Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 12 3 2020 05 29 223 230 Mahdis Ghavidel Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran AND Department of Microbiology and Virology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran Tahere Gholamhosseini-Moghadam Department of Veterinary Medicine, Shiraz University, Shiraz, Iran Kimiya Nourian Department of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad, Iran Kiarash Ghazvini Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran AND Department of Microbiology and Virology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran 2019 06 09 2020 04 02 Background and Objectives: Escherichia coli is known to be the pathogen commonly isolated from those infected with urinary tract infections (UTIs). The aim of this study was to investigate the presence of E. coli virulence genes and antibiotics’ resistance pattern among clinical isolates in the Northeast of Iran. Relationships between virulence genes and antimicrobial resistances were studied as well. Materials and Methods: Three hundred isolates of E. coli were isolated from patients with UTIs that referred to Ghaem and Imam Reza hospitals (Mashhad, Iran) during August 2016 to February 2017. A multiplex PCR was employed to amplify the genes encoding pyelonephritis associated pili (pap), S-family adhesions (sfa), type1fimbriae (fimH) and aerobactin (aer). Disk diffusion test was performed to test the susceptibility of isolates to β-lactams, aminoglycosides, cephalosporins, quinolone, fluoroquinolones, carbapenems and trimethoprim-sulfamethoxazole. Results: The PCR results identified the fimH in 78.4%, aer in 70.5%, sfa in 13.6% and the pap in 8.2% of isolates. The rates of antibiotic resistance of the isolates were as follows: 64.7% resistant to cephalosporins, 34% to trimethoprim-sulfamethoxazole, 31% to fluoroquinolones, 15.3% to aminoglycosides, 13.3% to β-lactams, 7.8% to quinolones and 4.4% to carbapenems. Significant relationships existed between pap and aer, pap and sfa, aer and fluoroquinolones also pap and cephalosporins. Conclusion: fimH and aer were found in > 50% of isolates suggesting the importance of both genes in UPEC. The majority of isolates had fimH as adhesion factor for colonization. Determining antibiotic resistance patterns in specific geographical areas is necessary for appropriate treatment of urinary tract infection. The high rate of resistance to cephalosporins is most likely due to incorrect drug administration. https://ijm.tums.ac.ir/index.php/ijm/article/view/2206 https://ijm.tums.ac.ir/index.php/ijm/article/download/2206/1245