en میکروب شناسی Microbiology مقالات اصلی Original Article <div style="text-align: justify;"><strong>Background: </strong><em>Mycoplasma pneumoniae</em> is one of the widespread causes of community-acquired pneumonia (CAP). Over recent years, the widespread use of macrolides has led to the emergence of macrolide-resistant <em>M. pneumoniae</em>&nbsp;(MRMP) resulted from mutations at specific positions of domain V of the <em>23S rRNA</em> gene.<br> &nbsp;</div> <div style="text-align: justify;"><strong>Methods:</strong> We collected 100 samples of throat swabs from patients with respiratory infections. After extraction of DNA from bacterial cell cultured in PPLO broth media using Roche kit (Germany), the PCR was performed on specific samples of <em>M. pneumoniae</em> using specific primers for <em>23S rRNA</em> gene. Afterwards, for positive samples, minimum inhibitory concentration (MIC) was determined using the broth microdilution with Clarithromycin. Finally, the PCR product was sequenced to detect mutations related to macrolide resistance in domain V of <em>23S rRNA</em>.<br> &nbsp;</div> <div style="text-align: justify;"><strong>Results:</strong> According to the analysis of the sequenced PCR product of <em>M. pneumoniae</em> <em>23S rRNA</em> gene using Clustalw2 online software, one of the samples were shown to have a mutation at A2431G and G2491A positions. The MIC measurement also revealed that all isolates were sensitive to Clarithromycin, and there was no macrolide resistance to Clarithromycin in all isolates.<br> &nbsp;</div> <div style="text-align: justify;"><strong>Conclusion: </strong>Sequence analysis of the <em>23S rRNA</em> gene in <em>M. pneumoniae</em>, revealed no macrolide resistance of <em>M. pneumoniae </em>to Clarithromycin. Thus, the use of these antibiotics should be restricted to prevent the development of macrolide-resistant <em>M.&nbsp;pneumoniae</em> in Iran.</div> Clarithromycin, Macrolide resistance, Mycoplasma pneumonia, 23S rRNA gene 156 162 http://rbmb.net/browse.php?a_code=A-10-373-2&slc_lang=en&sid=1 Hanieh Beikmohammadi 100319475328460017574 100319475328460017574 No Department of Microbiology, Islamic Azad University, Qom Branch, Iran Iman Pouladi 100319475328460017575 100319475328460017575 No Department of Microbiology, Faculty of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran Mohammad Reza Zolfaghari 100319475328460017576 100319475328460017576 No Department of Microbiology, Islamic Azad University, Qom Branch, Iran Mohammad Niakan niakan@shahed.ac.ir 100319475328460017577 100319475328460017577 Yes Department of Medical Microbiology, Faculty of Medicine, Shahed University, Tehran, Iran