Simultaneous urogenital infection with novel upsilonpapillomaviruses and varicellovirus monodontidalpha1 in beluga whales Delphinapterus leucas from Bristol Bay, Alaska, USA.

Abstract

Understanding the role of environmental factors such as pollution and infectious diseases on the health and well-being of free-ranging beluga whales Delphinapterus leucas is essential for their conservation. As part of this effort, 2 novel papillomaviruses (PVs) were identified in urogenital swabs of 2 free-ranging female beluga whales in Bristol Bay, Alaska, USA. Their genomes were 7825 and 7713 nucleotides (nt) in length with 84.6% nt and 82.5% amino acid identities for the L1 gene, generally used for classifying papillomaviruses. Both PV genomes contained an early region of E6, E1, E2 and E4 genes, a late region containing L2 and L1 genes, and a non-coding regulatory region. The carboxy end of the E6 oncoprotein of both PVs did not contain the PDZ-binding motif, known to have a strong correlation with oncogenicity. BLAST NCBI nt analyses of the L1 gene of 1 PV revealed highest identity (91.2%) with a PV of a short-beaked common dolphin Delphinus delphis, while the other PV showed highest identity (85.5%) with a PV from a Yangtze River finless porpoise Neophocaena asiaeorientalis. The PVs identified in this study share the highest identity with PV members of the genus Upsilonpapillomavirus, subfamily Firstpapillomavirinae, family Papillomaviridae. Also, 2 herpesviruses were isolated in primary beluga whale kidney cell cultures and identified by sequencing the glycoprotein B and E genes. Both herpesviruses corresponded to the species Varicellovirus monodontidalpha1. Our findings confirm the necessity to expand studies on the occurrence, dissemination and virus diversity that may be adversely affecting the well-being and preservation of beluga whales in Alaska.