Speaker
Anne-Florence Bitbol
Description
Antimicrobial treatments select for resistance, and once resistance
becomes widespread, antimicrobials become useless. Resistance
evolution within a host can be strongly affected by variations of
antimicrobial concentration that may exist e.g. during a treatment. We
are investigating these effects using stochastic models. First, in a
microbial population of fixed size, we showed that fast alternations of
phases with and without antimicrobial strongly accelerate the evolution
of resistance, especially for large populations. Next, we considered
microbial populations of variable size, in which we studied the impact of
biocidal drugs, that kill microorganisms, and of biostatic drugs, that
prevent microorganisms from growing. In both cases, we showed that
the probability of treatment success, i.e. of extinction of the microbial
population, strongly depends on the period of the alternations of drug
absence and presence. Moreover, we showed that biocidal
antimicrobials promote resistance more than biostatic ones. Finally, we
found a population size-dependent critical drug concentration below
which antimicrobials cannot eradicate microbial populations.
Primary author
Anne-Florence Bitbol
