Out of the reservoir: Phenotypic and genotypic characterization of a novel cowpox virus isolated from a common vole

• Published in: Journal of Virology
• Main Authors: Hoffmann, Donata, Franke, A., Jenckel, Maria, Tamošiūnaitė, A., Schluckebier, Julia, Granzow, Harald, Hoffmann, Bernd, Fischer, Stefan, Ulrich, Rainer, Höper, Dirk, Goller, Katja, Osterrieder, N., Beer, Martin
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2015
• Subjects: article; Text; ddc:570; Common vole
• Online Access: https://doi.org/10.1128/JVI.01195-15; https://www.openagrar.de/receive/openagrar_mods_00016548; https://www.openagrar.de/servlets/MCRFileNodeServlet/Document_derivate_00012669/SD2015299.pdf; http://jvi.asm.org/content/89/21/10959; http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4621121/

The incidence of human cowpox virus (CPXV) infections has increased significantly in recent years. Serological surveys have suggested wild rodents as the main CPXV-reservoir. We characterized a CPXV isolated during a large scale screening from a feral common vole. A comparison of the full-length DNA-sequence of this CPXV-strain with a highly virulent pet rat CPXV-isolate showed a sequence identity of 96%, including a large additional ORF of about 6,000 nucleotides, which is absent in the reference CPXV-strain Brighton Red. Electron microscopy analysis demonstrated that the vole isolate, in contrast to the rat strain, forms A-type inclusion bodies (ATI) with incorporated virions, consistent with the presence of complete ati and p4c genes. Experimental infections showed that the vole CPXV-strain caused only mild clinical symptoms in its natural host, while all rats developed severe respiratory symptoms followed by a systemic rash. In contrast, common voles infected with a high dose of the rat CPXV showed severe signs of respiratory disease but no skin lesions, whereas infection with a low dose led to virus excretion with only mild clinical signs. We concluded that the common vole is susceptible to infection with different CPXV-strains. The spectrum ranges from well-adapted viruses causing limited clinical symptoms to highly virulent strains causing severe respiratory symptoms. In addition, the low pathogenicity of the vole isolate in its eponymous host suggests a role of common voles as a major CPXV reservoir, and future research will focus on the correlation between viral genotype and phenotype/pathotype in accidental and reservoir species.