Abstract

Adenoviruses are DNA viruses that are widely distributed among vertebrates. They are non-enveloped viruses, a characteristic that makes them particularly stable in the environment.¹ In California sea lions (Zalophus californianus), uncharacterized adenoviruses have been associated with hepatitis since 1979.² While it was initially assumed that these cases were caused by canine adenovirus-1, recent molecular work described a novel sea lion Adenovirus (CSLAdV-1).³ We present the genome of CSLAdV-1 and phylogenetic analysis, and development of a quantitative PCR (qPCR) assay for diagnosis and comparison of prevalence among managed and wild populations of California sea lions and other pinnipeds.

To obtain the genome of CSLAdV-1, we designed consensus primers for multiple genes and the ITR region of mast adenoviruses using laurasiatherian hosts, and closed gaps by primer walking. We obtained the complete gene complement, with a total of 32709 bp and a GC content of 36%. Phylogenetic analysis was done for five predicted proteins from the core region (pTP, penton, p100K, hexon and DNA polymerase). Protein alignments were done using MAFFT and model selection was done with ProtTest. Maximum likelihood and Bayesian analyses were then run. CSLAdV-1 clusters with bovine adenovirus B. Low GC content in viruses is often associated with recent host jumps.⁴ This may be evidence of a host jump from a cetartiodactyl host. We developed a qPCR assay for rapid, sensitive, and specific diagnosis and quantification of CSLAdV-1 among managed and wild populations of California sea lions and other pinnipeds. A total of 72 samples have been run; 62 samples from an open water managed collection and 10 from wild animals. This preliminary analysis suggests a higher prevalence of CSLAdV-1 among wild populations than this open water managed collection 0–5% v/s 10%, respectively.

Acknowledgements

This work was funded by research grant No. N00014-09-1-0252 from the Office of Naval Research to JW. The authors would like to thank the staff at The Marine Mammal Center and the Navy Marine Mammal Program for their assistance in sample collection. We would also like to thank Linda Archer and Dr. Thomas Waltzek from the University of Florida for their assistance.

* Presenting author
⁺ Student presenter

Literature Cited

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