Virus discovery in dogs with neurological disease and viral encephalitis of unresolved etiology by high-throughput sequencing based metagenomics
The knowledge on infectious disease etiologies in companion animals is constantly growing; however there is still a high proportion of animals with severe disease in which the pathogen remains undetermined. This is in particular the case for infectious diseases of the nervous system. i.e of encephalitis. In this project, we applied cutting-edge sequencing technologies, so-called high-throughput- sequencing (HTS), and big data analysis by bioinformatics (metagenomics) to elucidate the origin of viral brain infections in dogs. We analyzed retrospectively brain tissue samples of dogs that showed severe neurological disease and a neuropathological disease phenotype of a virus infection (n=50), in which the cause of the disease remained undetermined. Our results revealed that the prevalence of Tick-Borne Encephalitis virus (TBEV; 16 cases), a virus transmitted by ticks, which also affects humans, is a common cause of encephalitis in dogs. We conclude that the prevalence of TBEV infection in dogs remained largely underestimated. Moreover, we found two cases of infections with canine vesivirus, a virus that has not been associated with neurological diseases so far, which will need further investigations. These results shed new light on the nature and frequency of neuroinfectious diseases in companion animal. They will ultimately contribute to improved prophylactic and therapeutic measures.
The Berne University Research Foundation provided the funding to purchase a PCR Thermocycler and a laboratory -80°C freezer. Both instruments were indispensable for this study and served for the confirmation of metagenomic viral hits by conventional PCR and sequencing techniques, and for on-site immediate and short-term storage of DNA and RNA tissue extracts.
Prof. Dr. Torsten Seuberlich
Dr. Michel C. Koch
Division of Neurological Sciences, Vetsuisse Faculty, University of Bern
