Genomic characterization and distribution of bovine foamy virus in Japan

Abstract

Bovine foamy virus (BFV) is distributed through worldwide cattle herds. Although the biological features of BFV are not well understood, appearance of clinical manifestation by superinfection with other microorganisms is inferred. In Japan, reports of genomic characterizations and epidemiology of this virus are limited. In this study, we performed whole genomic sequencing of BFV strains Ibaraki and No.43, which were isolated in this country. Additionally, we investigated BFV in geographically distant four daily farms in Japan, to estimate the distribution of BFV and its correlation to bovine leukemia virus (BLV). BFV was distributed throughout Japan; the average positive rate was 12.7%. The nucleotide sequence identities of the isolates were 99.6% when compared with BFV strain isolated in the USA. The phylogenetic tree using env gene sequence showed strains Ibaraki, No.43 and Kagoshima were sorted in the same cluster including the USA and Chinese strains, while Hokkaido strain was in the other cluster including European strains. Although no clear correlation between BFV and BLV could be found, BFV and BLV infections were likely to increase with ages. Our data on epidemiology and characteristics of BFV will provide important information to reveal biological features of BFV.

Molecular characterization of bovine foamy virus and its association with bovine leukemia virus infection in Vietnamese cattle

“…The prevalence of BFV infection varies widely among countries [2,3,5,11,12,14,20,23,27,33]. In the present study, out of 243 DNA samples from 67 cattle farms, only eight were positive for BFV provirus by PCR targeting to pol gene, whereas PCR targeting gag gene identified ten as positive.…”

“…The BFV genome is composed of gag, pol, and env structural genes flanked by the long terminal repeats (LTRs) and additional accessory genes designated as tas and bet [26]. The previous results of phylogenetic analysis suggested that BFV could be classified into two distinct clades, the European clade and the non-European clade [7,9,23]. The European clade comprised the two…”

“…Besides, mice transgenic expressing the partial or complete genome of PFV were shown to develop progressive encephalopathy and myopathy [1,4].BFV was first isolated from lymphosarcomatous and apparently healthy cattle in 1969 [19]. Subsequently, BFV infection was confirmed in livestock cattle in different parts of the world [2,3,5,11,12,14,20,23,27,33]. Moreover, the previous studies showed the concomitant infection of BFV with either bovine leukemia virus (BLV) or bovine immunodeficiency virus, and suggested the presence of BFV in the host may contribute to diseases caused by other pathogens [2,12,13].The BFV genome is composed of gag, pol, and env structural genes flanked by the long terminal repeats (LTRs) and additional accessory genes designated as tas and bet [26].…”

“…Moreover, the previous studies showed the concomitant infection of BFV with either bovine leukemia virus (BLV) or bovine immunodeficiency virus, and suggested the presence of BFV in the host may contribute to diseases caused by other pathogens [2,12,13].The BFV genome is composed of gag, pol, and env structural genes flanked by the long terminal repeats (LTRs) and additional accessory genes designated as tas and bet [26]. The previous results of phylogenetic analysis suggested that BFV could be classified into two distinct clades, the European clade and the non-European clade [7,9,23]. The European clade comprised the two…”

“…European isolates, including BFV Reims and BFV 100, and the non-European clade comprising the BFV isolates from China, USA, and Japan [7,9,23].…”