fa بررسی ارتباط بین ژن‌های القایی عامل کروم سنسینگ وابسته به پروموتور و مقاومت به متی سیلین در سویه‌های استافیلوکوک اورئوس بالینی کارآزمایی بالینی Clinical Trials <p style="text-align: justify;"><span style="font-size:16px;"><span style="font-family:Times New Roman;"><strong><em><span style="color:#008080;">Background and Objective:</span> </em></strong>Quorum sensing (QS) phenomenon, promoters involved in this pathway and the effect of these promoters on the expression of some structural genes, such as <em>agrA</em> and <em>PII</em>, could reveal the proper activity and gene expression of antibiotic resistance in <em>S. aureus</em>. The aim of this study was defining the relationship between promoter-dependent Quorum Sensing induced genes and methicillin resistance in clinical strains of <em>S. aureus</em>.<br> <span style="color:#008080;"><strong><em>Materials and Methods:</em></strong></span> In this analytical study, 315 isolates of <em>S.</em> <em>aureus</em> were collected. Resistant and susceptible strains were evaluated for the presence of promoter-dependent quorum sensing induced genes qualitatively and quantitatively. Calculating the gene expression of <em>agrA</em> and <em>PII</em> was carried out by Real-Time PCR. Statistical analysis (descriptive and analytical) was done using SPSS version 16 software and the data analysis of gene expression was carried out by REST 2008 V3.<br> <span style="color:#008080;"><strong><em>Results:</em></strong></span> Among 125 strains of <em>S. aureus</em> resistant to methicillin, 100 isolates (83/33%) had the promoter <em>P2</em> gene and all isolates had the <em>agrA</em> gene and of 190 strains susceptible to methicillin, 84 isolates (44/21%) had the <em>P2</em> gene and 169 isolated (88/94%) had the <em>agrA</em> gene. <em>P2</em> and <em>AgrA</em> gene expression was greater in the resistant isolates in comparison to susceptible isolates.<br> <span style="color:#008080;"><strong><em>Conclusion:</em></strong></span> In accordance with the results of this study, the association between quorum sensing /gene induction and drug resistance is a matter of importance.</span></span></p> Keywords: Quorum sensing, Drug resistance, Staphylococcus aureus, Gene expression 75 87 http://journal.zums.ac.ir/browse.php?a_code=A-10-4-1084&slc_lang=fa&sid=1 Sanaz Dehbashi ساناز ده باشی 5200319475328460051003 5200319475328460051003 Yes Dept. of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran دانشگاه علوم پزشکی همدان، همدان Hamed Tahmasebi حامد طهماسبی 5200319475328460051004 5200319475328460051004 No Dept. of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran دانشگاه علوم پزشکی همدان، همدان Behrouz Zeyni بهروز زینی 5200319475328460051005 5200319475328460051005 No Dept. of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran دانشگاه علوم پزشکی همدان، همدان Mohammad Reza Arabestani محمدرضا عربستانی mohammad.arabestani@gmail.com 5200319475328460051006 5200319475328460051006 No Dept. of Microbiology, Faculty of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran دانشگاه علوم پزشکی همدان، همدان