en بررسی اثر ضد میکروبی لاکتوباسیلوس کازئی بر کلبسیلا پنومونیه و اشریشیا کلی جدا شده از نمونه های ادراری ميكروبیولوژی Microbiology پژوهشي Research <div style="text-align: justify;"><span style="font-size:12pt"><span style="line-height:normal"><span new="" roman="" style="font-family:" times=""><b><u><span style="background:white"><span style="color:#1f497d"><span style="letter-spacing:-.2pt">Background & Objectives</span></span></span><span style="color:#1f497d">:</span></u></b> Urinary tract infection (UTI) is a serious issue affecting both men and women resulting from the invasion of microbial agents into the urinary system. This study aimed to investigate the antimicrobial activity of <i>Lactobacillus casei</i> (<i>L. casei</i>) against <i>Klebsiella pneumoniae</i> (<i>K. pneumoniae</i>) and <i>Escherichia coli</i> (<i>E. coli</i>) isolated from UTI.</span></span></span><br> <span style="font-size:12pt"><span style="line-height:normal"><span new="" roman="" style="font-family:" times=""><b><u>Materials & Methods:</u></b> In this study, 100 urine specimens were obtained from medical laboratories in western Tehran. <em>E. coli</em> and <em>K. pneumoniae</em> isolates were identified and subsequently confirmed using polymerase chain reaction (PCR). Antibiotic susceptibility patterns were determined using the disk diffusion method. The antimicrobial activity of <em>L. casei</em> against these strains (four multidrug-resistant isolates from each species) was then evaluated using the agar well diffusion method.</span></span></span><br> <span style="font-size:12pt"><span style="line-height:normal"><span new="" roman="" style="font-family:" times=""><b><u><span style="background:white"><span style="color:#1f497d"><span style="letter-spacing:-.2pt">Results</span></span></span><span style="color:#1f497d">:</span></u></b> <strong>From</strong> 100 urine specimens, 76 <em>E. coli</em> and 14 <em>K. pneumoniae</em> isolates were identified. <strong>Antimicrobial susceptibility testing</strong> revealed that imipenem and nitrofurantoin were the most effective antibiotics against <em>E. coli</em>, while amikacin <strong>demonstrated the highest efficacy</strong> against <em>K. pneumoniae</em>. <strong>In the agar well diffusion assay</strong>, <em>L. casei</em> <strong>generated</strong> growth inhibition zones <strong>measuring</strong> 19.8 mm &plusmn; 3 <strong>for</strong> <em>E. coli</em> and 20.3 mm &plusmn; 4 <strong>for</strong> <em>K. pneumoniae</em>.</span></span></span><br> <span style="font-size:12pt"><span style="line-height:normal"><span new="" roman="" style="font-family:" times=""><b><u><span style="background:white"><span style="color:#1f497d"><span style="letter-spacing:-.2pt">Conclusions:</span></span></span></u></b><i> <em>Lactobacillus casei</em></i> demonstrates notable antimicrobial efficacy against both <em>E. coli</em> and <em>K. pneumoniae</em>, suggesting its potential as an alternative therapeutic option for UTIs.</span></span></span><br> &nbsp;</div> Lactobacillus casei, Escherichia coli, Klebsiella pneumoniae, Urinary Tract Infection, Probiotics 94 103 http://jabs.fums.ac.ir/browse.php?a_code=A-10-3366-1&slc_lang=en&sid=1 Mozhgan Fateh مژگان فاتح mozhganfateh@gmail.com 100319475328460028982 0009-0007-6317-914x No Department of Microbiology, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran گروه میکروبیولوژی، واحد شهرقدس، دانشگاه آزاد اسلامی، تهران، ایران Fatemeh Forohi فاطمه فروهی f_foroohi@ymail.com 100319475328460028983 100319475328460028983 Yes Department of Microbiology, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran گروه میکروبیولوژی، واحد شهرقدس، دانشگاه آزاد اسلامی، تهران، ایران Fatemeh Rafiee فاطمه رفیعی rafiee_ar@yahoo.com 100319475328460028984 100319475328460028984 No Department of Microbiology, Shahr-e-Qods Branch, Islamic Azad University, Tehran, Iran گروه میکروبیولوژی، واحد شهرقدس، دانشگاه آزاد اسلامی، تهران، ایران