Prevalence of Staphylococcus aureus and MRSA among Medical and Medical Laboratory students of Shahid Sadoughi of Medical Sciences, Yazd, Iran

Introduction and Objectives: Staphylococcus aureus is a major pathogen within hospital and in the community. This bacterium colonizes the skin and in the anterior nose of about 25-30%of healthy people. During the past four decades, methicillin- resistant staphylococcus aureus (MRSA) has spread in hospital and community worldwide. The spread of MRSA indicates that preventive strategies in world societies are inadequate implemented. Determination of nasal carriage frequency and antibiotic resistance of S. aureus isolated from medical and paramedical students of Shahid Sadoughi University of Medical Sciences was the major aim of the present study. Materials and Methods: Following completing a questioner sheet for 177 students, a nasal swab was collected and inoculated on MSA and after 24 hours incubation; suspected colonies were further applied for gram stain, catalase and coagulase tests. The isolated S. aureus was then proceeding for antibiogram with Disk Diffusion Method using: penicillin, gentamycin, erythromycin, rifampin, ciprofloxacin, tetracycline, clindamycin, trimethoprim- sulfamethoxazole, cefoxitin, chloramphenicol, nitrofurantoin. Inducible clindamycin resistance was identified using D-zone test. Results: Among 177 students, 100 were Medical and the remaining 77 were Medical Lab students. Overall, 38 cases (21.5%) were nasal colonized of S, aureus; in which 28 (73.7%) were medical and 10 (26.3%) Medical Lab students. The most sensitive antibiotic were found to be nitrofurantoin and rifampin (100%) and the resistance antibiotic was penicillin (100%). note that (2.64%) of isolated S. aureus was resistance (MRSA) and the remaining were sensitive to cefoxitin (97.36%). D test was positive in 7.9% of cases. Conclusion: Although isolation of MRSA in this survey was limited, high frequency of S. aureus carriage among medical students is highly considerable.

Keywords:

MRSA , antibiotic resistance , Medical students , Medical Lab students , Staphylococcus. aureus , carrier