High-level fluoroquinolone-resistant clinical isolates of Escherichia coli overproduce multidrug efflux protein AcrA.
نویسندگان
چکیده
Immunoblotting with antibody against AcrA, an obligatory component of the AcrAB multidrug efflux system, showed that this protein was overexpressed by >/=170% in 9 of 10 clinical isolates of Esherichia coli with high-level ciprofloxacin resistance (MICs, >/=32 microg/ml) but not in any of the 15 isolates for which the MIC was </=1 microg/ml.
منابع مشابه
Detection of Efflux Pumps Genes in Fluoroquinolones Resistant and Sensitive strains of Escherichia coli isolated from Patients with Urinary Tract Infection in Qom
Abstract Background and Objectives: Efflux pumps are one of the main mechanisms for antibiotic resistance in Escherichia coli strains. The aim of this study was to investigate the relationship between 5 different efflux pump genes; acrA, acrB, emrA, emrB and mdtk and fluoroquinolone resistance in E.coli Isolated from patients with urinary tract infections in Qom. Methods: In this descriptive cr...
متن کاملGenetic characterization of highly fluoroquinolone-resistant clinical Escherichia coli strains from China: role of acrR mutations.
The genetic basis for fluoroquinolone resistance was examined in 30 high-level fluoroquinolone-resistant Escherichia coli clinical isolates from Beijing, China. Each strain also demonstrated resistance to a variety of other antibiotics. PCR sequence analysis of the quinolone resistance-determining region of the topoisomerase genes (gyrA/B, parC) revealed three to five mutations known to be asso...
متن کاملContribution of the AcrAB-TolC efflux pump to high-level fluoroquinolone resistance in Escherichia coli isolated from dogs and humans.
Fluoroquinolone resistance is mainly caused by mutations in quinolone resistance-determining regions of DNA gyrase and topoisomerase IV in Escherichia coli. The AcrAB-TolC efflux pump contributes to resistance against fluoroquinolone and other antimicrobials. In this study, we investigated a high-level mechanism of fluoroquinolone resistance in E. coli that was isolated from human clinical samp...
متن کاملMechanisms accounting for fluoroquinolone resistance in Escherichia coli clinical isolates.
Fluoroquinolone MICs are increased through the acquisition of chromosomal mutations in the genes encoding gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE), increased levels of the multidrug efflux pump AcrAB, and the plasmid-borne genes aac(6')-Ib-cr and the qnr variants in Escherichia coli. In the accompanying report, we found that ciprofloxacin, gatifloxacin, levofloxacin, and norf...
متن کاملAcrAB Efflux System: Expression and Contribution to Fluoroquinolone Resistance in Klebsiella spp.
Seven Klebsiella pneumoniae and four Klebsiella oxytoca clinical isolates with different levels of resistance to ciprofloxacin were studied. Mutations in the topoisomerase genes were found in almost all strains, but the contribution of a multidrug efflux system homologous to AcrAB in Escherichia coli was also observed. Overexpression of this efflux system was demonstrated by immunoblotting with...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Antimicrobial agents and chemotherapy
دوره 44 12 شماره
صفحات -
تاریخ انتشار 2000