Genetic characterization of adenovirus strains isolated from patients with acute conjunctivitis in the city of S�o Paulo, Brazil

Abstract

Genome analysis was carried out on adenovirus strains isolated from patients with acute follicular conjunctivitis in the city of São Paulo, Brazil. Eighteen conjunctival scrapings, collected between December 1993 and March 1994, were analyzed by two methods: a combination of polymerase chain reaction with restriction fragment length polymorphism and viral DNA restriction analysis, carried out using 10 restriction endonucleases: BamHI, BglI, BglII, HindIII, KpnI, SacI, SalI, SmaI, XbaI, and XhoI. Among 11 adenovirus detected by cell culture isolation, nine were Ad8, and two were Ad7. By restriction analysis the Ad8 isolates were typed as two new variants-Ad8/D11 (seven of nine samples) and Ad8/D12 (two of nine samples). Ad7 isolates were identified as a subtype of the widespread genome type Ad7b and the virulent type Ad7h, a predominant genome type circulating in Argentina, Chile, and Uruguay but absent in Brazil until 1991.

Human adenovirus type 8 genome typing

“…Adrian et al (1990) used six RE patterns in alphabetical order (BamHI, BglII, HindIII, KpnI, SalI and SmaI). Later, BglI, BstEII and SacI were included in successive studies (de Jong et al, 1992;Tanaka et al, 2000). The cleavage pattern of the prototypes for all REs was labelled as enzyme code 1.…”

“…HAdV-8/D1 is, by definition, the DNA variant to which prototype strain Trim belongs. So far, HAdV-8/D1-HAdV-8/D12 have been described (Table 2) (Adrian et al, 1990;de Jong et al, 1992;Tanaka et al, 2000). In this classification system, BglI and HindIII are the most discriminating enzymes, followed by BamHI, BglII and SalI.…”

“…A genome typing study was carried out in Brest, France, where four consecutive outbreaks of HAdV-8 EKC occurred over a 5-year period (1983)(1984)(1985)(1986)(1987)(1988) (Tanaka et al, 2000).…”

“…This method enables prediction of a possible correlation between genomic variation and virulence of the strain. So far, HAdV-8A-8K and HAdV-8/ D1-D12 have been described using the Asian and European classification systems of genome typing, respectively (Fujii et al, 1983Fujii & Yamashita, 1984;Ishii et al, 1987;Sawada et al, 1987;Sheu et al, 1987;Guo et al, 1988;Chang et al, 2001;Adhikary et al, 2003Adhikary et al, , 2011Ohguchi et al, 2003;Jin et al, 2011;Takács et al, 1983;Adrian et al, 1990;de Jong et al, 1992;Tanaka et al, 2000). Nevertheless, there have also been several problems with genome typing, such as the application of variable numbers and types of REs as well as difficulties in the interpretation of results due to the lack of a published catalogue of HAdV-8 genome types.…”

A naturally occurring human adenovirus type 7 variant with a 1743 bp deletion in the E3 cassette

“…The 7b genome type became the predominant type of HAdV-7 circulating throughout Brazil from the early 1980s through to the mid-1990s. It was detected in São Paulo city and Rio de Janeiro (Gomes et al, 1989;Hársi et al, 1995;Kajon et al, 1999;Moraes et al, 1997) and it was itself replaced, in 1995, by HAdV7h, as documented from respiratory samples collected in São Paulo city (Moura et al, 2007a;Tanaka et al, 2000;). Interestingly, neither HAdV-7b nor -7h were identified in our study.…”