Two Novel Alphaherpesviruses Associated With Fatal Disseminated Infections in Atlantic Bottlenose Dolphins

Abstract

Two immature female bottlenose dolphins (Tursiops truncatus) were found stranded on the Atlantic coast of the USA. Necropsy and histopathologic examination of both dolphins demonstrated acute necrotizing lesions in multiple organ systems. Commonly seen in these lesions were cells with enlarged nuclei that contained single 4 to 6 m diameter homogeneous eosinophilic inclusion bodies that were often surrounded by a clear halo. Ultrastructural examination revealed that intranuclear inclusions contained 90 to 110 nm diameter viral particles with electron-dense cores and hexagonal profiles. Viral particles were also present in the cytoplasm, and these were surrounded by variably electron-dense envelopes. Enveloped virions were 140 nm in diameter. Polymerase chain reactions targeting the DNA polymerase and terminase genes of herpesviruses were carried out on unfixed tissues of both animals, and analysis of the DNA products indicated the presence of two novel alphaherpesviruses. The gross, histologic, ultrastructural, and molecular genetic findings indicate disseminated herpesviral infections, and support the conclusion that the alphaherpesviruses caused the deaths of the two dolphins. This is the first report of disseminated herpesviral infection in cetaceans.

A Novel Gammaherpesvirus Associated with Genital Lesions in a Blainville's Beaked Whale (Mesoplodon densirostris)

“…Comparisons with homologous sequences obtained from the GenBank database using the Gap function of the GCG software demonstrated that the Blainville's beaked whale herpesvirus DNA polymerase gene fragment was most closely related to the California sea lion gammaherpesvirus, with which it shared identities of 58.8% and 61.9% at the nucleotide and amino acid levels, respectively. Similar comparisons to the only two GenBank-deposited homologous sequences from cetacean alphaherpesviruses (Blanchard et al, 2001) uncovered identities of 48.9% and 36.8% at the nucleotide and amino acid levels, respectively, for one virus (GenBank accession number AF196646), and 40.8% and 34.5% for the second virus (AF245443). The herpesvirus DNA polymerase gene fragment sequence of the Blainville's beaked whale has been deposited in the GenBank database under accession number AY803337.…”

“…This virus is tentatively designated Ziphiid herpesvirus type 1 (ZHV-1). The ZHV-1 is clearly distinct from two previously identified alphaherpesviruses of cetaceans (Atlantic bottlenose dolphins) that were associated with fatal disseminated infections (Blanchard et al, 2001), as shown by nucleotide and amino acid sequence analysis, and by its clading with other members of the Gammaherpesvirinae subfamily on the phylogenetic tree (Fig. 3).…”

“…Herpesvirus or herpes-like infections have been associated with encephalitis in a harbor porpoise (Phocoena phocoena) in Sweden (Kennedy et al, 1992), dermatitis in a beluga whale (Delphinapterus leucas) in Canada (Martineau et al, 1988;Barr et al, 1989), and skin lesions in dusky dolphins (Lagenorhynchus obscurus) in the South Pacific (Van Bressem et al, 1994). Recently two apparently distinct alphaherpesviruses were found to be associated with fatal disseminated infections in two Atlantic bottlenose dolphins (Tursiops truncatus) off the east coast of the USA (Blanchard et al, 2001). This report describes the detection of a novel gammaherpesvirus in a genital lesion from a stranded Blainville's beaked whale (Mesoplodon densirostris).…”

HERPESVIRUS-ASSOCIATED GENITAL LESIONS IN A STRANDED STRIPED DOLPHIN (STENELLA COERULEOALBA) IN THE CANARY ISLANDS, SPAIN

“…Molecular studies also have described alphaherpesviruses associated with fatal systemic infections in two Atlantic bottlenose dolphins (Blanchard et al 2001), a localized infection of the lymphoid system in a Cuvier's beaked whale (Ziphius cavirostris; Arbelo et al 2010), and acute multifocal necrotizing tubulointerstitial nephritis in a Blainville's beaked whale (Arbelo et al 2012). …”

Herpes-like Virus Infection in Yangtze Finless Porpoise (Neophocaena phocaenoides): Pathology, Ultrastructure and Molecular Analysis

“…Herpesviruses are also commonly found in marine dolphins (Blanchard et al, 2001;Smolarek Benson et al, 2006). A recent study was conducted of the molecular epidemiology of herpesvirus infection in long-finned pilot whales and striped dolphins (Belliè re et al, 2010).…”