Complete genome analysis of three live attenuated Rinderpest virus vaccine strains derived through serial passages in different culture systems

Novel cetacean morbillivirus in a rare Fraser's dolphin (Lagenodelphis hosei) stranding from Maui, Hawai'i

Cetacean morbillivirus (CeMV) is a global threat to cetaceans. We report a novel morbillivirus from a Fraser’s dolphin (Lagenodelphis hosei) that stranded in Maui, Hawaii in 2018 that is dissimilar to the beaked whale morbillivirus previously identified from Hawaii and to other CeMV strains. Histopathological findings included intranuclear inclusions in bile duct epithelium, lymphoid depletion, rare syncytial cells and non-suppurative meningitis. Cerebellum and lung tissue homogenates were inoculated onto Vero.DogSLAMtag cells for virus isolation and cytopathic effects were observed, resulting in the formation of multinucleated giant cells (i.e., syncytia). Transmission electron microscopy of infected cell cultures also revealed syncytial cells with intracytoplasmic and intranuclear inclusions of viral nucleocapsids, consistent with the ultrastructure of a morbillivirus. Samples of the cerebellum, lung, liver, spleen and lymph nodes were positive for morbillivirus using a reverse transcription-polymerase chain reaction. The resulting 559 bp L gene sequence had the highest nucleotide identity (77.3%) to porpoise morbillivirus from Northern Ireland and the Netherlands. The resulting 248 bp P gene had the highest nucleotide identity to porpoise morbillivirus in Northern Ireland and the Netherlands and to a stranded Guiana dolphin (Sotalia guianensis) in Brazil (66.9%). As Fraser’s dolphins are a pelagic species that infrequently strand, a novel strain of CeMV may be circulating in the central Pacific that could have additional population impacts through transmission to other small island-associated cetacean species.

Full genome sequencing of archived wild type and vaccine rinderpest virus isolates prior to their destruction

When rinderpest virus (RPV) was declared eradicated in 2011, the only remaining samples of this once much-feared livestock virus were those held in various laboratories. In order to allow the destruction of our institute's stocks of RPV while maintaining the ability to recover the various viruses if ever required, we have determined the full genome sequence of all our distinct samples of RPV, including 51 wild type viruses and examples of three different types of vaccine strain. Examination of the sequences of these virus isolates has shown that the African isolates form a single disparate clade, rather than two separate clades, which is more in accord with the known history of the virus in Africa. We have also identified two groups of goat-passaged viruses which have acquired an extra 6 bases in the long untranslated region between the M and F protein coding sequences, and shown that, for more than half the genomes sequenced, translation of the F protein requires translational frameshift or non-standard translation initiation. Curiously, the clade containing the lapinised vaccine viruses that were developed originally in Korea appears to be more similar to the known African viruses than to any other Asian viruses.