en ميکروب شناسي Microbiology Research Article Research Article <div style="text-align: justify;"><span style="font-size:12px;"><span style="font-family:Times New Roman;"><span style="line-height:200%"><span style="unicode-bidi:embed"><span calibri=""><b><span style="line-height:200%"><span new="" roman="" times="">Background</span></span></b><span style="line-height:200%"><span new="" roman="" times="">: <span style="color:black">Fluoroquinolones are a class of broad-spectrum antimicrobials typically used for the treatment of lower </span>urinary tract infections<span style="color:black">. </span>We aimed to determine the frequency of quinolone resistance genes in <i>Klebsiella pneumoniae</i> isolates from urinary tract infections in Guilan Province, Iran.</span></span></span></span></span><br> <span style="line-height:200%"><span style="unicode-bidi:embed"><span calibri=""><b><span style="line-height:200%"><span new="" roman="" times="">Methods: </span></span></b><span style="line-height:200%"><span new="" roman="" times="">The resistance of 114 clinical isolates of <i>K. pneumoniae</i> to common <span style="color:black">fluoroquinolones</span> and the minimum inhibitory concentration of ciprofloxacin were determined by disk diffusion and broth microdilution methods, respectively. Frequency of five plasmid-mediated quinolone resistance (PMQR) genes including<i> qnrA</i>, <i>qnrB</i>, <i>qnrS</i>, </span></span><i><span style="line-height:200%"><span new="" roman="" times="">qepA</span></span></i><span style="line-height:200%"><span new="" roman="" times="">, and <i>aac (6&#39;)-Ib-cr</i> was determined by PCR.&nbsp;</span></span></span></span></span><br> <span style="line-height:200%"><span style="unicode-bidi:embed"><span calibri=""><b><span style="line-height:200%"><span new="" roman="" times="">Results.</span></span></b><span style="line-height:200%"><span new="" roman="" times=""> According to phenotypic assays, 60 isolates (52.6%) were resistant to at least one quinolone compound, 42 isolates (36.8%) were resistant to all tested quinolones, and 28 isolates (24.6%) showed a high level of ciprofloxacin resistance. In addition, </span></span><i><span style="line-height:200%"><span new="" roman="" times="">aac(6&#39;)-Ib-cr </span></span></i><span style="line-height:200%"><span new="" roman="" times="">was the most common PMQR gene (</span><span cambria="" math="">𝑛</span><span new="" roman="" times=""> = 44), followed by <i>qnrS </i>(</span><span cambria="" math="">𝑛</span><span new="" roman="" times=""> = 32), and <i>qnrB </i>(</span><span cambria="" math="">𝑛</span><span new="" roman="" times=""> = 21). </span></span><span style="line-height:200%"><span style="font-family:"Times New Roman",serif"></span></span></span></span></span><br> <span style="line-height:200%"><span style="unicode-bidi:embed"><span calibri=""><b><span style="line-height:200%"><span new="" roman="" times="">Conclusion: </span></span></b><span style="line-height:200%"><span new="" roman="" times="">The possible dissemination of PMQR genes poses a serious threat to the management of infections by resistant <i>Klebsiella pneumoniae</i>. </span></span></span></span></span></span></span></div> Plasmids,quinolone,Klebsiella pneumoniae, 32 37 http://mlj.goums.ac.ir/browse.php?a_code=A-10-1216-1&slc_lang=en&sid=1 Leila Asadpour l.asadpour@yahoo.com 100319475328460032004 100319475328460032004 Yes Department of Biology, Rasht Branch, Islamic Azad University, Rasht, Iran Mohammad Moradi Bazghaleh m.moradi.vet@gmail.com 100319475328460032005 100319475328460032005 No PhD Student of Bacteriology, Department of Pathobiology, Faculty of Specialized Veterinary Sciences, Science and Research Branch, Islamic Azad University, Tehran, Iran