Aromatic compound-dependent Staphylococcus aureus is safety in a nasal colonization leukopenic murine model

BARBAGELATA M; ALVAREZ L; DOTTO C; LATTAR S; SORDELLI D; BUZZOLA F

International Journal of Microbiology

Hindawi Publishing Corporation

Año: 2012 p. 1 - 7

1687-918X

Staphylococcus aureus nasal carriage is a risk factor for individuals suffering 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 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 contruct a safety ΔaroA mutant of S. aureus and to discriminate its from nasal colonizing and osteomyelitis S. aureus isolates by SmaI pulsed-field gel electrophoresis (PFGE) typing. The ΔaroA mutant, named RD17, exhibited an LD50 (3.2x106 CFU) significant higher than that of the parental strain (2.2x103 CFU). The colonies number of RD17 mutant recovered from nares of leukopenic mice was similar than that observed in the animals of the control group. Therefore, the aroA mutant demonstrated be safety due to maintain low growth levels in the nares regardless of immune status of the animals. The PFGE typing allowed the unequivocal identification of the S. aureus aroA mutants from S. aureus nasal colonizing and osteomyelitis isolates. This information could be important to discriminate endogenous infections from laboratory strains of S. aureus.