Related Experiment Video
Updated: Jul 24, 2026
06:10
Following Cell-fate in E. coli After Infection by Phage Lambda
Published on: October 14, 2011
Bacteriophage D: an IncD group plasmid-specific phage
Journal of General Microbiology
|December 1, 1985
Summary
Researchers confirmed plasmid incompatibility group D using compatibility experiments and isolated a specific phage, phage D. This phage targets IncD plasmid-encoded pili, aiding in the characterization of this plasmid group.
Area of Science:
- Microbiology
- Molecular Biology
- Virology
Background:
- Plasmid incompatibility groups are crucial for understanding plasmid maintenance and host range.
- Plasmid incompatibility group D (IncD) was previously tentatively identified.
Purpose of the Study:
- To reaffirm the existence of the IncD plasmid group.
- To further delineate the IncD plasmid group through phage isolation and characterization.
Main Methods:
- Compatibility experiments were performed on plasmids R687, R711b, R778b, and R840.
- A specific phage, designated phage D, was isolated.
- Phage adsorption and plaque formation assays were conducted on various bacterial strains carrying IncD plasmids.
- Phage morphology and nucleic acid content were analyzed.
Main Results:
- Compatibility experiments confirmed the IncD plasmid group.
- Phage D specifically adsorbed to pili encoded by IncD plasmids in Escherichia coli, Salmonella typhimurium, Proteus morganii, and Klebsiella oxytoca.
- Plaque formation was temperature-sensitive (26°C but not 37°C) and varied in morphology across different hosts.
- Phage D did not propagate on IncD plasmid-carrying strains of Providencia alcalifaciens, Providencia stuartii, or Serratia marcescens.
- Phage D is an RNA-containing phage with an isometric hexagonal outline, sensitive to chloroform, and adsorbs to IncD plasmid-coded pili.
Conclusions:
- The existence and delineation of the IncD plasmid incompatibility group were confirmed.
- Phage D serves as a specific marker for IncD plasmids and provides insights into their encoded pili structure and function.
More Related Videos
Related Concept Videos
01:30Lytic Cycle of Bacteriophages
Bacteriophages, also known as phages, are specialized viruses that infect bacteria. A key characteristic of phages is their distinctive “head-tail” morphology. A phage begins the infection process (i.e., lytic cycle) by attaching to the outside of a bacterial cell. Attachment is accomplished via proteins in the phage tail that bind to specific receptor proteins on the outer surface of the bacterium. The tail injects the phage’s DNA genome into the bacterial cytoplasm. In the lytic replication...
00:43Lysogenic Cycle of Bacteriophages
In contrast to the lytic cycle, phages infecting bacteria via the lysogenic cycle do not immediately kill their host cell. Instead, they combine their genome with the host genome, allowing the bacteria to replicate the phage DNA along with the bacterial genome. The incorporated copy of the phage genome is called the prophage. Some prophages can re-activate and enter the lytic cycle. This often occurs in response to a perturbation, such as DNA damage, but can also transpire in the absence of...
01:28Plasmids
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...
01:20Viral Replication: Lytic Cycle
Bacteriophages, or phages, are viruses that specifically infect bacteria. Among them, T-even bacteriophages, such as T4, exhibit a well-characterized lytic replication cycle in Escherichia coli (E. coli). This process ensures the rapid proliferation of the virus while ultimately leading to the destruction of the bacterial host.Attachment and DNA InjectionThe infection process begins with the recognition and binding of the T4 phage to the E. coli cell surface. Tail fibers of the phage...
01:26DNA Bacteriophages
Bacteriophages, or phages, are viruses that specifically infect bacteria, utilizing their genetic material to hijack host cellular machinery for replication. DNA bacteriophages employ single-stranded DNA (ssDNA) or double-stranded DNA (dsDNA) genomes. These phages exhibit diverse replication strategies and host interactions, influencing their ecological roles and applications in biotechnology and medicine.ssDNA BacteriophagesssDNA phages, with their small genomes, utilize unique strategies to...
01:23Bacteriophages of the Human Virome
Bacteriophages are found throughout the human body. They may even outnumber eukaryotic viruses, forming an important and dynamic component of the human virome. Indeed, phages represent the most abundant viral entities, with densities in the gut reaching up to 10⁹ particles per gram of fecal matter, and many belonging to orders such as Caudovirales and Microviridae, while a substantial proportion remains unclassified as viral “dark matter.”Lysogeny and Genetic ExchangeIn the gut, bacteriophages...