Nasal carriage and antimicrobial susceptibility of Staphylococcus aureus among medical students at the HRH Princess Maha Chakri Sirindhorn Medical Center, Thailand: A cross sectional study

Abstract

Objective: To determine the epidemiology of the nasal carriage of Staphylococcus aureus and its susceptibility pattern among preclinical medical students at the HRH Princess Maha Chakri Sirindhorn Medical Center, Srinakharinwirot University. Methods: Nasal swabs were taken from 128 preclinical medical students prior to working at the hospital. Susceptibility testing of S. aureus was performed using Kirby Bauer's disc diffusion method. Results: Of the 128 participants, 38/128 (29.7%; 95% confidence interval [CI]. =. 21.8%, 37.6%) were carriers of S. aureus. No methicillin-resistant S. aureus was detected by the cefoxitin disk diffusion test. Resistance of S. aureus to erythromycin, clindamycin, tetracycline, chloramphenicol and fusidic acid was observed at the following rates: 63.2% (95% CI; 47.8%, 78.5%), 63.2% (95% CI; 47.8%, 78.5%), 34.2% (95% CI; 19.1%, 49.3%), 2.6% (95% CI; -2.5%, 7.7%) and 2.6% (95% CI; -2.5%, 7.7%), respectively. There was no statistically significant correlation between nasal carriage of S. aureus and possible risk factors. Conclusions: The prevalence of asymptomatic nasal carriage of S. aureus was higher than reported by previous literature in Thailand, and S. aureus isolates exhibited relatively high resistance to erythromycin and clindamycin. © 2013 King Saud Bin Abdulaziz University for Health Sciences.