Complete Genome Analysis Of A Novel Intertypic Recombinant Human Adenovirus Causing Epidemic Keratoconjunctivitis In Japan

Abstract

Purpose: : Epidemic keratoconjunctivitis (EKC) is caused by human adenovirus (HAdV), mainly HAdV-8, -19, -37, -53 and -54. However, 11 untyped adenoviral samples were isolated from the EKC patients in Japan in the past 3 years. In the present study, we determined the complete genome sequence of the 2307-S strain, one of those samples. The characteristics of the entire genome of 2307-S strain were analyzed. Then, its complete sequences were compared with those of other HAdV-Ds.

Methods: : The complete HAdV genome sequences of 2307-S strain were determined by PCR-based sequencing method. Multiple alignments were performed and analyzed using ClustalW software. The mVISTA Limited Area Global Alignment of Nucleotides (LAGAN) tool was used for global pairwise sequence alignments to align and compare the sequences of paired complete HAdV genomes.

Results: : HAdV genome contains 4 variable regions, hexon, penton base, fiber genes, and early trascription unit 3 (E3). The nucleotide sequence of loop1 and 2 in the hexon of 2307-S showed high identity with those of the HAdV-15 and -29 prototype strains. The fiber and E3 regions showed high identity with HAdV-9. The penton showed high identity with HAdV-9 and -26. Thus, 2307-S strain was a recombinant virus between HAdV-9, -15, -26, -29 and/or other HAdVs.

Conclusions: : We propose that the 2307-S strain is a novel intertypic recombinant adenovirus, HAdV-15/29/H9. It may be one of the recent etiological agents of EKC.

Keywords: adenovirus • conjunctivitis • genetics