Abstract

Adenoviruses have a wide host range and are common pathogens in vertebrates. In cetaceans, adenoviruses have only rarely been detected and correlated with disease. A novel adenovirus was recently detected in captive bottlenose dolphin (Tursiops truncates) suffering from self-limiting gastroenteritis. The initial analysis of partial pol and hexon gene sequences indicated that this was a hitherto unknown adenovirus with less than 80% sequence identity to previously published sequences. The aim of this study was to further genetically characterize this novel adenovirus using a high-throughput sequencing approach for whole-genome sequencing. Fecal samples from affected bottlenose dolphins were collected as previously described. Samples were homogenized and centrifuged through filters with 0.22 μm pores. To remove non-viral DNA the filtrate was treated with DNase and RNase prior to DNA extraction. Nextera XT sequencing libraries were sequenced at the MiSeq platform. Sequence reads were assembled using the MIRA assembler. The longest contigs were used to identify the most similar reference genome using BLASTn. To generate a draft consensus sequence, matching contigs were aligned against the reference genome using CodonCode Aligner software. The complete genome sequence was verified using PCR and Sanger sequencing. The analysis of phylogenetic relationships was conducted in MEGA 5 [2]. Gene prediction and annotation were used using PROKKA, MAKER and GeneMark.hmm with heuristic models. High-throughput sequencing allowed the recovery of the complete sequence of Bottlenose dolphin Adenovirus-1 (BdAdV-1). The sequence is 34 040bp and has an ITR of about 220bp. A total of 26 coding sequences were identified out of which 3 were assigned as hypothetical and 23 were functionally annotated. The homology analysis indicates that the most similar genome is the Bottlenose dolphin Adenovirus 2 (KR024710) (71% identity), followed by the California sea lion adenovirus 1 (KJ563221), and then Bovine adenovirus type 2 (AF252854). We here describe the complete sequence of a recently identified adenovirus associated with gastroenteritis in dolphins. This virus is clearly different from previously published adenoviruses, demonstrating less than 72% sequence identity. A more in-depth analysis of the obtained sequence data and predicted proteins should allow predictions to be made regarding e.g. tropism. The study also demonstrate the usefulness of high-throughput sequencing to obtain full-length genomes of genetically divergent viruses.

Published in

Title: Xth International Congress for Veterinary Virology, Viruses in a Changing World, August 31st-September 3rd 2015, Le Corum, Montpellier, France
Publisher: Cirad

Conference

Virus Genomics and Evolution Xth International Congress of Veterinary Virology (ESVV) "Changing viruses in a Changing worldAugust 31st-September 3rd 2015, Le Corum, Montpellier, France

SLU Authors

• Malmberg, Maja

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Belak, Sandor

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Granberg, Fredrik

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Infectious Medicine
Pathobiology
Medical Bioscience


Permanent link to this page (URI)

https://res.slu.se/id/publ/79490