Bovine enterovirus 2: complete genomic sequence and molecular modelling of a reference strain and a wild-type isolate from endemically infected US cattle

Abstract

Bovine enteroviruses are members of the family Picornaviridae, genus Enterovirus. Whilst little is known about their pathogenic potential, they are apparently endemic in some cattle and cattle environments. Only one of the two current serotypes has been sequenced completely. In this report, the entire genome sequences of bovine enterovirus 2 (BEV-2) strain PS87 and a recent isolate from an endemically infected herd in Maryland, USA (Wye3A) are presented. The recent isolate clearly segregated phylogenetically with sequences representing the BEV-2 serotype, as did other isolates from the endemic herd. The Wye3A isolate shared 82 % nucleotide sequence identity with the PS87 strain and 68 % identity with a BEV-1 strain (VG5-27). Comparison of BEV-2 and BEV-1 deduced protein sequences revealed 72-73 % identity and showed that most differences were single amino acid changes or single deletions, with the exception of the VP1 protein, where both BEV-2 sequences were 7 aa shorter than that of BEV-1. Homology modelling of the capsid proteins of BEV-2 against protein database entries for picornaviruses indicated six significant differences among bovine enteroviruses and other members of the family Picornaviridae. Five of these were on the 'rim' of the proposed enterovirus receptor-binding site or 'canyon' (VP1) and one was near the base of the canyon (VP3). Two of these regions varied enough to distinguish BEV-2 from BEV-1 strains. This is the first report and analysis of full-length sequences for BEV-2. Continued analysis of these wild-type strains should yield useful information for genotyping enteroviruses and modelling enterovirus capsid structure.

Survey of Bovine Enterovirus in Biological and Environmental Samples by a Highly Sensitive Real-Time Reverse Transcription-PCR

“…on April 29, 2019 by guest http://aem.asm.org/ significant sequence variation in the 5ЈNCR found among BEV isolates (8,14). This variation is similar to that described for other enteroviruses that exhibit levels of identity between isolates ranging from 70 to 96% (28).…”

“…BEV is very stable in the environment, and thus, it has been proposed that this virus could be a useful indicator of water and environmental contamination (14), as well as a potential surrogate for other highly infectious picornaviruses, such as foot-and-mouth disease virus, in order to optimize extraction and/or detection procedures for contamination of the environment (8,34). The first description of the genetic relationship between simultaneously collected water and fecal samples from a single closed herd showed that in most cases, the sequences detected in water samples were quite similar to those present in feces (14).…”

“…Infection with BEV does not cause serious animal health problems, and it is usually asymptomatic; however, viruses are excreted in feces in large amounts. The usefulness of BEV detection for tracking bovine fecal contamination of environmental waters after reverse transcription (RT)-PCR amplification of BEV RNA from feces and water samples has recently been demonstrated (8,14). Further nucleotide sequencing of the amplified products allowed characterization of the detected strains circulating in the area studied, the Chesapeake Bay region of Maryland.…”

Fatal Ulcerative and Hemorrhagic Typhlocolitis in a Pregnant Heifer Associated with Natural Bovine Enterovirus Type-1 Infection

“…10,15,18,19 Because of the unavailability of type specific antisera or a commercially available diagnostic test, a genotypic classification, which supports previous recognized serological distinctions, has been proposed. 7 Despite the large volume of information available on other enteroviruses, very little documentation exists on the pathogenesis of BEV infections in cattle or on its prevalence in North America. Several case reports in the 1950s and 1970s document the isolation of BEV from feces and various tissues from apparently healthy animals or from animals with clinical signs that ranged from mild to moderate diarrhea to reproductive disease.…”

“…5). 5,7,12 Nucleotide sequence analysis of the 5'UTR and partial VP4 region (nucleotides 1-1000) revealed a 85.5% sequence identity with the UK BEV-1 VG527 strain and 77.8 to 80.7% identity with the Australian BEV-1 isolates, compared to 77.5 to 78% nucleotide identity with the US BEV-2 isolates. Analysis of a much smaller region of the 5'UTR including the 385 nucleotides of the US BEV1-261 isolate (originally isolated in Washington state in 1957) revealed an 87.1% nucleotide sequence identity (data not shown).…”