doi:10.1155/2012/468539 Research Article Aromatic Compound-Dependent Staphylococcus aureus Is Safe in a Nasal Colonization Leukopenic MurineModel

Copyright © 2012 Marı́a S. Barbagelata et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Staphylococcus aureus nasal carriage is a risk factor for individuals suffering from trauma, surgical procedures, invasive devices, and/ or decreased immunity. Recently, we demonstrated that artificial nasal colonization with an attenuated S. aureusmutant reduced by bacterial interference with the colonization of pathogenic strains of S. aureus. This could be an optional tool to diminish the rate of S. aureus infections in hospitalized patients. The aim of this study was to construct a safe ΔaroA mutant of S. aureus and to discriminate it from nasal colonizing and osteomyelitis S. aureus isolates by SmaI pulsed-field gel electrophoresis (PFGE) typing. The ΔaroA mutant, named RD17, exhibited an LD50 (3.2 × 106 colony-forming unit (CFU)) significantly higher than that of the parental strain (2.2 × 103 CFU). The colony number of the RD17 mutants recovered from nares of leukopenic mice was similar to that observed in the animals of the control group. Therefore, the ΔaroA mutant was demonstrated to be safe due to maintaining low growth levels in the nares regardless of immune status of the animals. PFGE typing allowed the unequivocal identificatio