Paramyxovirus Infection in Caiman Lizards (Draecena Guianensis)

Abstract

Abstract. Three separate epidemics occurred in caiman lizards (Dracaena guianensis) that were imported into the USA from Peru in late 1998 and early 1999. Histologic evaluation of tissues from necropsied lizards demonstrated a proliferative pneumonia. Electron microscopic examination of lung tissue revealed a virus that was consistent with members of the family Paramyxoviridae. Using a rabbit polyclonal antibody against an isolate of ophidian (snake) paramyxovirus, an immunoperoxidase staining technique demonstrated immunoreactivity within pulmonary epithelial cells of 1 lizard. Homogenates of lung, brain, liver, or kidney from affected lizards were placed in flasks containing monolayers of either terrapene heart cells or viper heart cells. Five to 10 days later, syncytial cells formed. When Vero cells were inoculated with supernatant of infected terrapene heart cells, similar syncytial cells developed. Electron microscopic evaluation of infected terrapene heart cells revealed intracytoplasmic inclusions consisting of nucleocapsid strands. Using negative-staining electron microscopy, abundant filamentous nucleocapsid material with a herringbone structure typical of the Paramyxoviridae was observed in culture medium of infected viper heart cells. Seven months following the initial epizootic, blood samples were collected from surviving group 1 lizards, and a hemagglutination inhibition assay was performed to determine presence of specific antibody against the caiman lizard isolate. Of the 17 lizards sampled, 7 had titers of Յ1:20 and 10 had titers of Ͼ1:20 and Յ1:80. This report is only the second of a paramyxovirus identified in a lizard and is the first to snow the relationship between histologic and ultrastructural findings and virus isolation.

Avian Paramyxoviruses: Detection by Transmission Electron Microscopy Techniques

“…The presence of intracytoplasmatic and intranuclear inclusions, surrounded by a membrane and containing viral nucleocapsid are in accordance with other authors who used the resin embedding technique (Mannl et al, 1987;Granzow et al, 1999;Jacobson et al, 2001). …”

Mesothelial metaplasia in European pond turtle, Emys orbicularis (Testudines: Emydidae) infected with Spiroxys contortus (Nematoda: Spirurida)

“…larval forms of cestodes like plerocercoids, "Tetrathyridium" or "Sparganum") induce metaplasia to a cuboidal or columnar type resembling epithelium (Julian, 1985). In reptiles, the hypertrophy and proliferation of mesothelial cells have been observed in viral infections with paramyxoviruses in caiman lizards (Dracaena guianensis) (Jacobson et al, 2001). Granulomatous inflammation and activation of mesothelial cells have been also observed following intraperitoneal implants that generate chronic focal irritation (hormonal implants or implant transmitters) (Goodwin & Grizzle, 1991;Gray et al, 2005).…”

Molecular Diagnosis of Paramyxovirus Infection in Snakes Using Reverse Transcriptase–Polymerase Chain Reaction and Complementary Deoxyribonucleic Acid:Ribonucleic Acid in Situ Hybridization

“…Hemagglutination and hemagglutination inhibition have been used to diagnose OPMV infection, but these techniques require more time. 3,12 In contrast, RT-PCR can rapidly and specifically verify viral infection, provided contamination of the samples is avoided.…”

“…Immunodiagnostic techniques include hemagglutination, hemagglutination inhibition, and determination of antibody titers on paired serum specimens. 12 The presence of an OPMV antibody titer indicates exposure to the virus; however, continued infection, progressive infection, or recovery cannot be determined without paired sera.…”

“…11,12 Virus isolation in Vero cell cultures is practical but is relative costly and labor-intensive. Immunodiagnostic techniques include hemagglutination, hemagglutination inhibition, and determination of antibody titers on paired serum specimens.…”