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Updated: Aug 7, 2026
08:06
The Use of a β-lactamase-based Conductimetric Biosensor Assay to Detect Biomolecular Interactions
Published on: February 1, 2018
CMT-type beta-lactamase TEM-125, an emerging problem for extended-spectrum beta-lactamase detection
Frédéric Robin1, Julien Delmas, Maryse Archambaud
1CHU Clermont-Ferrand, Laboratoire de Bactériologie, Faculté de Médecine, 63 001 Clermont-Ferrand, France. frobin@chu-clermontferrand.fr
Antimicrobial Agents and Chemotherapy
|June 28, 2006
Summary
A novel beta-lactamase, TEM-125, confers resistance to antibiotics like ceftazidime in Escherichia coli. This enzyme is difficult to detect using standard methods, highlighting potential risks for patient treatment.
Area of Science:
- Microbiology
- Biochemistry
- Molecular Biology
Background:
- Clinical isolates of Escherichia coli can exhibit resistance to common antibiotics.
- Extended-spectrum beta-lactamases (ESBLs) are a significant cause of antibiotic resistance.
- Standard detection methods may fail to identify certain novel beta-lactamases.
Purpose of the Study:
- To characterize a novel beta-lactamase, TEM-125, found in a clinical Escherichia coli strain.
- To investigate the resistance mechanisms conferred by TEM-125 against beta-lactam antibiotics and inhibitors.
- To assess the detectability of TEM-125 using current clinical laboratory standards.
Main Methods:
- Phenotypic characterization of Escherichia coli TO799 resistance to penicillin-clavulanate and ceftazidime.
- Enzymatic assays to determine hydrolytic activity against ceftazidime.
- Determination of inhibitory concentration against clavulanate.
- Comparison with CLSI and French Society for Microbiology guidelines for ESBL detection.
Main Results:
- Escherichia coli TO799 displayed resistance to penicillin-clavulanate and ceftazidime.
- A novel beta-lactamase, TEM-125, was identified as the cause of this resistance.
- TEM-125 demonstrated hydrolytic activity against ceftazidime and high resistance to clavulanate.
- TEM-125 was not reliably detected by standard ESBL screening methods.
Conclusions:
- TEM-125 represents a complex mutant TEM beta-lactamase with significant hydrolytic and resistance properties.
- The difficulty in detecting TEM-125 underscores the emergence of challenging ESBL variants.
- There is a critical need to update and evaluate diagnostic methods to ensure accurate ESBL detection and prevent therapeutic failures.
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