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Updated: Feb 11, 2026
08:06
The Use of a β-lactamase-based Conductimetric Biosensor Assay to Detect Biomolecular Interactions
Published on: February 1, 2018
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Plasmids carrying DHA-1 β-lactamases
Claire Hennequin1,2, Viviane Ravet3, Frédéric Robin4,5,6
1Université Clermont Auvergne, CNRS, Laboratoire Microorganismes: Génome et Environnement, Clermont-Ferrand, France. claire.hennequin@uca.fr.
Summary
Plasmids carrying the DHA-1 cephalosporinase gene are spreading globally in bacteria like Klebsiella pneumoniae. These plasmids often harbor multiple antibiotic resistance genes, contributing to multidrug resistance.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- The DHA-1 cephalosporinase is a significant beta-lactamase conferring antibiotic resistance.
- Plasmids mediating DHA-1 cephalosporinase have been identified globally, originating from Salmonella sp. in the 1990s.
- These resistance determinants are primarily found in Klebsiella pneumoniae but also in other bacterial species.
Purpose of the Study:
- To provide an updated review of plasmids mediating DHA-1 cephalosporinase.
- To highlight the global dissemination and characteristics of these resistance plasmids.
- To detail the genetic makeup and mobility of DHA-1 carrying plasmids.
Main Methods:
- Literature review of studies reporting DHA-1 cephalosporinase plasmids.
- Analysis of plasmid characteristics including size, incompatibility groups, and transferability.
- Examination of the genetic context and co-expressed resistance genes.
Main Results:
- DHA-1 cephalosporinase plasmids are found worldwide, predominantly in Klebsiella pneumoniae.
- These plasmids exhibit considerable diversity in size (22-313 kb) and incompatibility groups (e.g., R, L/M, FII(k)).
- The blaDHA-1 gene is frequently co-expressed with a wide array of other antibiotic resistance genes, forming a mosaic multidrug resistance region.
Conclusions:
- Plasmids carrying DHA-1 cephalosporinase represent a significant challenge due to their global spread and association with multidrug resistance.
- The genetic plasticity and mosaic structure of these plasmids facilitate the dissemination of various antibiotic resistance genes.
- Continued surveillance and characterization of DHA-1 mediating plasmids are crucial for combating antimicrobial resistance.
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