Related Experiment Video
Updated: Jan 31, 2026

The Use of a β-lactamase-based Conductimetric Biosensor Assay to Detect Biomolecular Interactions
Published on: February 1, 2018
Hidden Carbapenem Resistance in OXA-48 and Extended-Spectrum β-Lactamase-Positive Escherichia coli
Maja Tomić Paradžik1,2, Domagoj Drenjančević2,3, Aleksandra Presečki-Stanko4
11 Department of Clinical Microbiology, Institute for Public Health Brod-Posavina County, Slavonski Brod, Croatia.
Abstract:
The purpose of this study was to report the identification OXA-48 carbapenemase in seven extended-spectrum β-lactamase (ESBL)-positive Escherichia coli clinical isolates, fully susceptible to all carbapenems by disk diffusion and E-test methods, but with borderline minimal inhibitory concentration (MIC) values of ertapenem. This report points to the necessity for determination of carbapenem MICs in ESBL-positive E. coli isolates and additional phenotypic testing for carbapenemases in all isolates with borderline ertapenem MIC defined by EUCAST. The isolates showed a high level of resistance to expanded-spectrum cephalosporins because of the production of an additional ESBL belonging to CTX-M family. All isolates and their respective tranconjugants were found to possess L plasmid. Pulsed-field gel electrophoresis analysis revealed two clusters containing highly related isolates. The global spread of multidrug-resistant E. coli should be monitored closely because of the ability of isolates to rapidly obtain additional antibiotic resistance traits such as plasmid-mediated OXA-48 genes.
Related Concept Videos
The Electromagnetic Spectrum
The Electromagnetic Spectrum
IR Spectrum
Transmittance is defined as the ratio of the radiant power passing through a sample to that from the radiation's source. Multiplying the transmittance by 100 gives the percent transmittance (%T), which varies between 100% (no absorption) and 0%...
Mass Spectrum
UV–Vis Spectrum
The UV–Vis spectrum of a molecule is the plot of its absorbance versus wavelength. The plot is drawn by taking molar...
Position-effect Variegation

