Related Experiment Video

Updated: Feb 2, 2026

Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli
06:56

Detection of Horizontal Gene Transfer Mediated by Natural Conjugative Plasmids in E. coli

Published on: March 24, 2023

7.0K

pBuzz: A cryptic rolling-circle plasmid from a commensal Escherichia coli has two inversely oriented oriTs and is

Robert A Moran1, Ruth M Hall1

  • 1School of Life and Environmental Sciences, The University of Sydney, NSW, Australia.

Plasmid
|November 24, 2018
PubMed

Insights

This study details how antibiotic resistance genes on a large plasmid (p838B-R) were transferred with a smaller plasmid (pBuzz) in E. coli. This plasmid mobilization explains the spread of antimicrobial resistance.

Area of Science:

  • Microbiology
  • Genetics
  • Molecular Biology

Background:

  • Commensal E. coli can harbor multiple plasmids, contributing to antibiotic resistance.
  • Plasmid p838B-R, a B/O plasmid, carries resistance genes for ampicillin, streptomycin, and sulphamethoxazole.
  • The transfer of antibiotic resistance genes is a significant public health concern.

Purpose of the Study:

  • To characterize the plasmids involved in the transfer of antibiotic resistance.
  • To determine the complete sequences of the conjugative plasmid p838B-R and the mobilised plasmid pBuzz.
  • To elucidate the mechanism of co-transfer between p838B-R and pBuzz.

Main Methods:

  • Plasmid DNA extraction and sequencing.
  • Conjugation experiments to assess gene transfer.
  • Bioinformatic analysis of plasmid sequences and comparison with known plasmids.

Main Results:

  • The 94,803 bp plasmid p838B-R contains an 8400 bp resistance island with blaTEM, strA, and sul2 genes.
  • The 1982 bp plasmid pBuzz was mobilized by p838B-R with 70% efficiency.
  • pBuzz possesses oriT-like sites enabling relaxase-in-trans mobilization by p838B-R's relaxase and accessory proteins.
  • Related rolling-circle plasmids with diverse oriTs were identified in the GenBank database.

Conclusions:

  • p838B-R is a conjugative plasmid capable of mobilizing other plasmids like pBuzz.
  • The identified oriT-like sequences in pBuzz facilitate its co-transfer via relaxase-in-trans mobilization.
  • The findings provide insights into the mechanisms of antibiotic resistance gene dissemination via plasmids.
Keywords:
I-complex plasmidsMobilisationRelaxase-in transRolling-circle plasmidsoriT

More Related Videos

Transformation of Plasmid DNA into E. coli Using the Heat Shock Method07:46

Transformation of Plasmid DNA into E. coli Using the Heat Shock Method

Published on: August 1, 2007

72.1K
Use of In Vivo Assembly for High-efficiency Plasmid Construction06:25

Use of In Vivo Assembly for High-efficiency Plasmid Construction

Published on: February 7, 2025

1.5K

Related Concept Videos

Plasmids01:28

Plasmids

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...
1.7K
Circles01:18

Circles

A circle in the coordinate plane is defined as the set of all points that lie at a constant distance, known as the radius, from a fixed point called the center. This relationship is captured using the distance formula. For a point (x, y) on the circle and a center (h, k), the distance between them equals the radius r. By squaring both sides of the distance formula, the equation of the circle is written in standard form:Constructing the Equation from Geometric InformationIf the center and the...
242
Rolling Without Slipping01:09

Rolling Without Slipping

People have observed the rolling motion without slipping ever since the invention of the wheel. For example, one can look at the interaction between a car's tires and the surface of the road. If the driver presses the accelerator to the floor so that the tires spin without the car moving forward, there must be kinetic friction between the wheels and the road's surface. If the driver slowly presses the accelerator, causing the car to move forward, the tires roll without slipping. It is...
5.3K
Rolling With Slipping01:14

Rolling With Slipping

Rolling with slipping is a physical phenomenon that occurs when a rolling object experiences both rotational and linear motion but also experiences frictional forces that cause slipping. This phenomenon can occur in various situations, such as when a tire rolls on a wet road or a ball rolls on a rough surface.
An object's rolling motion is characterized by its rotation around its axis, while linear motion refers to the object's translational motion along a surface. Frictional forces can...
7.9K
Rolling Resistance01:21

Rolling Resistance

When a solid cylinder rolls steadily on a rigid surface, the normal force applied by the surface on the cylinder is perpendicular to the tangent at the contact point. However, since no materials are entirely rigid, the surface's reaction to the cylinder involves a range of normal pressures.
For instance, imagine a hard cylinder rolling on a comparatively soft surface. The cylinder's weight compresses the surface beneath it. As the cylinder moves, the material in front of it slows down due to...
662
Inverse Trigonometric Functions01:29

Inverse Trigonometric Functions

Inverse trigonometric functions are fundamental mathematical tools that reverse the actions of standard trigonometric functions. While trigonometric functions map angles to ratios, inverse trigonometric functions perform the opposite operation by mapping a ratio back to its corresponding angle. These functions are essential in various applications, particularly in determining angles when given specific distances, such as calculating elevation angles in navigation and engineering.For a function...
275