Nasal Carriage and Resistance Pattern of Staphylococcus aureus Among Healthy Medical Students

Background: Staphylococcus aureus nasal carriage plays an important role in the epidemiology and pathogenesis of infections, and this status accounts for both community-acquired and nosocomial infections. Objectives: This study was conducted to determine the frequency of the nasal carriage of S. aureus in healthy medical students. Patients and Methods: This cross-sectional study was undertaken among medical students from August of 2012 until January of 2013. Nasal samples from both anterior nares were obtained from the subjects using sterile moistened swabs, and the isolates were identified as S. aureus by the standard microbiological tests. The antibiotic susceptibility profiles were determined by the disc diffusion method according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Results: Out of the 200 nasal swabs obtained, the overall nasal carriage of S. aureus was 24.5% (49/200). The prevalences of the methicillin-susceptible and resistant Staphylococcus aureus nasal carriage were 20% (40/200) and 4.5% (9/200), respectively, while the antibiotic susceptibility tests revealed that all 49 S. aureus isolates were sensitive to mupirocin. Conclusions: Despite the higher frequency of S. aureus nasal carriage in the interns, compared to the first year students, the difference did not reach statistical significance. Therefore, attendance at medical centers cannot be considered a risk factor for increasing carriage.