Bacterial molecular epidemiology based on a nonradioactive probe complementary to ribosomal RNA.

The use of plasmid pKK3535 (a pBR322-derived plasmid containing a ribosomal RNA operon) is described for determining rRNA gene restriction patterns. The plasmid allowed the use of both radioactive as well as nonradioactive procedures and provided features that are necessary for the inclusion of internal and/or external standards that facilitate comparison of strains. The patterns generated are identical to those obtained by hybridization with 32P-labelled rRNA.