RANDOM AMPLIFIED POLYMORPHIC DNA TYPING VERSUS PULSED-FIELD GEL-ELECTROPHORESIS FOR EPIDEMIOLOGIC TYPING OF VANCOMYCIN-RESISTANT ENTEROCOCCI

Sixty vancomycin-resistant vanA mutant Enterococcus faecium (VRE) isol ates, collected during a 40-month period from 48 patients hospitalized in a French Cancer Referral Center, were typed by using random amplif ied polymorphic DNA (RAPD), and the results were compared with those p reviously obtained by typing with SmaI pulsed-field gel electrophoresi s (PFGE), which is currently recognized as the ''gold standard.'' The discriminating power of RAPD typing, with seven primers and 11 combina tions of primers, was tested on 18 strains, and only the most discrimi nating combination was further tested on the whole collection. We comp ared the epidemiological usefulness of RAPD typing of 60 clinical VRE isolates with that of SmaI PFGE typing. With primers AP4 and ERIC1R, R APD generated 30 patterns versus the 36 patterns generated by SmaI PFG E. However, this did not hamper the epidemiologically correct clusteri ng of 15 related strains and the detection of multiple colonization in nine patients. We conclude that this simple RAPD technique is well su ited to the epidemiological typing of VRE and the monitoring of its no socomial spread.