The frequency and antibiotic susceptibility of staphylococcus aureus from nasal swabs in an suburban marginal population in Lima, Peru

Objectives. To determine the frequency and associated factors of nasal colonization by Staphylococcus aureus and its antibiotic susceptibility pattern in a marginal suburban population Lima, Peru. Materials and methods. A cross-sectional study was conducted among population of all ages from a marginal suburban district in northern Lima. The study used a convenience sample. Each person was surveyed and provided a swab sample of the nostrils. The swab samples were analyzed to identify Staphylococcus aureus, determining the susceptibility pattern by the Kirby Bauer disk diffusion method. Results. From the 452 participants recruited, ages between 1 and 84 years, the frequency of Staphylococcus aureus nasal colonization was 24.6%, with 0.9% of them resistant to methicillin. The only factor associated with nasal colonization was age equal or less than 11 years (OR: 3.80, 95% CI 1.42 to 10.16). Most strains were resistant to penicillin (96.4%) but also to erythromycin (10.9%), clindamycin (7.3%) and gentamicin (4.5%). Conclusions. The frequency of Staphylococcus aureus nasal colonization was similar to other studies worldwide, with predominance of methicillin-sensitive strains.