviruses (BPVs), which were recently divided into 5 genera and at least 24 genotypes.

Objectives

The complete genome sequence of BPV type 15 (BPV Aks-02), a novel putative BPV type from skin samples from infected cows in Southern Xinjiang China, was determined by collecting warty lesions, followed by DNA extraction and amplicon sequencing.

Methods

DNA was analyzed initially by polymerase chain reaction (PCR) using the degenerate primers FAP59 and FAP64. The complete genome sequences of the BPV Aks-02 were amplified by PCR using the amplification primers and sequencing primers. Sequence analysis and phylogenetic analysis were performed using bio-informatic software.

Results

The nucleotide sequence of the L1 open reading frame (ORF) of BPV Aks-02 was 75% identity to the L1 ORF of BPV-9 reference strain from GenBank. The complete genome consisted of 7,189 base pairs (G + C content of 42.50%) that encoded 5 early (E8, E7, E1, E2, and E4) and 2 late (L1 and L2) genes. The E7 protein contained a consensus CX₂CX₂₉CX₂C zinc-binding domain and a LxCxE motif. Among the different members of this group, the percentages of the complete genome and ORFs (including 5 early and 2 late ORFs) sequence identity of BPV Aks-02 were closer to the genus Xipapillomavirus 1 of the Xipapillomavirus genus. Phylogenetic analysis and sequence similarities based on the L1 ORF of BPV Aks-02 revealed the same cluster.

Conclusions

The results suggest that BPV type (BPV Aks-02) clustered with members of the Xipapillomavirus genus as BPV 15 and were closely related to Xipapillomavirus 1.

Molecular detection and genetic diversity of bovine papillomavirus in dairy cows in Xinjiang, China

Background

Bovine papillomatosis is a type of proliferative tumor disease of skin and mucosae caused by bovine papillomavirus (BPV). As a transboundary and emerging disease in cattle, it poses a potential threat to the dairy industry.

Objectives

The aim of this study is to detect and clarify the genetic diversity of BPV circulating in dairy cows in Xinjiang, China.

Methods

122 papilloma skin lesions from 8 intensive dairy farms located in different regions of Xinjiang, China were detected by polymerase chain reaction. The genetic evolution relationships of various types of BPVs were analyzed by examining this phylogenetic tree.

Results

Ten genotypes of BPV (BPV1, BPV2, BPV3, BPV6, BPV7, BPV8, BPV10, BPV11, BPV13, and BPV14) were detected and identified in dairy cows. These were the first reported detections of BPV13 and BPV14 in Xinjiang, Mixed infections were detected, and there were geographical differences in the distribution of the BPV genotypes. Notably, the BPV infection rate among young cattle (< 1-year-old) developed from the same supply of frozen sperm was higher than that of the other young cows naturally raised under the same environmental conditions.

Conclusions

Genotyping based on the L1 gene of BPV showed that BPVs circulating in Xinjiang China displayed substantial genetic diversity. This study provided valuable data at the molecular epidemiology level, which is conducive to developing deep insights into the genetic diversity and pathogenic characteristics of BPVs in dairy cows.

Genomic and phylogenetic characterization of ChPV2, a novel goat PV closely related to the Xi-PV1 species infecting bovines

BACKGROUND

Papillomaviruses (PVs) infecting artiodactyls are very diverse, and only second in number to PVs infecting primates. PVs associated to lesions in economically important ruminant species have been isolated from cattle and sheep.

METHODS

Potential PV DNA from teat lesions of a Damascus goat was isolated, cloned and sequenced. The PV genome was analyzed using bioinformatics approaches to detect open reading frames and to predict potential features of encoded proteins as well as putative regulatory elements. Sequence comparison and phylogenetic analyses using the concatenated E1E2L2L1 nucleotide and amino acid alignments was used to reveal the relationship of the new PV to the known PV diversity and its closest relevants.

RESULTS

We isolated and characterized the full-genome of novel Capra hircus papillomavirus. We identified the E6, E7, E1, E2, L2, L1 open reading frames with protein coding potential and putative active elements in the ChPV2 proteins and putative regulatory genome elements. Sequence similarities of L1 and phylogenetic analyses using concatenated E1E2L2L1 nucleotide and amino acid alignments suggest the classification as a new PV type designated ChPV2 with a phylogenetic position within the XiPV genus, basal to the XiPV1 species. ChPV2 is not closely related to ChPV1, the other known goat PV isolated from healthy skin, although both of them belong confidently into a clade composed of PVs infecting cervids and bovids. Interestingly, ChPV2 contains an E6 open reading frame whereas all closely related PVs do not CONCLUSION: ChPV2 is a novel goat PV closely related to the Xi-PV1 species infecting bovines. Phylogenetic relationships and genome architecture of ChPV2 and closely related PV types suggest at least two independent E6 losses within the XiPV clade.

Detection and genomic characterization of Bovine papillomavirus isolated from Chinese native cattle

Bovine papillomaviruses (BPV) are small circular DNA viruses which can be widely spread in herd, inducing cattle tumours, therefore, leading economic losses in dairy and beef production industries. BPV-leads symptoms include cutaneous papillomas, fibropapillomas, urinary bladder and oesophageal carcinoma. As one of the most important producers of beef in the world, China has not provided systematic research to prevent the harm of BPV, particularly in papillomavirus molecular characterization which presents among Chinese native cattle which was known to have higher disease resistance. In this study, skin papilloma was observed and samples were collected following by histopathological analysis. We analysed all neoplasms samples and reviewed their degrees in acanthosis and/or hyperkeratosis. Full-length genomic sequencing was applied for all four isolated strains (JX180408, LA150909, HX160815, and BS160810) to exploring the molecular reason why BPV currently prevalent in Chinese native cattle. As a result, we identified that these four isolates were classified as BPV-1 and clustered into the Deltapapillomavirus genera. Our study also identified that BPV 1 isolates from Chinese indigenous cattle breeds belong to subtypes A which has a closer genetic background compare with their common ancestor and suggest it can be a more ancestral species. European isolates more recently diverged group (group B) contained almost exclusively European samples. In this study, we analysed the similarity of ORF between Chinese isolated BPV 1 and BPV 1 reference strains and listed results. This study provides the complete genomic characterization of BPVs circulating in Chinese native cattle breeds for the first time, which provide a detailed description of how diverse strains may cause skin tumour among Chinese local breed cattle therefore critical for further epidemiological study of relevant diseases.