The Journal of Medical Microbiology, Vol 33, Issue 2 91-96, Copyright © 1990 by Society for General Microbiology
Application of small fragment restriction endonuclease analysis (SF-REA) to the epidemiological fingerprinting of Staphylococcus aureus
R. Haertl and G. Bandlow
Staatliches Medizinaluntersuchungsamt Osnabrueck, Federal Republic of Germany.
Total cell DNA of 14 isolates of Staphylococcus aureus from patients of an
intensive care unit (ICU) and 180 unrelated strains was examined by
restriction endonuclease analysis (REA). EcoRI-generated DNA fragments were
either subjected to conventional REA on agarose gels and stained with
ethidium bromide or separated by polyacrylamide gel electrophoresis and
visualised by silver staining (SF-REA). Both methods were compared for
inter-strain discriminatory ability, reproducibility and handling. All
DNA-cleavage patterns of unrelated strains clearly differed from each other
when subjected to SF-REA. In contrast, all S. aureus isolates from the ICU
gave identical restriction fragment patterns. These findings supported the
suspicion of nosocomial infection in these patients. Conventional REA
proved the identity of the ICU isolates, but it failed to differentiate
between some of the unrelated strains. Therefore SF-REA of total cell DNA
seemed to be superior. It has proved to be a very useful technique for
studying the epidemiology of S. aureus in hospitals.
