Journal of Research in Medical Sciences1735-1995220201705091066210662ENInfectious Diseases and Tropical Medicine Research Center Shahid Beheshti University of Medical Sciences Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Velenjak Koodakyar Ave., Tehran, IranInfectious Diseases and Tropical Medicine Research Center Shahid Beheshti University of Medical Sciences Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Velenjak Koodakyar Ave., Tehran, IranInfectious Diseases and Tropical Medicine Research Center Shahid Beheshti University of Medical Sciences Infectious Diseases and Tropical Medicine Research Center, Shahid Beheshti University of Medical Sciences, Velenjak Koodakyar Ave., Tehran, Iran20170506<p><span class="fontstyle0">Background: </span><span class="fontstyle2">Tis study was aimed to determine frequency and antimicrobial susceptibility of Community-acquired methicillin-resistant </span><span class="fontstyle3">Staphylococcus aureus </span><span class="fontstyle2">(CA-MRSA) among colonized patients in outpatient status. </span><span class="fontstyle0">Materials and Methods: </span><span class="fontstyle2">A total of 2000 nasal nares specimens were collected and inoculated on mannitol salt agar. MRSAs were identified based on mannitol positivity and coagulase test followed by cefoxitin disc diffusion test. Antimicrobial susceptibility of MRSA isolates was performed by E-test method for vancomycin and doxycycline as well as disc diffusion method for sulfamethoxazole-trimethoprim (SMX-TMP), erythromycin, linezolid, and clindamycin. D-test was performed for detection of inducible resistance to clindamycin. </span><span class="fontstyle0">Results: </span><span class="fontstyle2">Overall, nasal carrier rate of </span><span class="fontstyle3">S. aureus </span><span class="fontstyle2">and CA-MRSA was estimated 22% and 1.25%, respectively. Out of the 440 </span><span class="fontstyle3">S</span><span class="fontstyle2">. </span><span class="fontstyle3">aureus </span><span class="fontstyle2">isolates, 25 isolates were MRSA. All were susceptible to vancomycin and linezolid, and susceptibility rates to SMX-TMP, erythromycin,  levofloxacin, doxycycline, and clindamycin were 68%, 44%, 48%, 40% and 44%, respectively; furthermore, 28.5% of resistant isolates to erythromycin had inducible resistance to clindamycin. </span><span class="fontstyle0" style="color: #ed028c;">Conclusion</span><span class="fontstyle0">: </span><span class="fontstyle2">It seems susceptibility to clindamycin and SMX-TMP, recommended agents for empirical treatment of suspected CA-MRSA, are not promising.Vancomycin and linezolid are effective and reliable antibiotics for the treatment of </span><span class="fontstyle3">S</span><span class="fontstyle2">. </span><span class="fontstyle3">aureus </span><span class="fontstyle2">infections.</span></p><p><span class="fontstyle2">Key words: Antimicrobial susceptibility, Community-acquired methicillin-resistant Staphylococcus aureus, nasal carrier</span></p>http://jrms.mui.ac.ir/index.php/jrms/article/view/10662http://jrms.mui.ac.ir/index.php/jrms/article/download/10662/5492