Group A Rotavirus Associated with Encephalitis in Red Fox

Abstract

In 2011, a group A rotavirus was isolated from the brain of a fox with encephalitis and neurologic signs, detected by rabies surveillance in Italy. Intracerebral inoculation of fox brain homogenates into mice was fatal. Genome sequencing revealed a heterologous rotavirus of avian origin, which could provide a model for investigating rotavirus neurovirulence.

Keywords: Italy; brain; fox; group A rotavirus; meningitis/encephalitis; neurologic disease; rotavirus; viruses.

Figure 1

Images of brain of fox with group A rotavirus infection and brains of suckling and weanling mice inoculated with fox brain homogenates. A, B) Negative-staining electron microscopy. Presence of virions morphologically related to family Reoviridae from fox (A) and mouse (B) brain (arrows). Scale bar in panel A indicates 200 nm; in panel B, 100 nm. C, D) Histologic and immunohistochemical appearance of the cerebral cortex of the fox. C) Perivascular cuffing of inflammatory cells in the brain stained by hematoxylin and eosin (original magnification ×10). D) Viral antigen in the cytoplasm of neurons (immunohistochemistry, original magnification ×20). E) Foci with rounding cells of the confluent monolayers of Marc-145 cells infected with the brain homogenate from mouse at 2 days after inoculation (original magnification ×40). F) Mock cells (original magnification ×40).

Figure 2

Phylogenetic analysis of RVA strain fox-288356. Analysis was performed on the basis of the concatenated nucleotide sequences of genomic segments. Fox- 288356 is correlated with RVA PO-13 (from pigeon) and clustered with the avian RVA. Reference sequences are identified by strain name and GenBank accession number. Scale bar indicates nucleotide substitutions per site. RVA, group A rotavirus; RVB, group B rotavirus.