Abstract

A novel member of the parainfluenza virus family was identified in a bottlenose dolphin (Tursiops truncatus) with upper respiratory disease. The virus was isolated from three antemortem left lung aspirates and two postmortem samples. The morphology of the virions on negative and transmission electron microscopy was consistent with that of paramyxoviruses. Two genomic fragments, comprising 532 and 473 nucleotides from the open reading frames that code for the viral polymerase and fusion protein, respectively, were amplified by polymerase chain reaction using generic primers. Phylogenetic analyses of the two viral RNA segments showed that the isolate comprised a novel virus strain, tentatively named Tursiops truncatus Parainfluenza virus 1 (TtPIV1). The virus is monophyletic with, but genetically distinct from, the various bovine parainfluenza virus 3 strains.

Parainfluenza viruses are commonly found in terrestrial mammals, including cattle, deer, dogs, guinea pigs, humans, and mice; and are one of most frequent causes of common colds in children, kennel cough in dogs, and upper respiratory tract infections in cattle. In general, infections in adult animals are usually asymptomatic or mild, while more severe infections may occur with secondary bacterial infections in neonatal, young, and immunocompromised animals.

Further surveillance is needed to determine the clinical significance and prevalence of TtPIV1 in bottlenose dolphin populations.

Acknowledgements

The authors would like to thank Dr. Pam Yochem at Hubbs-SeaWorld Research Institute and Dr. Judy St. Leger at SeaWorld, Inc. for their assistance with this project. This work was funded by research grant No. N00014-06-1-0250 from the Office of Naval Research to H.N. All sample collection protocols were approved by the University of Florida Institutional Animal Care and Use Committee (IACUC# C233).