Infecção experimental de coelhos com o isolado mutum de herpesvirus bovino 5 (BoHv-5)

Abstract

Bovine herpesvirus 5 (BoHV-5) is an alphaherpesvirus associated with meningoencephalitis, an usually fatal disease and highly prevalent in South America. In this study, we infected rabbits with a Brazilian BoHV-5 strain, named Mutum, isolated from a bovine with spinal cord symptoms, uncommon for this illness. Six animals were inoculated intranasally and two (control group) were mock infected. The rabbits were clinically monitored and submitted to blood sampling and nasal swabs. The half of the animals was euthanatized 5 days postinoculation (pi) and the remaining, in the day 12 pi. Sections of brain cortex, cerebellum, brain stem, trigeminal ganglia, cervical spinal cord, thoracic spinal cord and lumbar spinal cord were collected in two samples for virological and histological examinations. The animals of 12th day showed seizures, periods of depression or excitability and tremors crisis, started on the day 6 pi, but it was not able to cause the death in the rabbits during the experiment. Mild microscopic lesions were observed just in one of the rabbits from 12th day. Infectious virus was recovered from cortex, cerebellum, trigeminal ganglia, cervical, thoracic and lumbar spinal cord of infected animals and was spread by nasal discharge from day 5 until day 12 pi. Viral DNA was detected in the brain stem, cerebellum, cervical spinal cord and thoracic spinal cord of infected animals. To our knowledge, there are no researches that had isolated and detected virus in sections of cervical and thoracic spinal cord in experimentally or naturally infected animals with BoHV-5. These results confirm the rabbits as a suitable model to experimental infection with BoHV-5 by the intranasal route. The virus detection in the spinal cord point to the need of consider it like an appropriate material to diagnosis of BoHV-5 meningoencephalitis