Typing of Staphylococcus epidermidis trains by random amplification of polymorphic DNA

The polymerase chain reaction was used to obtain randomly amplified polymorphic DNA profiles for typing of Sfup~ylococcus epiriermidis strains. Epidemiologic&y unrelated S. epidermidis isolates were screened with randomly amplified polymorphic DNA analysis. The discriminating ability of 45 randomly designed lo-mer primers was assessed. The highest discriminatory power was obtained with the lo-mer oligonucleotide OPAM-12. In typing a total of 13 unrelated S. epidermidh strains with OPAM-12, 11 different banding profiles were obtained reproducibly by agarose gel electrophoresis. The discriminatory power of the method with OPAM-12 was estimated using the D value of Huntet and Gaston (1988) to be 0.961. A reproducibility index of 1 was obtained after typing a total of 40 cultures including 12 triplicates and one quadruplicate of the 13 unrelated strains. Following the described procedure, the randomly amplified polymorphic DNA method provided a rapid, simple and reproducible alternative to other S. epidermidis typing systems