Related Experiment Video
Updated: May 20, 2026

05:18
High-Resolution Comparison of Bacterial Conjugation Frequencies
Published on: January 10, 2019
New perspectives into bacterial DNA transfer to human cells
Matxalen Llosa1, Gunnar Schröder, Christoph Dehio
1Departamento de Biología Molecular, Universidad de Cantabria-UC, and IBBTEC-UC-CSIC-SODERCAN, Santander, Spain.
Trends in Microbiology
|July 4, 2012
Summary
Bartonella henselae
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- The Type IV Secretion System (T4SS) in Bartonella henselae facilitates effector protein translocation into host cells.
- Recent studies highlight the T4SS's capability for macromolecular transfer, including DNA, into human cells.
Purpose of the Study:
- To explore the potential of Bartonella henselae's T4SS for novel DNA delivery into human cells.
- To discuss a new system for genetic modification using T4SS-mediated DNA delivery.
Main Methods:
- Investigating the T4SS VirB/D4 of Bartonella henselae.
- Analyzing DNA transfer mechanisms mediated by the bacterial secretion system.
- Evaluating DNA delivery via covalent attachment to site-specific integrase.
Main Results:
- Demonstrated the versatility of the T4SS for macromolecular substrate transfer, including DNA.
- Established the possibility of using this system for targeted DNA delivery into human cells.
Conclusions:
- The Bartonella henselae T4SS offers a versatile platform for DNA delivery into human cells.
- This system presents a novel approach for genetic modification, potentially complementing existing methods.
Related Concept Videos
Bacterial Transformation
In 1928, bacteriologist Frederick Griffith worked on a vaccine for pneumonia, which is caused by Streptococcus pneumoniae bacteria. Griffith studied two pneumonia strains in mice: one pathogenic and one non-pathogenic. Only the pathogenic strain killed host mice.
Griffith made an unexpected discovery when he killed the pathogenic strain and mixed its remains with the live, non-pathogenic strain. Not only did the mixture kill host mice, but it also contained living pathogenic bacteria that...
Griffith made an unexpected discovery when he killed the pathogenic strain and mixed its remains with the live, non-pathogenic strain. Not only did the mixture kill host mice, but it also contained living pathogenic bacteria that...
Bacterial Transformation
In 1928, bacteriologist Frederick Griffith worked on a vaccine for pneumonia, which is caused by Streptococcus pneumoniae bacteria. Griffith studied two pneumonia strains in mice: one pathogenic and one non-pathogenic. Only the pathogenic strain killed host mice.
Griffith made an unexpected discovery when he killed the pathogenic strain and mixed its remains with the live, non-pathogenic strain. Not only did the mixture kill host mice, but it also contained living pathogenic bacteria that...
Griffith made an unexpected discovery when he killed the pathogenic strain and mixed its remains with the live, non-pathogenic strain. Not only did the mixture kill host mice, but it also contained living pathogenic bacteria that...
Mechanism of Conjugation
Bacterial conjugation is a mechanism of horizontal gene transfer that enables the exchange of genetic material between bacterial cells through direct contact. This process is facilitated by a donor cell carrying a conjugative plasmid, which encodes genes necessary for pilus formation, DNA replication, and transfer. The conjugative plasmid plays a central role in initiating and executing the transfer of genetic material.The tra region of the conjugative plasmid encodes proteins responsible for...
Transduction
Among the three main modes of HGT—transformation, conjugation, and transduction—transduction is unique in that it is mediated by bacteriophages, or bacterial viruses.Transduction occurs in two ways. Generalized transduction occurs during the lytic cycle of a bacteriophage infection. In this process, bacteriophages infect bacterial cells, replicate within them, and ultimately cause cell lysis, releasing newly assembled virions. Occasionally, random fragments of the bacterial genome are...
Conjugation
Conjugation is a form of horizontal gene transfer that primarily occurs in bacteria and some archaea, promoting genetic diversity and adaptation. Bacteria can acquire resistance genes through conjugative plasmids, allowing them to survive antibiotic treatments that would otherwise be lethal. This process involves direct contact between cells through specialized structures such as the sex pilus and is mediated by conjugative plasmids, including the F (fertility) factor.Conjugation requires...
Transformation
Microbial communities are dynamic environments where cell lysis releases free DNA into the surroundings. Other cells can take up this extracellular DNA through a process known as transformation.When a cell incorporates this foreign DNA into its genome, resulting in genetic modification, the process is known as transformation. Cells capable of this process are termed competent. Competence can be natural, as observed in certain bacteria and archaea, or artificially induced in the...

