Molecular Epidemiology of Adenovirus Type 37 Isolated in Sapporo, Japan in 1990-2001

Abstract

Abstract: : Purpose: Adenovirus (AdV) type 37 is one of the major causative virus inducing epidemic keratoconjunctivitis(EKC), and most frequently isolated serotype in patients with EKC in Japan in recent years. In this study we attempted to clarify the genome type of AdV-37 isolated in Sapporo, Japan during 1990-2001. Methods: Forty-eight isolates of AdV-37 were examined. All were isolated from patients with EKC in Sapporo between 1990 and 2001. Forty-six strains isolated from 1990 to 1999 were kindly provided by Dr. Fujita in Sapporo City Institute of Public Health. All isolates were analyzed by DNA restriction analysis. The genetic relationship of the AdV-37 isolates was also examined based on the complete sequence of the fiber region and the 916-bp partial sequences of the 3'-hexon region. Results: 1. By DNA restriction analysis, eight genome types, D1 (prototype like strain), D3, D6 to D11 were identified. D1, D3 and D8 were previously reported genome types and the rest of five were new genome types. 2. Major genome type isolated changed every one or two years, D1 - D3 - D7 - D6 - D8 - D10 in order. 3. Three types of 916-bp hexon gene, h1 to h3 and four types of fiber gene, f1 to f4 were identified by DNA sequence. Each genome type was devided by pairing hexon and fiber gene type. However the sequence of both hexon and fiber genes was identical between D3 and D7, and between D8 and D9. Therefore, we could not classify these genome types by the DNA sequence of partial hexon gene and fiber gene. Conclusions: Major genome type of AdV-37 isolated changed every one or two years. In Sapporo, epidemic of AdV-37 occurred in 1991, 1994 to 1995, and 2000. The genome types were D1 and D3 in 1991, D6 and D8 in 1994 to 1995, D10 and D11 in 2000. It indicates that epidemic outbreaks of AdV-37 coincided with the new genome type emerged.

Keywords: adenovirus • conjunctivitis • clinical (human) or epidemiologic studies: bio