Article ID: JJID.2017.476
Neutralization tests (NT) were routinely used for identification of human adenovirus C species (HAdV-C) in Japan until 2007. The aim of this study was to clarify serological cross-reactivity of antiserum used exclusively in Japan and describe the first identification of HAdV type 57 (HAdV-57) in Japan. Anti-HAdV serum to HAdV-1, 2, 5, and 6 was quantitatively evaluated for cross-reactivity to the HAdV-57 isolates. Anti-HAdV-6 serum neutralized HAdV-57 with 32 to 64 times higher the concentration necessary to neutralize homologous HAdV-6. HAdV-1, 2, and 5 strains were not neutralized by anti HAdV-6 serum. 28 HAdV-6 strains isolated from 6476 clinical samples were re-examined for HAdVs detected in Shimane Prefecture of Japan from 2005 to 2014. These 28 strains were re-examined by PCR-sequencing techniques using the penton, hexon, and fiber regions. Three isolates were determined to be HAdV-57. These data show that HAdV-57 had already invaded Japan as early as 2005, and that HAdV-57 strains were misidentified as HAdV-6.
