Genomic heterogeneities in bovine herpesvirus type 1 viral isolates: a major variant selected from a field isolate.

We have analyzed viral DNA patterns, obtained following digestion of six different infectious bovine rhinotracheitis isolates, using a panel of restriction enzymes. Several differences in profiles were observed, particularly for a Canadian viral strain which presumably contained a genome that was larger than the other five infectious bovine rhinotracheitis genomes. Also, an insertion/deletion of a HindIII restriction site was found in the DNA of a Danish strain; this additional HindIII site was localized precisely within the original HindIII E fragment of the infectious bovine rhinotracheitis virus. Interestingly, results could be used to distinguish each viral strain examined from the others by simple digestion with the appropriate enzyme.