A third gyrovirus species in human faeces

Abstract

Until 2011 the genus Gyrovirus in the family Circoviridae consisted of a single virus (Chicken anemia virus or CAV) causing a common immunosuppressive disease in chickens when a second gyrovirus (HGyV) was reported on the skin of 4 % of healthy humans. HGyV is very closely related to a recently described chicken gyrovirus, AGV2, suggesting that they belong to the same viral species. During a viral metagenomic analysis of 100 human faeces from children with diarrhoea in Chile we identified multiple known human pathogens (adenoviruses, enteroviruses, astroviruses, sapoviruses, noroviruses, parechoviruses and rotaviruses) and a novel gyrovirus species we named GyV3 sharing <63 % similarity with other gyrovirus proteins with evidence of recombination with CAV in its UTR. Gyroviridae consensus PCR revealed a high prevalence of CAV DNA in diarrhoea and normal faeces from Chilean children and faeces of USA cats and dogs, which may reflect consumption of CAV-infected/vaccinated chickens. Whether GyV3 can infect humans and/or chickens requires further studies.

Fig. 1.

Human faeces-associated gyroviruses. (a) Genome organizations of a novel genovirus GyV3, CAV, HGyV and AGV2. (b) Global pair-wise sequence alignments of GyV3 with CAV, HGyV and AGV2 reference strains. The sequence similarity (%) is indicated by the height of each point along the y axis. The horizontal axis shows the nucleotide positions in the complete genome. (c) Phylogenetic trees generated with VP1, VP2, VP3 proteins and UTR regions of gyroviruses detected in human faeces and other gyroviruses. The scale indicates amino acid or nucleotide substitutions per position. Note: *The UTR sequences of CL33, CL37 and CL52 were not completed due to GC-rich contents.