en باکتری شناسی Bactriology پژوهشي Research <div style="text-align: justify;"><span style="font-family:Times New Roman;"><span style="font-size:12pt"><span style="line-height:115%"><span new="" roman="" times=""><span style="color:black"><b><span style="font-size:10.0pt"><span style="line-height:115%">Background and Aims: </span></span></b><span style="font-size:10.0pt"><span style="line-height:115%">In the current study, two bacteriophages were isolated from the wastewater sources and characterized by lytic activity against the<i> Listeria monocytogenes</i> (<i>L.</i> <i>monocytogenes</i>) bacterium.</span></span></span></span></span></span><br> <span style="font-size:12pt"><span style="line-height:115%"><span new="" roman="" times=""><span style="color:black"><b><span style="font-size:10.0pt"><span style="line-height:115%">Materials and Methods<strong>:</strong></span></span></b><span style="font-size:10.0pt"><span style="line-height:115%">&nbsp; 50 wastewater samples were collected from the disposal sites. The phages were isolated from the treated samples using the double agar overlay method with <i>L. monocytogenes</i> as the host bacterium. Plaque morphology, temperature, pH, titration of phage lysate, host range, and scanning electron microscopic morphology were used to characterize the isolated phages.</span></span></span></span></span></span><br> <span style="font-size:12pt"><span style="line-height:115%"><span new="" roman="" times=""><span style="color:black"><b><span style="font-size:10.0pt"><span style="line-height:115%">Results<strong>:&nbsp;</strong></span></span></b><span style="font-size:10.0pt"><span style="line-height:115%">Bacteriophage was found in two samples taken from wastewater treatment plants. Phages were proliferated and released under optimal bacterial growth conditions at pH 7; 37 &deg;C in 36-hour incubation. A 10:1 ratio of bacterial cells to phage produced&nbsp;<span style="letter-spacing:.2pt">the greatest lytic ability. The highest phage titrated under optimal conditions was estimated at 9&times;10⁹ pfu/ml. The scanning&nbsp;</span>electron microscopic image revealed a bacteriophage&nbsp;morphology corresponding to the head and tail group. The host range observations demonstrated that <i>L. monocytogenes</i> were unique to the isolated phage. The elimination of <i>L. monocytogenes</i> growth in milk and whey samples revealed that this bacteriophage targeted bacteria and resulted in a 75% reduction in bacterial contamination.</span></span></span></span></span></span><br> <b><span style="font-size:10.0pt"><span new="" roman="" times="">Conclusion<strong>:&nbsp;</strong></span></span></b><span style="font-size:10.0pt"><span new="" roman="" times="">The results suggest that the phages obtained from <i>L. monocytogenes</i> may be utilized to combat this pathogen in dairy, agri-food, wastes, and other associated infections.</span></span></span></div> Bacteriophage, Food safety, Listeria monocytogenes, Phage therapy, Wastewater 17 25 http://ijml.ssu.ac.ir/browse.php?a_code=A-10-468-1&slc_lang=en&sid=1 Abdolrazagh Marzban عبدالرزاق مرزبان marzban86@gmail.com 0000-0002-2027-8910 No Razi Herbal Medicines Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran Marjan Beiranvand مرجان بیرانوند mar2309101368@gmail.com 0000-0002-5068-0142 No Department of Biology, Khorramabad Branch. Azad University, Khorramabad, Iran. Samaneh Sedighi-Khavidak سمانه صدیقی خویدک sedighi.samaneh@yahoo.com 0000-0002-2177-7340 Yes Medical Biotechnology Research Center, Department of Biology, Ashkezar Branch, Azad University, Ashkezar, Yazd, Iran.