lecture 7) persistant and chronic infections Flashcards
“if antibiotics and immune systems were 100% effective there would be no infections”. why isnt this the case in clinical practice?
persistant and chronic infections exist
why dont antibiotics kill all infections?
bacterial populations include persister cells, phenotypic variants
what is the main cause of antibiotics being unable to clear infections?
multidrug tolerance of persister cells
is there a genetic difference between bacterial cells and persister cells?
no
are persister cells mutants?
no because they dont grow in the presence of antibiotics
what makes normal bacterial cells different to persister cells if they are genetically the same?
persister cells arent growing
if persister cells are genetically identical to normal bacterial cells, what does this mean in terms of their phenotype?
they are phenotypic variants of the wild type
where in terms of growth phases are persister cells present?
mostly at the stationary phase
most persister cells are found at the stationary phase of growth. what does this suggest?
that optimal individual strategy is not to enter persistence
persister state is an alturistic behaviour benefiting the kin. what is meant by the term kin?
organism favours genetically related individuals over non-related organisms in social behaviours
if the whole bacterial population was killed by a lethal factor, what cells would remain and what would they do?
persister cells would remain
they would propagate genome with their kin
are these cells thinking??
are all cells equal?
no
when looking at individual cells you may have low/medium/high producers
when would evaluating if all cells are equal become problematic?
when looking at big cultures
if all cells in a bacterial population are genetically identical, how are persister cells produced?
by a stochastic process (random)
name the 2 process involved in mechanism of persistence
stochastic fluctuation
controlled and regulated mean of expression
