Staphylococcus aureus is a major human pathogen, causing both hospital and community-acquired infections. It is responsible for 25% of healthcare-associated infections and contributes substantially to morbidity and cost of hospital stays. The source of many of these infections is thought to be the patients’ endogenous flora. The ecological niche of S. aureus is the anterior nostrils, and 25e30% of individuals are colonized at a given time. Numerous studies have linked nasal carriage of S. aureus with increased risk of infection with S. aureus in various settings. A study conducted in central Italy to establish the rates of nasal carriage of S. aureus and antibiotic susceptibility patterns in the community showed that the prevalence of nasal carriage of S. aureus was 30 5%, with only one subject identified as a carrier of meticillin-resistant S. aureus (MRSA) (prevalence 0 12%). In another Italian study conducted in injection drug users, the prevalence of nasal colonization with S. aureus was 8.83%, and 12.5% of isolates were found to be meticillin resistant. Recently, concern has increased regarding the spread of MRSA in the community and schools. Students with weakened immune systemsmay be at risk formore severe illness if