Search

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 (CIP R ) 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., (Copyright © 2021 The Authors. Published by Tehran University of Medical Sciences.)

Background and Objectives: The appearance of antibiotic resistance in Streptococcus pneumoniae has raised a global concern over the past three decades. This study was conducted to determine the antimicrobial susceptibility of S. pneumoniae isolated from patients in Children´s Medical Center (CMC) Hospital during 2001 to 2011., Materials and Methods: During the 11 years period, a total of 194 S. pneumoniae isolates were collected in CMC Hospital. Antimicrobial susceptibility testing was performed by the Kirby-Bauer disk diffusion method and time-series analysis was used to evaluate the antimicrobial susceptibility changes over the time., Results and Conclusion: Antimicrobial susceptibility of S. pneumoniae to different antibiotics decreased from 2001 to 2011 as: penicillin from 78% to 32%, erythromycin from 75% to 35%, chloramphenicol from 94% to 55%, ampicillin from 70% to 62%, ceftriaxone from 100% to 87%, sulfametoxazole from 57% to 40%. We did not find any significant difference between the susceptibility of isolates from sterile and non-sterile sources. It would be an important key to consider antimicrobial stewardship as an essential factor to prevent the development of antimicrobial resistance.