en باکتری شناسی پزشکی Medical Bacteriology مقاله پژوهشی Original Research Article <p style="text-align: justify;"><span style="font-size:16px;"><span style="font-family:Times New Roman;"><span style="color:#ffffff;"><b><span style="background:#1f497d"><span style="letter-spacing:-.1pt">Background and Aim:</span></span></b></span> <i>Listeria </i>(<i>L.</i>)<i> monocytogenes</i> is a foodborne pathogen found in various environments including water, soil, and food. Due to the high importance of this bacterium in public health and the potential differences between its lineages in pathogenicity, this study aimed to investigate and identify the phylogenetics of Listeria in food and environmental samples based on Listeriolysin O gene.<br> <span style="color:#ffffff;"><b><span style="background:#1f497d"><span style="letter-spacing:-.1pt">Materials and Methods:</span></span></b> </span>About 100 samples were collected from Shahriar and Andisheh counties, Iran in summer and fall. After the enrichment and cultivation on selective agar, the suspicious colonies were purified. Lineage identification was performed using mismatch amplification mutation assay-polymerase chain reaction (MAMA-PCR) specifically for Listeriolysin O gene. Data were analyzed using GraphPad Prism.<br> <span style="color:#ffffff;"><b><span style="background:#1f497d"><span style="letter-spacing:-.1pt">Results:</span></span></b> </span>Of 100 samples examined, 22 samples (22%) showed contamination with <i>L. monocytogenes</i>. Of these, 16 (72.7%) belonged to lineage II, one (4.5%) belonged to lineage III, and the remaining 5 (22.7%) did not belong to any of the three lineages studied. Moreover, three positive samples were related to the environmental samples (water and soil).<br> <span style="color:#ffffff;"><b><span style="background:#1f497d"><span style="letter-spacing:-.1pt">Conclusion:</span></span></b></span> The study showed lineage II as the most common lineage in the examined samples. Moreover, the results emphasized the importance of monitoring <i>L. monocytogenes</i> contamination in food and environment to improve control strategies and ensure food safety.</span></span></p> Environmental Microbiology, Food Microbiology, Listeria monocytogenes, Listeriolysin O, MAMA-PCR 40 49 http://ijmm.ir/browse.php?a_code=A-10-2645-1&slc_lang=en&sid=1 Mahdis Mohammadjani Mahdis.mohammadjani7676@gmail.com 100319475328460031145 100319475328460031145 No Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran Naser Harzandi naser.harzandi@kiau.ac.ir 100319475328460031146 100319475328460031146 Yes Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran Azam Haddadi Haddadi@kiau.ac.ir 100319475328460031147 100319475328460031147 No Department of Microbiology, Karaj Branch, Islamic Azad University, Karaj, Iran