ArticleAntimicrobial agents and chemotherapy2009
Mechanisms accounting for fluoroquinolone resistance in Escherichia coli clinical isolates.
Article in Antimicrobial agents and chemotherapy, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 88 papers, 1 of them a synthesis that pooled it.
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Who cites it
88 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Large-scale assessment of antimicrobial resistance marker databases for genetic phenotype prediction: a systematic review.The Journal of antimicrobial chemotherapy · 2020Pooled it
- Novel Bacterial Topoisomerase Inhibitors: A New Front in an Old War.Journal of molecular biology · 2026Review
- The effect of biochanin A on the antibiotic susceptibilities of Escherichia coli grown under different respiration and metabolic conditions on agar media.BMC microbiology · 2026Article
- Analysis of GyrA gene mutations in environmental Escherichia coli: understanding the mechanisms and spread of quinolone resistance in ecosystems.Die Naturwissenschaften · 2026Article
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- A Comprehensive Review on Discovery, Development, the Chemistry of Quinolones, and Their Antimicrobial Resistance.Current topics in medicinal chemistry · 2026Review
- The effect of commonly used non-antibiotic medications on antimicrobial resistance development in Escherichia coli.npj antimicrobials and resistance · 2025Article
- The diverse phenotypic and mutational landscape induced by fluoroquinolone treatment.mSystems · 2025Article
- Mechanisms of fluoroquinolone resistance among Escherichia coli isolates from urinary tract infections in Thailand.PloS one · 2025Article
- Navigating an evolving microbial landscape: emerging antimicrobial resistance trends and precision stewardship in Tianjin tertiary hospitals (2021-2023).Frontiers in cellular and infection microbiology · 2025Article
- Macrolones target bacterial ribosomes and DNA gyrase and can evade resistance mechanisms.Nature chemical biology · 2024Article
- Establishment of an Antimicrobial Stewardship Program to Spare the Use of Oral Fluoroquinolones for Acute Uncomplicated Cystitis in Outpatients.Antibiotics (Basel, Switzerland) · 2024Article
- Unpredictability of the Fitness Effects of Antimicrobial Resistance Mutations Across Environments in Escherichia coli.Molecular biology and evolution · 2024Article
- Gyrase and Topoisomerase IV: Recycling Old Targets for New Antibacterials to Combat Fluoroquinolone Resistance.ACS infectious diseases · 2024Review
- Interactions between Gepotidacin andACS infectious diseases · 2024Article
- Constitutive Activation of RpoH and the Addition of L-arabinose Influence Antibiotic Sensitivity of PHL628Antibiotics (Basel, Switzerland) · 2024Article
- The influence of oxygen and oxidative stress on de novo acquisition of antibiotic resistance in E. coli and Lactobacillus lactis.BMC microbiology · 2023Article
- Prevalence and Characterization of Extended-Spectrum β-Lactamase-ProducingAntibiotics (Basel, Switzerland) · 2023Article
- Role of the Water-Metal Ion Bridge in Quinolone Interactions withInternational journal of molecular sciences · 2023Article
28 more citing papers are in PubMed but not listed here.
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4 authors.
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Abstract
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 norfloxacin MICs for fluoroquinolone-resistant E. coli clinical isolates were very high and widely varied (L. Becnel Boyd, M. J. Maynard, S. K. Morgan-Linnell, L. B. Horton, R. Sucgang, R. J. Hamill, J. Rojo Jimenez, J. Versalovic, D. Steffen, and L. Zechiedrich, Antimicrob. Agents Chemother. 53:229-234, 2009). Here, we sequenced gyrA, gyrB, parC, and parE; screened for aac(6')-Ib-cr and qnrA; and quantified AcrA levels in E. coli isolates for which patient sex, age, location, and site of infection were known. We found that (i) all fluoroquinolone-resistant isolates had gyrA mutations; (ii) approximately 85% of gyrA mutants also had parC mutations; (iii) the ciprofloxacin and norfloxacin MICs for isolates harboring aac(6')-Ib-cr ( approximately 23%) were significantly higher, but the gatifloxacin and levofloxacin MICs were not; (iv) no isolate had qnrA; and (v) approximately 33% of the fluoroquinolone-resistant isolates had increased AcrA levels. Increased AcrA correlated with nonsusceptibility to the fluoroquinolones but did not correlate with nonsusceptibility to any other antimicrobial agents reported from hospital antibiograms. Known mechanisms accounted for the fluoroquinolone MICs of 50 to 70% of the isolates; the remaining included isolates for which the MICs were up to 1,500-fold higher than expected. Thus, additional, unknown fluoroquinolone resistance mechanisms must be present in some clinical isolates.
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