Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 13 3 2021 06 05 294 302 Masoumeh Rasoulinasab Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran Fereshteh Shahcheraghi Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran Mohammad Mehdi Feizabadi Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran; Thoracic Research Center, Imam Khomeini Hospital Complex, Tehran, Iran Bahram Nikmanesh Department of Medical Laboratory Sciences, School of Allied Medical Sciences, Tehran University of Medical Sciences, Tehran, Iran Azade Hajihasani Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran Mohammad Mehdi Aslani Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran 2021 01 20 2021 05 31 Background and Objectives: Escherichia coli (E. coli) sequence type 131 (ST131) is associated with extended-spectrum beta-lactamase (ESBL) production and fluoroquinolone resistance. This study aimed to investigate the prevalence of ST131, ESBL, and plasmid-mediated quinolone resistance (PMQR) genes in the ciprofloxacin-resistant (CIPR) and ESBL producers from women with UTI. Materials and Methods: The CIP-resistant ESBL producing (CIPR/ESBL+) E. coli isolates were screened for ST131-by specific PCR of mdh and gyrB. The ESBL and PMQR genes were screened by single PCR. The ST131 and non-ST131 isolates were selected to determine the mutations of gyrA and parC using PCR and sequencing, and also their genetic background by the Pasteur-MLST scheme. Results: Overall, 55% (33/60) CIPR/ESBL+ isolates were identified as ST131 (94% O25b-ST131). Resistance rate to ampicillin-sulbactam (70%), aztreonam (97%) and gentamicin (61%), the prevalence of aac(6′)-Ib-cr (66%), blaCTX-M-15 (82%), the profile of qnrS+aac(6′)-Ib-cr (30%), and the double mutation in the parC was significantly higher in ST131 than non-ST131 isolates. The coexistence of PMQR and ESBL genes was found in more than 50% of ST131 and non-ST131 isolates. ST131 isolates differentiated into PST43 and PST506. Conclusion: Management of women with UTI caused by the CIPR/ESBL+ isolates (ST131) co-harbored PMQR, ESBL, and chromosomal mutations, is important for their effective therapy. https://ijm.tums.ac.ir/index.php/ijm/article/view/2947 https://ijm.tums.ac.ir/index.php/ijm/article/download/2947/1346