Frequency of Nasal Carriage of Staphylococcus aureus and Its Antimicrobial Resistance in Hamadan's Medical Students

Introduction &

Staphylococcus aureus has been known as one of the most common nosocomial pathogens worldwide. Methicillin-resistant S. aureus is one of the most important nosocomial pathogens with increasing global prevalence in the recent 3 decades. The aim of this study was to assess the prevalence of nasal carriage of this organism in medical students because they، being potential carriers، can be considered as one of the infection sources.

In a cross-sectional study nasal swabs were collected from 258 medical students (103 males and 155 females) including: 116 preclinical، 92 clinical students and 50 residents. Samples were cultured on blood agar. S. aureus isolates were further analyzed for antibiotic resistance with agar disk diffusion method. Each person was questioned for sex، grade، recent disease and drug history and family members’ employment in hospital.

25. 2% of 258 students were positive for nasal carriage of S. aureus. There was no significant difference among sexes or grades in carrier prevalence. Most isolates were resistant to penicillin (92. 3%)، and 47. 7% were methicillin-resistant. Most methicillin-resistant strains were isolated from clinical students (87%)، and most vancomycine-resistant isolates were found in residents (30. 8%).

The rate of nasal carriage of S. aureus in medical students was similar to general population and hospital personnel but the rate of MRSA and vancomycin-resistant S. aureus carriers in the students is more than hospital personnel.