Evaluation of A Single-reaction Method for Whole Genome Sequencing of Influenza A Virus using Next Generation Sequencing

Objective To evaluate a single-reaction genome amplification method, the multisegment reverse transcription-PCR(M-RTPCR), for its sensitivity to full genome sequencing of influenza A virus, and the ability to differentiate mix-subtype virus, using the next generation sequencing(NGS) platform. Methods Virus genome copy was quantified and serially diluted to different titers, followed by amplification with the M-RTPCR method and sequencing on the NGS platform. Furthermore, we manually mixed two subtype viruses to different titer rate and amplified the mixed virus with the M-RTPCR protocol, followed by whole genome sequencing on the NGS platform. We also used clinical samples to test the method performance. Results The M-RTPCR method obtained complete genome of testing virus at 125 copies/reaction and determined the virus subtype at titer of 25 copies/reaction. Moreover, the two subtypes in the mixed virus could be discriminated, even though these two virus copies differed by 200-fold using this amplification protocol. The sensitivity of this protocol we detected using virus RNA was also confirmed with clinical samples containing low-titer virus. Conclusion The M-RTPCR is a robust and sensitive amplification method for whole genome sequencing of influenza A virus using NGS platform.