Comparative study of five different techniques for epidemiological typing of Escherichia coli O157

A set of 47 Austrian human, food, and veterinary Escherichia coli O157:H7 i solated was used to evaluate five different epidemiological typing methods. Ribotyping using ni? automated microbial characterization system (RiboPrin ter(TM)) was not suitable for detection of epidemiological relatedness. All brit one E. coli strain were typeable by phage typing Random amplified pol ymorphic DNA-PCR fingerprinting was performed using primer M13 containing t he sequence 5'-GAG GGT GGC GGT TCT-3' and primer 1247 (5'-AAGAGCCCGT-3'). A lthough both methods recognized only two clusters, both dendrograms grouped most of the EHEC O157 isolates into epidemiologically related subgroups. P ulsed-field gel electrophoresis of XbaI digested total DNA was a valuable s ubtyping system. We found that major differences can exist between results of multiple subtyping methods. E. coli O157 isolates should not be classifi ed as epidemiologically! related oi nonrelated on the basis of a single typ ing method alone. (C) 1998 Elsevier Science Inc.