en ویروس شناسی پزشکی Medical Virology مقاله پژوهشی Original Research Article <p style="text-align: justify;"><span style="font-size:16px;"><span style="font-family:Times New Roman;"><b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Background and Aim:</span></span></span></b><span style="color:black">&nbsp;</span></span><span style="color:#000000;"><span style="line-height:150%"><span style="font-family:Calibri,sans-serif"><span lang="EN"><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">The high occurrence rate of antibiotic-resistant <i>Helicobacter (H.) pylori</i> has led to consideration of novel therapeutic approaches. This study aimed to isolate and characterize a bacteriophage against antibiotic-resistant strains of <i>H. pylori</i> isolates from gastric biopsies of patients.</span></span></span></span></span></span><br> <span style="font-family:Times New Roman;"><b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Materials and Methods:</span></span></span></b><span style="color:black"> </span></span><span style="color:#000000;"><span style="line-height:150%"><span style="font-family:Calibri,sans-serif"><span lang="EN"><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">Untreated wastewater was collected from Imam Hossein, Taleghani, and Mofid Children&rsquo;s Hospitals and mixed together. The presence of bacteriophage was confirmed by double-layer agar technique. Transmission Electron Microscope (TEM) was used to determine the morphology of the isolated phage. In addition, stability tests were performed. The host range and multiplicity of infection (MOI) of bacteriophages were determined. Finally, the phage genome was extracted and its concentration was calculated using a Nanodrop spectrophotometer.</span></span></span></span></span></span><span style="font-family:Times New Roman;"><span style="color:black"> </span><br> <b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Results:</span></span></span></b><span style="color:black"> </span></span><span style="color:#000000;"><span style="line-height:150%"><span style="font-family:Calibri,sans-serif"><span lang="EN"><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">TEM micrograph showed that the isolated phage belonged to the <i>Caudoviricetes</i><i> </i>class and had Podoviridae-like morphology. It was effective against 9 clinical strains of <i>H. pylori</i> and the standard strain of <i>Campylobacter jejuni</i>. The optimal activity of this phage was at 37&deg;C and pH 4 to 7. This phage was sensitive to chloroform, and was stable with increasing salt concentration. It was revealed that MOI=1 was optimal for this bacteriophage activity.</span></span></span></span></span></span><br> <span style="font-family:Times New Roman;"><b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Conclusion:</span></span></span></b><span style="color:black">&nbsp;</span></span><span style="color:#000000;"><span style="line-height:150%"><span style="font-family:Calibri,sans-serif"><span lang="EN"><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">In conclusion, the isolated phage was effective against antibiotic-resistant strains of<i> H. pylori </i>isolates from gastric biopsies of patients. It can be considered a suitable candidate for further </span></span></span><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">genomic and <i>in vivo</i> </span></span><span lang="EN"><span style="line-height:150%"><span new="" roman="" style="font-family:" times="">studies.</span></span></span></span></span></span></span></p> Antibiotic Resistance, Campylobacter jejuni, Caudoviricetes, H. pylori, Phage Therapy, Podoviridae 389 402 http://ijmm.ir/browse.php?a_code=A-10-2160-3&slc_lang=en&sid=1 Yasaman Zahra Mohseni yasamanmohseni1020@gmail.com 100319475328460033905 100319475328460033905 No Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran Ameneh Elikaei a.elikaei@alzahra.ac.ir 100319475328460033906 100319475328460033906 Yes Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran Bahareh Attaran attaran.b@gmail.com 100319475328460033907 100319475328460033907 No Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran Mahsa Soltani mahsasoltani123@gmail.com 100319475328460033908 100319475328460033908 No Department of Microbiology, Faculty of Biological Sciences, Alzahra University, Tehran, Iran