Abstract
This study aims to investigate the genomic epidemiological characteristics of enteric adenovirus types F40 and F41 circulating in Yantai from August 2022 to August 2023, with a focus on genetic diversity, recombination events, and their potential implications for public health and vaccine development. A total of 1200 stool specimens were collected from patients with suspected viral diarrhea, and 47 human adenovirus F subgroup positive samples in Yantai were analyzed. HAdV-F subgroup nucleic acid detection and whole-genome sequencing were performed to identify virus types and single nucleotide variants (SNVs). Phylogenetic and recombination analyses were conducted, and viral protein structures were predicted using AlphaFold3. HAdV-F40 strains exhibited relative genetic conservation, with mutations primarily localized to the fiber gene. In contrast, HAdV-F41 strains displayed pronounced genetic divergence, with a higher mutation burden in the hexon gene. Recombination analysis revealed clear intra-typic recombination events within HAdV-F41, particularly in the hexon gene region. Structural modeling indicated that although the overall protein architecture remained intact, amino acid changes in key antigenic regions may influence immune evasion. HAdV-F40 and HAdV-F41 strains circulating in Yantai show marked genetic diversity. Notably, HAdV-F41 undergoes significant recombination events that may enhance viral adaptability and immune escape. These findings provide important molecular evidence to inform future surveillance strategies and vaccine antigen design for HAdV-F subgroups.