During an epidemiological survey of acute respiratory infection in Rio
de Janeiro, among 208 adenovirus isolates, we found two strains that we
were not able, by a standard neutralization procedure, to distinguish
between type 3 or 7. However, DNA restriction pattern for the two strains
with different enzymes were analyzed and showed a typical Ad3h profile.
Using a cross-neutralization test in which both Ad3p and Ad7p antisera were
used in different concentration against 100 TCID50 of each adenovirus
standard and both isolates, we were able to confirm that the two isolates
belong to serotype 3. An hemagglutination inhibition test also corroborated
the identification of both strains as adenovirus type 3. Comparing Ad3h and
Ad3p genome, we observed 16 different restriction enzyme sites, three of
which were located in genomic regions encoding polypeptides involved in
neutralization.
