DNA Transfer Between Micrbobes Flashcards
What are the properties of bacterial genome
Typically a singular circular chromosome
No nuclear membrane - defined region called nucleotide
Plasmids - other small circular self replicating DNA molecules found in cytoskeleton
What is horizontal and vertical gene transfer
Horizontal gene transfer is directly from one organism to another
Vertical gene transfer is from parent to offspring
What genes can bacteria transfer horizontally
Genes affecting virulence and drug resistance
What are two important attributes transferred horizontally by bacteria
Virulence factors
Antibiotic resistance
What are virulence factors
Attributes that help bacteria survive in the host, sometimes at the hosts expense
What is antibiotic resistance
Attributes that reduce the effectiveness of antibiotics against the targeted bacteria.
What are the 3 types of horizontal gene transfer in bacteria
Transformation
Transduction
Conjugation
Outline horizontal gene transfer Transformation
Simplest method
Transformation involved uptake of short fragments of naked DNA by naturally transformable bacteria.
What is conjugation horizontal gene transfer
Conjugation involved transfer of DNA material via sexual pilus (long type of fimbri) and requires cell to cell contact
What is transduction horizontal gene transfer
Transduction involved transfer of DNA from one bacterium into another via bacteriophages. Only infects highly specific types of bacteria
What dictates which bacteria bacteriophages bind to
Interactions between surface receptors, and ligands at the base plate of bacteriophages.
Where does bacteriophage replication occur, outline the requirements for the genetic material it carries
Replication occurs within host cells cytoplasm. Many are made in each cell. Cell destroyed upon exit, hence cell death.
Sometime virus packages bacteria plasmid instead of original viral genetic material. Bacteriophages work regardless of type of genetic material in capsid.
What is phage therapy
The therapeutic use of bacteriophages to treat pathogenic bacterial infections
What are the advantages of bacteriophage therapy
Very specific
Replicate at the site of infection
Occur naturally
Safe
Active against antibiotic resistant bacteria
What are the disadvantages of bacteriophage therapy
Additional research required
Development of phage resistance and phage neutralising antibodies
Not accessible to intracellular pathogens
Difficult to administer
Can transfer toxin genes between bacteria
