Whole genome sequencing of human enteroviruses from clinical samples by nanopore direct RNA sequencing

Enteroviruses are small RNA viruses that affect millions of people each year by causing an important burden of disease with a broad spectrum of symptoms. In routine diagnostic laboratories, those viruses are identified by PCR based methods, often combined with partial sequencing for genotyping. In this proof-of-principle study, we assessed direct RNA sequencing (DRS) using nanopore sequencing technology for fast whole-genome sequencing of viruses directly from clinical samples. Results of the approach were complemented with those obtained by sequencing the corresponding viral cDNA via Illumina MiSeq sequencing. DRS of total RNA extracted from three different enterovirus-positive stool samples produced long RNA fragments, covering between 59% to 99.6 % of the best reference genomes. The identification of the enterovirus sequences in the sample was confirmed by the short-read cDNA sequencing. Sequence identity between DRS and Illumina MiSeq enterovirus consensus sequences ranged between 94-97%. Here we show that nanopore DRS can be used to correctly identify the genotypes of enteroviruses from patient stool samples with high viral load.