ArticleAntimicrobial agents and chemotherapy2015
Mutations That Enhance the Ciprofloxacin Resistance of Escherichia coli with qnrA1.
Article in Antimicrobial agents and chemotherapy, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 27 papers, 1 of them a synthesis that pooled it.
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Who cites it
27 citing papers in PubMed, 1 synthesis or guideline pooled it, 46 citations in OpenAlex.
- Plasmid-mediated quinolone resistance in Enterobacteriaceae: a systematic review with a focus on Mediterranean countries.European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology · 2017Pooled it
- Determination of frequency of spontaneous resistance for gepotidacin and levofloxacin against a collection of gram-positive and gram-negative organisms.Antimicrobial agents and chemotherapy · 2026Article
- Molecular Epidemiology and Multilevel Drug Resistance Mechanisms ofInfection and drug resistance · 2026Review
- Uncommon Pathogens in Common Presentations: Genetic Profiling and Virulence Determinants ofInfectious disease reports · 2025Article
- Detection of Delafloxacin Resistance Mechanisms in Multidrug-ResistantAntibiotics (Basel, Switzerland) · 2025Article
- Navigating fluoroquinolone resistance in Gram-negative bacteria: a comprehensive evaluation.JAC-antimicrobial resistance · 2024Review
- Short reads-based characterization of pathotype diversity and drug resistance among Escherichia coli isolated from patients attending regional referral hospitals in Tanzania.BMC medical genomics · 2024Article
- Unusual and Unconsidered Mechanisms of Bacterial Resilience and Resistance to Quinolones.Life (Basel, Switzerland) · 2024Review
- Antibiotic susceptibility among non-clinicalHeliyon · 2022Review
- Review
- Biological Effects of Quinolones: A Family of Broad-Spectrum Antimicrobial Agents.Molecules (Basel, Switzerland) · 2021Review
- Article
- Limited Multidrug Resistance Efflux Pump Overexpression among Multidrug-Resistant Escherichia coli Strains of ST131.Antimicrobial agents and chemotherapy · 2021Article
- Outcome of Different Sequencing and Assembly Approaches on the Detection of Plasmids and Localization of Antimicrobial Resistance Genes in CommensalMicroorganisms · 2021Article
- Prevalence and Characteristic of Swine-OriginFrontiers in microbiology · 2021Article
- Genes and Proteomes Associated With Increased Mutation Frequency and Multidrug Resistance of Naturally Occurring Mismatch Repair-DeficientFrontiers in microbiology · 2020Article
- Synergistic Activity of Fluoroquinolones Combining with Artesunate Against Multidrug-ResistantMicrobial drug resistance (Larchmont, N.Y.) · 2020Article
- Transferable Mechanisms of Quinolone Resistance from 1998 Onward.Clinical microbiology reviews · 2019Review
- Multiple Copies ofAntimicrobial agents and chemotherapy · 2019Article
- The plasmid-borne quinolone resistance protein QnrB, a novel DnaA-binding protein, increases the bacterial mutation rate by triggering DNA replication stress.Molecular microbiology · 2019Article
Corrections and comments
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Authors and funding
4 authors at 2 institutions in 1 country.
Funding
Abstract
Plasmid-mediated qnr genes provide only a modest decrease in quinolone susceptibility but facilitate the selection of higher-level resistance. In Escherichia coli strain J53 without qnr, ciprofloxacin resistance often involves mutations in the GyrA subunit of DNA gyrase. Mutations in gyrA were absent, however, when 43 mutants with decreased ciprofloxacin susceptibility were selected from J53(pMG252) with qnrA1. Instead, in 13 mutants, individual and whole-genome sequencing identified mutations in marR and soxR associated with increased expression of marA and soxS and, through them, increased expression of the AcrAB pump, which effluxes quinolones. Nine mutants had increased expression of the MdtE efflux pump, and six demonstrated increased expression of the ydhE pump gene. Many efflux mutants also had increased resistance to novobiocin, another pump substrate, but other mutants were novobiocin hypersusceptible. Mutations in rfaD and rfaE in the pathway for inner core lipopolysaccharide (LPS) biosynthesis were identified in five such strains. Many of the pump and LPS mutants had decreased expression of OmpF, the major porin channel for ciprofloxacin entry. Three mutants had increased expression of qnrA that persisted when pMG252 from these strains was outcrossed. gyrA mutations were also rare when mutants with decreased ciprofloxacin susceptibility were selected from E. coli J53 with aac(6')-Ib-cr or qepA. We suggest that multiple genes conferring low-level resistance contribute to enhanced ciprofloxacin resistance selected from an E. coli strain carrying qnrA1, aac(6')-Ib-cr, or qepA because these determinants decrease the effective ciprofloxacin concentration and allow more common but lower-resistance mutations than those in gyrA to predominate.
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Registered trials
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