The significance of nasal carriage of Staphylococcus aureus as risk factorfor human skin infections

The present study was designed to investigate the significance and the rela tionship between nasal carriage of Staphylococcus aureus and staphylococcal skin infections. Thirty-one S. aureus strains, isolated from 12 patients w ith chronic and recurrent skin infections, one patient with septicemia and one patient with otitis externa were studied. The staphylococcal strains we re isolated from the site of infection and from the anterior nares of each patient. The identity of both strains of each pair could be demonstrated by determination of phenotypic properties and by genotyping of the isolates. The phenotypic properties included hemolytic activities, antibiotic resista nce data, and the production of enterotoxins. The identity was additionally confirmed by phage-typing, by determination of the size and the number of repeats of the X region of spa gene, by determination of gene polymorphisms of coa gene and by macro restriction analysis of the chromosomal DNA of th e isolates by pulsed-field gel electrophoresis. The present results showed an identity of the S. aureus obtained from anterior nares and from skin inf ection of each patient indicating the importance of nasal carriage of these bacteria for development of human skin infection. (C) 2001 Federation of E uropean Microbiological Societies. Published by Elsevier Science B.V. All r ights reserved.