Metagenomic analysis of viromes of dromedary camel fecal samples reveals large number and high diversity of circoviruses and picobirnaviruses

The recent discovery of Middle East Respiratory Coronavirus and another novel dromedary camel coronavirus UAE-HKU23 in dromedaries has boosted interest in search of novel viruses in dromedaries. In this study, fecal samples of 203 dromedaries in Dubai were pooled and deep sequenced. Among the 7330 assembled viral contigs, 1970 were assigned to mammalian viruses. The largest groups of these contigs matched to Picobirnaviridae, Circoviridae, Picornaviridae, Parvoviridae, Astroviridae and Hepeviridae. Many of these viral families were previously unknown to dromedaries. In addition to the high abundance of contigs from Circoviridae (n=598 with 14 complete genomes) and Picobirnaviridae (n=1236), a high diversity of contigs from these two families was found, with the 14 Circoviridae complete genomes forming at least five clusters and contigs from both genogroup I and genogroup II potentially novel picobirnaviruses. Further studies comparing the incidence of these viral families in healthy and sick dromedaries will reveal their pathogenic potential.