A method for DNA restriction endonuclease fingerprinting of coagulase-negative staphylococci

Abstract

A method was developed for restriction endonuclease fingerprinting (REF) of chromosomal DNA of coagulase-negative staphylococci. A total of 25 reference strains representing 15 coagulase-negative staphylococcus species from the American Type Culture Collection were examined. Plasmid profile analysis, antimicrobial susceptibility testing and biotyping were also employed for characterization of these strains. Amongst 14 restriction endonucleases examined in this study, ClaI produced the most discriminatory REF patterns; those patterns consisted of up to 100 bands in a molecular size range of 1–33 kilobase pairs. On the basis of numerical analysis of REf patterns, the 25 reference strains were classified into 15 species specific groups. REF typing distinguished individual subspecies groups with various degrees of genetic similarities. Intraspecies similarily values ranged from 60 to 91%; interspecies similarity values did not exceed 50.2%. REF proved to be a specific and reproducible typing method which could be applicable to molecular epidemiology of genetically diverse group of coagulase-negative staphylococci.