ArticlePloS one2009
Efflux pump, the masked side of beta-lactam resistance in Klebsiella pneumoniae clinical isolates.
Article in PloS one, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 60 papers.
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Who cites it
60 citing papers in PubMed.
- Klebsiella pneumoniae in the global AMR: resistance mechanisms and genomic adaptation.World journal of microbiology & biotechnology · 2026Review
- Prevalence and Determinants of Multi-Drug Resistance Bacterial Infection Among Burn Patients in a Tertiary Care Center in Nepal.Infection and drug resistance · 2026Article
- Strain-dependent contribution of the AcrAB-TolC efflux pump toMicrobiology (Reading, England) · 2025Article
- Small excretory-secretory proteins of Acanthamoeba castellanii genotype T4 upregulate the expression of capsule-associated genes via the Rcs two-component system in Klebsiella pneumoniae.Parasites & vectors · 2025Article
- A novel role for colistin as an efflux pump inhibitor in multidrug-resistant Klebsiella pneumoniae.Scientific reports · 2025Article
- Bacterial strain type and TEM-1 enzyme allele impact antibiotic susceptibility distribution in monoclonal populations: a single-cell droplet approach.Royal Society open science · 2025Article
- Antibiotic Resistance, Virulence Genes, and Molecular Diversity of ClinicalPathogens (Basel, Switzerland) · 2025Article
- Antimicrobial resistance, biofilm formation, and molecular detection of efflux pump and biofilm genes amongHeliyon · 2024Article
- Semi-mechanistic modeling of resistance development to β-lactam and β-lactamase-inhibitor combinations.Journal of pharmacokinetics and pharmacodynamics · 2024Article
- Cold Plasma Deposition of Tobramycin as an Approach to Localized Antibiotic Delivery to Combat Biofilm Formation.Pathogens (Basel, Switzerland) · 2024Article
- Haematological Profile and Antibiotic Resistance of Bacteria Responsible for Enteric Infections Isolated From Patients Suffering From Malaria and Enteric Infections on Consultation at the Dschang Regional Hospital.The Canadian journal of infectious diseases & medical microbiology = Journal canadien des maladies infectieuses et de la microbiologie medicale · 2024Article
- Article
- Exploring the Antibiotic Resistance Profile of ClinicalAntibiotics (Basel, Switzerland) · 2022Article
- Mutations inAntimicrobial agents and chemotherapy · 2022Article
- Genomic Characterization of International High-Risk Clone ST410Antibiotics (Basel, Switzerland) · 2022Article
- Antibacterial and antibiotic-potentiation activity of the constituents from aerial part of Donella welwitshii (Sapotaceae) against multidrug resistant phenotypes.BMC complementary medicine and therapies · 2022Article
- Role of Efflux Pump-Mediated Antibiotic Resistance in Quorum Sensing-Regulated Biofilm Formation byPathogens (Basel, Switzerland) · 2022Article
- Clinical Status of Efflux Resistance Mechanisms in Gram-Negative Bacteria.Antibiotics (Basel, Switzerland) · 2021Review
- Metallo-β-lactamases in the Age of Multidrug Resistance: From Structure and Mechanism to Evolution, Dissemination, and Inhibitor Design.Chemical reviews · 2021Review
- QPX7728, An Ultra-Broad-Spectrum B-Lactamase Inhibitor for Intravenous and Oral Therapy: Overview of Biochemical and Microbiological Characteristics.Frontiers in microbiology · 2021Review
Corrections and comments
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7 authors.
Funding
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Abstract
backgroundBeta-lactamase production and porin decrease are the well-recognized mechanisms of acquired beta-lactam resistance in Klebsiella pneumoniae isolates. However, such mechanisms proved to be absent in K. pneumoniae isolates that are non susceptible to cefoxitin (FOX) and susceptible to amoxicillin+clavulanic acid in our hospital. Assessing the role of efflux pumps in this beta-lactam phenotype was the aim of this study. METHODOLOGY/
findingsMICs of 9 beta-lactams, including cloxacillin (CLX), and other antibiotic families were tested alone and with an efflux pump inhibitor (EPI), then with both CLX (subinhibitory concentrations) and EPI against 11 unique bacteremia K. pneumoniae isolates displaying the unusual phenotype, and 2 ATCC strains. CLX and EPI-dose dependent effects were studied on 4 representatives strains. CLX MICs significantly decreased when tested with EPI. A similar phenomenon was observed with piperacillin+tazobactam whereas MICs of the other beta-lactams significantly decreased only in the presence of both EPI and CLX. Thus, FOX MICs decreased 128 fold in the K. pneumoniae isolates but also 16 fold in ATCC strain. Restoration of FOX activity was CLX dose-dependent suggesting a competitive relationship between CLX and the other beta-lactams with regard to their efflux. For chloramphenicol, erythromycin and nalidixic acid whose resistance was also due to efflux, adding CLX to EPI did not increase their activity suggesting differences between the efflux process of these molecules and that of beta-lactams.
conclusionThis is the first study demonstrating that efflux mechanism plays a key role in the beta-lactam susceptibility of clinical isolates of K. pneumoniae. Such data clearly evidence that the involvement of efflux pumps in beta-lactam resistance is specially underestimated in clinical isolates.
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