Genome analysis with restriction endonucleases recognizing 4- or 5-base pair sequences of adenovirus type.

PURPOSE To detect the genetic changes in adenovirus type 4 (Ad4) by DNA restriction endonuclease analysis during 1993-1995, when no epidemic outbreak of conjunctivitis occurred. METHODS We evaluated 16 Ad4 strains from patients with acute viral conjunctivitis at four eye clinics in Sapporo, northern Japan. Seven strains were obtained during the period from December 1993 through March 1994 (first period). Nine strains were obtained during the period from March through May 1995 (second period). These strains were analyzed using DNA restriction endonucleases, TaqI and HinfI. RESULTS The seven strains obtained during the first period showed identical DNA digestion patterns. The nine strains obtained during the second period showed two DNA digestion patterns using TaqI: five strains showed the same digestion pattern as that seen in the strains obtained during the first period, and four showed a different pattern. The genetic changes in Ad4 during 1993-1995 were less frequent than those reported previously during 1985-1989. CONCLUSION It is suggested that the decrease in the incidence of infection in 1993-1995 was related to the decrease in the incidence of mutation in the Ad4 DNA.