RESPIRATORY AND PHARYNGOESOPHAGEAL IRIDOVIRUS INFECTION IN A GOPHER TORTOISE (GOPHERUS-POLYPHEMUS)

A free-living adult male gopher tortoise (Gopherus polyphemus) was fou nd on Sanibel Island, Florida (USA), on 18 February 1992 with signs of upper respiratory disease. On necropsy after euthanasia on 27 Februar y 1992, severe, extensive necrotizing ulcerative tracheitis, multifoca l necrotizing pneumonia, and multifocal necrotizing ulcerative pharyng itis and esophagitis were observed. Large ovoid to round intracytoplas mic basophilic inclusions, which appeared to displace the nucleus to t he cell periphery, occurred within degenerate and necrotic epithelial cells of the above tissues, On transmission electron microscopy of for malin-fixed trachea and lung, intracytoplasmic viral particles were ob served within necrotic cells in the tracheal lumen and epithelial cell s of the lung. Most infected cells also had a roughly spherical granul ar cytoplasmic inclusion that contained clusters of viral particles. V iral particles had an electron dense spherical to icosahedral core sur rounded by a less electron dense icosahedral capsid. Mature extracellu lar virions mere surrounded by an envelope and were 150 to 220 nm in d iameter, Virions and cytoplasmic inclusions were morphologically simil ar to those of the Family Iridoviridae.