Related Experiment Video
Updated: May 5, 2026
07:59
Investigating Flagella-Driven Motility in Escherichia coli by Applying Three Established Techniques in a Series
Published on: May 10, 2020
7.6K
A novel linear plasmid mediates flagellar variation in Salmonella Typhi
Stephen Baker1, Jonathan Hardy, Kenneth E Sanderson
1The Wellcome Trust Sanger Institute, Hinxton, Cambridgeshire, United Kingdom. sgb@sanger.ac.uk
Plos Pathogens
|May 16, 2007
Summary
Salmonella Typhi strains in Indonesia can possess a unique linear plasmid, pBSSB1, encoding an additional flagellin antigen (H:z66). This discovery expands our understanding of Salmonella Typhi genetics and antigen variation.
Area of Science:
- Microbiology
- Genetics
- Molecular Biology
Background:
- Salmonella enterica serovar Typhi (S. Typhi) is the causative agent of typhoid fever.
- Unlike most Salmonella serovars, S. Typhi is typically monophasic, possessing only the phase 1 flagellin gene (fliC) encoding the H:d antigen.
Purpose of the Study:
- To investigate the genetic basis of the H:z66 flagellin antigen expression in specific S. Typhi strains.
- To characterize the novel genetic element responsible for H:z66 antigen production.
Main Methods:
- Molecular analysis of H:z66 positive S. Typhi strains.
- DNA sequencing of the identified plasmid.
- Bioinformatic prediction of coding sequences on the plasmid.
Main Results:
- A novel linear plasmid, named pBSSB1, was identified in H:z66+ S. Typhi strains.
- The H:z66 flagellin structural gene (fljB(z66)) is located on pBSSB1.
- pBSSB1 is approximately 27 kbp and predicted to contain 33 coding sequences.
- pBSSB1 represents the first described non-bacteriophage-related linear plasmid in Enterobacteriaceae.
Conclusions:
- The H:z66 antigen in S. Typhi is encoded by a gene on a unique linear plasmid, pBSSB1.
- pBSSB1 is a novel genetic element within the Enterobacteriaceae family.
- This finding contributes to the understanding of genetic diversity and antigen expression in S. Typhi.
Related Concept Videos
01:29Cytoskeletal Proteins in Bacteria
3.5K
Bacterial cells were initially considered simple, randomly organized structures lacking a cytoskeleton. However, the discovery of cytoskeleton homologs in bacteria led to the change of this opinion. Bacterial cytoskeletal filaments regulate the cell shape, cell polarity, cell division, and partitioning of plasmids during cell division. It was later discovered that bacterial cytoskeletal proteins, mainly actin and tubulin homologs, are diverse compared to their eukaryotic counterparts. On the...
3.5K
01:18Flagella and Motility in Bacteria
5.4K
Flagella are specialized, thread-like structures that extend from a bacteria's cell envelope. They play a crucial role in motility and chemotaxis. Their structural organization and functioning exemplify sophisticated biological engineering, enabling bacterial survival and adaptability in diverse environments.Structure of the FlagellumA bacterial flagellum consists of three key components: the filament, the hook, and basal body. The filament, a long, helical structure composed of repeating...
5.4K
01:28Fimbriae, Pili, and Axial Filaments
3.3K
Fimbriae and pili are specialized bacterial surface structures that play pivotal roles in adhesion, genetic exchange, and motility. Composed primarily of pilin protein, these hairlike appendages are crucial for bacterial survival and pathogenicity in various environments.Fimbriae: Adhesion and PathogenicityFimbriae are fine, filamentous structures measuring 2–10 nanometers in diameter and are densely distributed on the bacterial cell surface. They facilitate bacterial adhesion to abiotic...
3.3K
01:28Plasmids
4.2K
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...
4.2K
01:19Conjugation
3.0K
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...
3.0K
01:19Mechanism of Conjugation
1.6K
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...
1.6K