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Plasmid curing effect of trovafloxacin
1Laboratory of Genetics, Department of Biology MCA, University of Camerino, 62032, Camerino, Italy.
Abstract:
The effect of sub-inhibitory concentrations of trovafloxacin, a recently developed fluoroquinolone molecule, on the capability of Escherichia coli cells to maintain three different types of plasmids has been investigated by a number of approaches, including the quantification of the loss of plasmid-borne functions and of plasmid DNA by quantitative PCR. The results obtained demonstrate that at concentrations ranging from the MIC to 1/8 of the MIC, trovafloxacin induces a clear, albeit incomplete, 'episome-curing' effect which was observed with plasmids differing in copy number, size and nature of the replication origin of the episome. This effect was most likely not due to an alteration of DNA supercoiling.
Insights
Sub-inhibitory concentrations of trovafloxacin, a fluoroquinolone antibiotic, were found to cause plasmid loss in Escherichia coli. This "episome-curing" effect occurred across various plasmid types, suggesting a broad impact on bacterial genetics.
Area of Science:
- Microbiology
- Molecular Biology
- Pharmacology
Background:
- Fluoroquinolones are a class of synthetic broad-spectrum antibacterial drugs.
- Antibiotic resistance is a growing global health concern, often mediated by plasmids.
- Understanding how antibiotics affect plasmid stability is crucial for combating resistance.
Purpose of the Study:
- To investigate the impact of sub-inhibitory concentrations of trovafloxacin on plasmid maintenance in Escherichia coli.
- To determine if trovafloxacin can induce plasmid curing.
- To explore the characteristics of plasmids affected by trovafloxacin.
Main Methods:
- Quantitative PCR was used to measure plasmid DNA levels.
- Plasmid-borne functions were quantified to assess plasmid loss.
- Experiments were conducted using Escherichia coli with three different plasmid types.
Main Results:
- Trovafloxacin at sub-inhibitory concentrations (MIC to 1/8 MIC) induced a significant, though incomplete, episome-curing effect.
- This effect was observed across plasmids varying in copy number, size, and replication origin.
- The mechanism of curing was unlikely related to alterations in DNA supercoiling.
Conclusions:
- Sub-inhibitory concentrations of trovafloxacin can lead to the loss of plasmids in Escherichia coli.
- Trovafloxacin demonstrates a broad episome-curing capability, independent of specific plasmid features.
- Further research is needed to elucidate the precise mechanism of action and its implications for antibiotic resistance.