en مقاومت پادزیستی (آنتی بیوتیکی) Antibiotic Resistance 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 lang="EN-ID">Nanoemulsion technology is considered one of the most advanced and targeted drug delivery systems. This study aimed to evaluate the efficacy of a trimethoprim-based nanoemulsion against <em>Proteus mirabilis</em> isolated from urinary tract infections (UTIs).</span><br> <b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Materials and Methods:</span></span></span></b> <span lang="EN-ID">A total of 300 urine samples were collected from patients with clinically diagnosed UTIs at Azadi Teaching Hospital. Samples were cultured on blood agar and MacConkey agar. Phenotypic identification was performed, and<em> P. mirabilis </em>was confirmed by detection of the 16S rRNA gene. Antibiotic susceptibility was assessed using the Kirby&ndash;Bauer disk diffusion method. Trimethoprim nanoemulsions were prepared through phase diagram construction, characterized by Fourier-transform infrared spectroscopy (FTIR), zeta potential, and field emission scanning electron microscopy (FESEM), and evaluated for stability and antimicrobial activity.</span><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 lang="EN-ID">Of 175 culture-positive samples, 50 (28.6%) yielded <em>P. mirabilis</em>. PCR confirmed all isolates by amplification of a single 1500-bp 16S rRNA gene fragment. Antimicrobial susceptibility testing showed complete resistance (100%) to ampicillin, 50% resistance to trimethoprim, nalidixic acid, and ciprofloxacin, and 30% resistance to gentamicin. FTIR analysis indicated no major chemical interactions between trimethoprim and excipients, supporting drug stability. FESEM imaging demonstrated a uniform spherical morphology of the nanoemulsion droplets, consistent with high stability and bioactivity. The mean inhibition zone diameter of the trimethoprim nanoemulsion against <em>P. mirabilis</em> was 41.5 mm, significantly greater than that of pure trimethoprim (p < 0.001).</span><br> <b><span style="background:#1f497d"><span style="color:white"><span style="letter-spacing:-.1pt">Conclusion:</span></span></span></b>&nbsp;The All <em>P. mirabilis </em>isolates were fully susceptible to the trimethoprim nanoemulsion, highlighting its potent antibacterial activity and potential as a therapeutic strategy against multidrug-resistant strains.</span></span></p> Urinary Tract Infections, Proteus mirabilis, Nanoemulsion, Gram-Negative Bacteria, Trimethoprim 182 190 http://ijmm.ir/browse.php?a_code=A-10-2547-3&slc_lang=en&sid=1 Sarah Ahmed Hasan sarahahmed100@uokirkuk.edu.iq 100319475328460032286 100319475328460032286 Yes Department of Basic Science, College of Nursing, Kirkuk University, Kirkuk, Iraq