distribution of ciprofloxacin-resistance genes among st131 and non-st131 clones of escherichia coli isolates with esbl phenotypes isolated from women with urinary tract infection

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 (cip^r/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) cip^r/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%), bla ctx-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 cip^r/esbl^+ isolates (st131) co-harbored pmqr, esbl, and chromosomal mutations, is important for their effective therapy