Characterization of adenovirus 15/H9 intermediate strains

17 adenovirus strains from various parts of the United States and Europe were characterized by immunological and biochemical methods. They were antigenically related to adenovirus 15 (Ad15) in neutralization tests. In hemagglutination-inhibition tests, a relationship was seen to Ad9, but not to Ad15. These strains were named Ad15/H9 intermediate strains. The relatedness of prototypes Ad15 and Ad29 in neutralization tests and of Ad9 and Ad8 in hemagglutination-inhibition tests was also found in the strains studied. The DNAs of these strains were analyzed by use of restriction endonucleases. After cleavage with the enzymes BamHI, BglII, BstEII, HindIII, and SmaI, fragment patterns of Ad15/H9 strains were found to be different from the prototypes and were more closely related to Ad9 than to Ad15. Furthermore, the 17 strains could be classified into six different genome types, a-f.