Prevalence and Antibiotic Resistance Profile of Staphylococcus aureus Nasal Carriage among a School Community

Nasal carriage of Staphylococcus aureus plays a key role in the transmission of this opportunistic pathogen within communities and in the development of endogenous infections. This study aimed to determine the prevalence of nasal carriage of S. aureus and to assess the antibiotic resistance profile of isolates among school students in Sri Lanka. Nasal swabs were collected from 50 students and cultured on Baird–Parker medium. Identification was performed using colony morphology, Gram staining, and standard biochemical tests. Antibiotic susceptibility testing was carried out using the disc diffusion method in accordance with Clinical and Laboratory Standards Institute guidelines. S. aureus was isolated from 35 students, indicating a prevalence of 70%. All isolates were sensitive to vancomycin, streptomycin, ciprofloxacin, erythromycin, and clindamycin, while all isolates were resistant to ampicillin. Resistance to penicillin was observed in 45.7% of isolates. This study provides one of the few reports on S. aureus nasal carriage among school-aged adolescents in Sri Lanka and demonstrates a high prevalence with notable resistance to β-lactam antibiotics, highlighting the need for continuous community-level surveillance and prudent antimicrobial use.