Week 12: Evolutionary medicine Flashcards
Trade off
when antibiotic is absent, bacteria with resistant gene reproduces more slowly than the susceptible bacteria
Resistance Mutation
Random gene change produces a gene causing resistance
Natural selection for bacteria
when antibiotic is present, bacteria with resistance gene survive and reproduce
How does penicillin work?
Kills gram pos bacteria by damaging peptidoglycan in gram pos cell wall
Penicillin resistant bacteria
produces a protein that cuts penicillin molecules in half before they damage cell wall.
KPC gene
gives resistance to multiple antibiotics on a plasmid spread to many gram neg bacteria
Plasmids and resistance
- through gene modifications resistance genes end up on plasmids
- plasmids can be transferred to other bacteria via conjugation and transformation
Virulence
degree of damage caused by a pathogen to its host
High virulence
Results in:
-More pathogens being released
- an incapacitated host
Low virulence
Results in
-less pathogens released
- less incapacitated host
Virulence favors…
Pathogens that are:
High virulence and easier to infect host
Low virulence and difficult to infect host
Antiviral HIV treatment
HAART
Cancer
occurs after cells experience a mutation in genes that regulate mitosis and cell to cell attachment
Cancer cell needs
-divide without limit
-divide uncontrolled
-Metastasize (move elsewhere)
- Induce angiogenesis
Cancer characteristics
-Undifferentiated
-Usually have large nuclei
- Have multiple nuclei per cell
Local scale natural selection in cancer
- Mutations that favor reproduction and more mitosis.
Chemotherapy
chemotherapeutic agents kill susceptible cancer cells
Chemo resistance
- cancer cells have higher mutation rates then non cancer cells(= more random mutations)
- Resistance cancer cells left after chemo form new tumors
