en ميکروبيولوژي Microbiology پژوهشي Research <div style="text-align: justify;"><strong>Background: </strong><em>Acinetobacter baumannii</em> is a highly virulent bacterium. It causes opportunistic and nosocomial infections and is a threat to healthcare settings. It has also developed multidrug resistance (MDR) capacity. The nosocomial bacteria and antibiotic resistance are primordial and a significant public health concern. These bacteria and their threat can be prevented by reducing infected foodstuffs. Thus, in this study, we investigated&nbsp;<em>A. </em><em>baumannii</em> isolated from foods in Ardabil City, Iran, and assessed their antibiotic resistance patterns.<br> <strong>Materials and methods:</strong> The identification of bacterium was made by cell morphological and biochemical tests, including sulfide indole motility medium, Simmons citrate agar, the triple sugar Iron test, urease, catalase and oxidase test. Also, gene <em>BlaOXA-51</em> was targeted with the polymerase chain reaction test to select potential MDR strains. The disk diffusion method was used to evaluate the antibiotic susceptibility of the isolates. For the detection of antibiotic resistance genes, &beta;-lactamase was conducted with phenotypic and genotypic assays using the combined disk test and PCR.<br> <strong>Results:</strong> Among 100 samples, 27 strains of <em>A. baumannii</em> were isolated. Some antibiotics like imipenem showed 100% sensitivity, and ampicillin-sulbactam showed 100% resistance to isolates. Also, a multidrug resistance profile was assessed and the antibiotic-resistance &beta;-lactamase genes were detected. The prevalence of genes encoding extended-spectrum &beta;-lactamase in the isolates were as follows: <em>SHV</em>, 29.62%; <em>TEM</em>, 18.51%; <em>PER</em>, 14.81%.<br> <strong>Conclusion:</strong> <em>A. baumannii</em> isolates showed the highest resistance towards ampicillin-sulbactam (100%) and the lowest resistance to imipenem (0%).These results emphasize the importance of detection and implementation of control measures to prevent the spread of <em>A. baumannii </em>in foodstuffs.</div> Acinetobacter baumannii, Antibiotic resistance, Infection, β-Lactamase 25 32 http://rmm.mazums.ac.ir/browse.php?a_code=A-10-820-2&slc_lang=en&sid=1 Ciamak Ghazaei ciamakghazaei@yahoo.com 10031947532846008527 10031947532846008527 Yes Department of Microbiology, University of Mohaghegh Ardabili, Ardabil, Iran