en ميکروبيولوژي Microbiology پژوهشي Research <div style="text-align: justify;"><strong>Background:</strong> A most common opportunistic pathogen, <em>Pseudomonas aeruginosa</em> is present in both humans and animals and responsible for various nosocomial infections and healthcare settings related infections. Different virulence genes like; <em>oprL</em> (membrane lipoprotein L) and <em>toxA</em> (exotoxin A i.e. ETA) in <em>P. aeruginosa</em>, assist in its pathogenicity, toxicity and contribute to high antibiotic resistance. So considering the risk of zoonotic transmission of <em>P. aeruginosa</em> through animal-related foods, this study aimed to monitor the prevalence of <em>oprL </em>and <em>toxA</em> virulence genes and antimicrobial resistance in <em>P. aeruginosa</em> isolates, obtained from animal (Cow&rsquo;s milk) and human clinical samples.</div> <div style="text-align: justify;"><strong>Material and methods: </strong>Of the total 120 collected samples for this study, every 60 samples were collected from animals and humans from respective laboratories. Total 76 isolates of <em>P. aeruginosa</em> were isolated and identified by morphological and biochemical tests. The presence of virulence factors like <em>oprL</em> and <em>toxA</em> were evaluated by PCR analysis and antimicrobial resistance was assessed by antibiotic susceptibility test (Kirby-Bauer method). &nbsp;</div> <div style="text-align: justify;"><strong>Results:</strong> From the total 76, <em>P. aeruginosa</em> isolates obtained from both animal and human isolates, alone presence and coexistence of both <em>toxA</em> and <em>oprL</em> genes in <em>P. aeruginosa</em> isolates; were detected in PCR analysis. PCR analysis results showed in <em>P. aeruginosa</em> isolates, alone distribution of <em>toxA</em> and <em>oprL </em>genes is, 75% and 54.16% in animals, and 84.61% and 80.76% in humans, respectively. The coexistence of both genes was 37.50% and 40.32% in animals and human isolates, along with high antibiotic resistance in most <em>P. aeruginosa</em> isolates.</div> <strong>Conclusion:</strong> Therefore, this study suggested PCR analysis can be used for fast and specific detection of <em>oprL</em> and <em>toxA</em> genes in <em>P. aeruginosa.</em> Monitoring of these genes can help to prevent the risk of transmission of multi-drug resistant <em>P. aeruginosa</em>, from animals to humans. Pseudomonas aeruginosa, Antibiotic resistance, Virulence factors, Polymerase chain reaction (PCR), toxA, oprL, ExotoxinA (ETA) 245 252 http://rmm.mazums.ac.ir/browse.php?a_code=A-10-820-6&slc_lang=en&sid=1 Ciamak Ghazaei ciamakghazaei@yahoo.com 100319475328460010914 100319475328460010914 Yes Department of Microbiology, University of Mohaghegh Ardabili, Ardabil, Iran.