Research of the Genetic Diversity of TT Viruses in Bulgaria

Abstract

Torque teno viruses (TTVs) are a member of the newly formed family Anelloviridae and contain single stranded circular DNA genome. It is believed that these viruses chronically infect people of any age, yet it is not clear what is their pathogenic potential. Our previous research has shown spread of TT viruses at least 61.87% in voluntary blood donors, 62.74% in patients with respiratory diseases, 65.21% in cases of hepatitis, 62.96% in unknown cases of pathology, 66.66% in patients with brain tumour and 64.28% in patients with renal transplantation. It was the first report demonstrating TT viruses in Bulgaria. The purpose of this work is identification of the main genotypes of TT viruses circulating in Bulgaria. The original viral DNA was isolated from blood samples from clinically healthy blood donors, a HBsAg positive sample and a patient with unexplained febrile condition. Phylogenetic tree analysis shows that most of our sequences are genetically related, highly correlated, and fall into a single cluster. The analysis shows that they are close relatives and most likely have a common ancestor. Part of the sequences could also be a separate cluster or the start of a new clone within that cluster, together with the reference sequences clustered by literature data in genotype 1.