Hybrid sequencing for detailed genetic characterization of human adenoviruses

Abstract Human adenoviruses (HAdVs) are highly contagious and have significant clinical implications in the pediatric population. In the present study, we employed a combination of long-read sequencing and short-read sequencing to accurately reconstruct 32 genomes of HAdVs. The phylogenetic analyses based on the whole genome and genes revealed distinct sub-clusters within HAdV-B and -E. For HAdV-C, the phylogenetic trees constructed from hexon, fiber, and E3 gene sequences consistently matched the whole-genome phylogeny, reflecting the high sequence diversity in these regions. Notably, in regions with high sequence diversity, we observed a higher number of recombination breakpoints and lower GC content. Additionally, the E4 gene region of HAdV-C exhibited a Ka/Ks ratio > 1, indicating that positive selection may be driving the fixation of advantageous mutations. These genetic characterization analyses are crucial for enhancing future surveillance of HAdVs, facilitating a more strategic and proactive approach to monitoring their evolution, diversity, and epidemiological trends.