Ball Python Nidovirus: a Candidate Etiologic Agent for Severe Respiratory Disease in Python regiusMark D. Stenglein, Elliott R. Jacobson, Edward J. Wozniak, James F. X. Wellehan, Anne Kincaid, Marcus Gordon, Brian F. Porter, Wes Baumgartner, Scott Stahl, Karen Kelley, Jonathan S. Towner, Joseph L. DeRisi
mBio, 2014Abstract: A severe, sometimes fatal respiratory disease has been observed in captive ball pythons (Python regius) since the late
1990s. In order to better understand this disease and its etiology, we collected case and control samples and performed pathological
and diagnostic analyses. Electron micrographs revealed filamentous virus-like particles in lung epithelial cells of sick animals.
Diagnostic testing for known pathogens did not identify an etiologic agent, so unbiased metagenomic sequencing was performed.
Abundant nidovirus-like sequences were identified in cases and were used to assemble the genome of a previously
unknown virus in the order Nidovirales. The nidoviruses, which were not previously known to infect nonavian reptiles, are a
diverse order that includes important human and veterinary pathogens. The presence of the viral RNA was confirmed in all diseased
animals (n8) but was not detected in healthy pythons or other snakes (n57). Viral RNA levels were generally highest
in the lung and other respiratory tract tissues. The 33.5-kb viral genome is the largest RNA genome yet described and shares canonical
characteristics with other nidovirus genomes, although several features distinguish this from related viruses. This virus,
which we named ball python nidovirus (BPNV), will likely establish a new genus in Torovirinae subfamily. The identification of
a novel nidovirus in reptiles contributes to our understanding of the biology and evolution of related viruses, and its association
with lung disease in pythons is a promising step toward elucidating an etiology for this long-standing veterinary disease.
