Restriction endonuclease analysis of RAPD-PCR amplicons derived from Shiga-like toxin-producing Escherichia coli O157 isolates

Shiga-like toxin-producing Escherichia coli O157 isolates were characterise d by random amplification of polymorphic DNA by PCR (RAPD-PCR) analysis dev eloped to allow robust epidemiological typing of E. coli. Amplification wit h primer 1247 or 1290 generated a reproducible profile, but was not capable of distinguishing sufficiently between epidemiologically unrelated strains . Subsequent digestion of the amplicons with selected restriction endonucle ases improved the discriminatory ability of this method for strains showing limited differentiation following RAPD-PCR analysis alone. Restriction end onuclease analysis of RAPD-PCR fragments generated from closely related str ains has the potential to provide additional discriminatory information wit hout loss of specificity.