Figure 1

An external file that holds a picture, illustration, etc.
Object name is 1471-2164-15-S5-S4-1.jpg

One-step components of a single patient. A) Largest one-step component of patient 14, where each node is a variant and two nodes are connected by a link if the nucleotide distance between them is 1. B) k-step network showing the three components of patient 14. Each one-step component is shown in a different colour and links among component connect the pairs of variants having the minimal distance found among components.

2014;15 Suppl 5:S4. doi: 10.1186/1471-2164-15-S5-S4. Epub 2014 Jul 14.

Next-generation sequencing reveals large connected networks of intra-host HCV variants.

Campo DS, Dimitrova Z, Yamasaki L, Skums P, Lau DT, Vaughan G, Forbi JC, Teo CG, Khudyakov Y.

Abstract

BACKGROUND:

Next-generation sequencing (NGS) allows for sampling numerous viral variants from infected patients. This provides a novel opportunity to represent and study the mutational landscape of Hepatitis C Virus (HCV) within a single host.

RESULTS:

Intra-host variants of the HCV E1/E2 region were extensively sampled from 58 chronically infected patients. After NGS error correction, the average number of reads and variants obtained from each sample were 3202 and 464, respectively. The distance between each pair of variants was calculated and networks were created for each patient, where each node is a variant and two nodes are connected by a link if the nucleotide distance between them is 1. The work focused on large components having > 5% of all reads, which in average account for 93.7% of all reads found in a patient.

CONCLUSIONS:

Most intra-host variants are organized into distinct single-mutation components that are: well separated from each other, represent genetic distances between viral variants, robust to sampling, reproducible and likely seeded during transmission events. Facilitated by NGS, large components offer a novel evolutionary framework for genetic analysis of intra-host viral populations and understanding transmission, immune escape and drug resistance.