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International Journal of Microbiology
Volume 2012, Article ID 468539, 7 pages
Research Article

Aromatic Compound-Dependent Staphylococcus aureus Is Safe in a Nasal Colonization Leukopenic Murine Model

1Departamento de Microbiología, Parasitología e Inmunología, Facultad de Medicina, Universidad de Buenos Aires, C1121ABG Buenos Aires, Argentina
2Instituto de Microbiología y Parasitología Médica, Facultad de Medicina, Universidad de Buenos Aires-Consejo Nacional de Investigaciones Científicas y Tecnológicas (IMPaM, UBA-CONICET), Paraguay 2155, Piso 12, C1121ABG Buenos Aires, Argentina

Received 20 March 2012; Revised 28 June 2012; Accepted 28 June 2012

Academic Editor: Todd R. Callaway

Copyright © 2012 María 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. aureus mutant 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 identification of the S. aureus and differentiation of aroA mutants in nasal colonizing and osteomyelitis isolates. This information could be important to discriminate endogenous infections from laboratory strains of S. aureus.