Prevalence Methıcıllın-Resıstant Staphylococcus aureus (MRSA) Nasal Carrıage among Healthy Students of Medıcal Schools in Istanbul (Turkey)

Nasal carriage of MRSA plays a key role in the epidemiology and pathogenesis of staphylococcal infections. The aim of this study is to examine nasal MRSA carriage among healthy pre-clinical and clinical medical students at School of Medicine in Istanbul (Turkey). We also evaluate the antimicrobial resistance patterns of MRSA strains. In this study, involving 118 medical students, both pre-clinical (n:78) and clinical (n:40) at Bahçeşehir University, School of Medicine was conducted from October 2016 to June 2017. The volunteer students were screened for nasal carriage of S. aureus by streaking both anterior nares with sterile moistened cotton swabs. Then all nasal swabs and clinical specimens inoculated onto Chromagar MRSA and blood agar plate media and incubated at 35-37°C for 48 hours. The isolates were identified as S. aureus by standard coventional procedures. The antimicrobial susceptibility of the isolates was determined using by the Kirby-Bauer disk diffusion method, according to the EUCAST panels. MRSA carriage among pre-clinical and clinical students were 7.6 % (6/78) and 7.5% (3/40) respectively. There was no statistical significant different between the two groups. Also all MRSA strains isolated from pre-clinical medical students were susceptible to chloramphenicol and tigecycline, whereas numbers of susceptible strain to tetracycline, ciprofloxacin and erythromycin were 5, 4 and 3, respectively. All isolates from clinical medical students also found susceptible to ciprofloxacine, tigecycline and chloramphenicol, only two strains were susceptible to both tetracycline and erythromycin. In conclusion, under the light of these preliminary findings of the study, focused MRSA surveillance to medical students like other health care workers as a potential sources for that pathogen must be in a consideration. There is no statistical significance between both groups, in term of nasal carriage of MRSA and antimicrobial susceptibility patterns. Therefore , this trial would be continued with the same student groups till to their internship period which they will be fully practice in the hospital.