Objective To analyze the genetic characteristics of a recombinant strain of human adenovirus 5 and 89 (LN2017022) isolated from the stool sample of an acute flaccid paralysis (AFP) case in Liaoning province in 2017, and provide theoretical evidence for human adenovirus surveillance and vaccine development.

Methods The genome sequence of the LN2017022 strain was sequenced. Then, phylogenetic trees based on the whole genome, Penton base, Hexon, Fiber, and E3 gene sequences were constructed using the Neighbor-Joining (NJ) method in software MEGA 7.0 for analysis on the nucleotide and amino acid mutations of LN2017022 based on 27 full genome sequences of human adenovirus 5 (HAdV-c5) downloaded from GenBank. Recombination analysis on LN2017022 strain was performed using RDP 4.0 and SimPlot 3.5.1.

Results The whole genome length of LN2017022 strain was 35 854 bp. It had the same amino acid deletions (A363 and P364) as HAdV-89 on the RGD loop of the Penton base, and a unique amino acid mutation (P153H) on HVR1 differed from HAdV-89. Compared with HAdV-C5 prototype, the Hexon gene had only one unique mutation (C1176T) at locus 1176, which was a synonymous mutation. The Fibre gene was highly conserved. LN2017022 strain was a new recombinant genotype of P89H5F5. The phylogenetic analysis on the fill genome demonstrates that HAdV-5 can be divided into to 2 lineages, 1 and 2, and lineage 1 has 3 clades, and LN2017022 belonged to clade 2, but the genotype belonged to HAdV-C89, indicating that intra group recombination occurred in the HAdV-5 strain.

Conclusions The genome of human adenovirus type 5 has underwent significant genetic variation and recombination, and the surveillance and research of HAdV-C5-caused disease should be strengthened in the future.