Related Experiment Video
Updated: Oct 17, 2025
06:56
Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli
Published on: March 24, 2023
6.0K
IS1294 Reorganizes Plasmids in a Multidrug-Resistant Escherichia coli Strain
Yushan Pan1, Tengli Zhang1, Lijie Yu1
1College of Veterinary Medicine, Henan Agricultural Universitygrid.108266.b, Zhengzhou, China.
Microbiology Spectrum
|October 6, 2021
Summary
The insertion sequence IS1294 mediates the fusion of different plasmids, creating cointegrates that facilitate the spread of antibiotic resistance genes. This study reveals IS1294
Area of Science:
- Microbiology
- Genetics
- Molecular Biology
Background:
- Antibiotic resistance in Gram-negative bacteria is a growing concern, driven by genes like extended-spectrum β-lactamases (ESBLs) and 16S rRNA methylases.
- Plasmids are key vectors for the capture and horizontal gene transfer of antibiotic resistance genes, contributing to their emergence and spread.
- While insertion sequence IS26 is known to facilitate plasmid reorganization, the role of IS1294 in cointegrate formation remained unclear.
Purpose of the Study:
- To investigate the role of insertion sequence IS1294 in plasmid reorganization.
- To analyze the biological characteristics of cointegrates formed from different plasmids.
- To understand the mechanisms driving the formation of multidrug-resistant (MDR) cointegrate plasmids.
Main Methods:
- Plasmid genetic profiles were analyzed using conjugation, S1 nuclease pulsed-field gel electrophoresis (S1-PFGE), Southern hybridization, whole-genome sequencing (WGS), and PCR.
- Cointegrate traits were assessed through conjugation and stability assays.
- The impact of RecA knockout on plasmid reorganization frequency was evaluated.
Main Results:
- IS1294 mediated the fusion of conjugative and nonconjugative plasmids, forming cointegrates such as pC21-F1 and pC21-F4 at high frequencies.
- RecA knockout significantly reduced plasmid reorganization frequency by 100-fold, highlighting its role in the process.
- The coexistence of cointegrate pC21-F2 and its parent plasmids was observed for the first time.
- IS1294-mediated cointegration facilitated the cotransfer of blaCTX-M-55 and rmtB genes, promoting MDR dissemination.
Conclusions:
- IS1294 plays a significant role in the intermolecular recombination of plasmids with different replicons, leading to the formation of conjugative MDR cointegrates.
- This study provides novel insights into IS1294-driven cointegrate formation and its implications for the evolution and spread of multidrug resistance.
- Understanding these mechanisms is crucial for combating the dissemination of antibiotic resistance in bacterial populations.
Related Concept Videos
01:28Plasmids
329
Plasmids are extrachromosomal DNA molecules found in bacteria, archaea, and some eukaryotic microbes like yeast. These small, circular DNA structures typically contain fewer than 30 genes, although some may exist linearly. Plasmids vary in their number within a cell, known as copy number. Single-copy plasmids are present in one copy per cell and multi-copy plasmids are present in multiple copies, reaching over 100 copies per cell.Plasmids usually replicate independently of the chromosomal DNA...
329
01:23Stringent Response in E. coli
85
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
85
01:30Development of Antibiotic Resistance
489
Antibiotic resistance is a major public health concern that arises when bacteria evolve mechanisms to withstand the effects of antibiotic treatments. This resistance can be intrinsic, acquired through genetic mutations, or transferred between bacteria via horizontal gene transfer. The development of antibiotic resistance poses significant challenges in treating bacterial infections and necessitates ongoing research to develop new therapeutic strategies.Intrinsic resistance occurs when bacterial...
489