Sanitary surveillance of bovine encephalitis: bovine papillomavirus as causative agent

Abstract

The Laboratory of anatomopathology of Instituto Biologico/SP is authorized by the Brazilian Ministry of Agriculture (MAPA) to perform the histopathological differential diagnosis of encephalitis and Bovine Spongiform Encephalopathy. From January 2004 to October 2013 were examined by histopathology 2.603 Central Nervous System (CNS) from cattle with neurological syndrome and negative to rabies (direct immunofluorescence), where 18.2% (473) presented lesions, and the inespecific non-purulent meningoencephalitis (INPME) was the most frequent - 83.5% (395), characterized by mononuclear inflammatory infiltrate, what may indicate viral infection, showing that is necessary to search other causal agents, more else than those usually known as CNS pathogens, once there are animals with INPME that are negative to viruses. The Bovine Papillomavirus (BPV) is epitheliotropic and oncogenic, causing usually papilloma in skin and tumors in the digestive and reproductive system of bovine. Some case reports of papilloma in the CNS of bovine were published, and these tumors were located in the choroid plexus of the third ventricle, and in meninges, but these papers described only macro and microscopy, not investigating if the DNA of BPV was associated or not to lesions, in natural conditions, despite other papers had reported that BPV, when inoculated experimentally into calves meninges, had developed meningioma. The choroid plexus, meninges and skin are derivate from ectoderm, demonstrating BPV tropism for these tissues. The present study will investigate Bovine Papillomavirus (BPV) in bovine CNS samples sent to Instituto Biológico in order to perform the differential diagnosis of neurological syndrome, by the association of histological lesions to BPV positive PCR samples. The genomic sequencing will be performed in order to study the viral phylogeny of the BPV, and to associate genotypes to different lesions. (AU)