[SCAN] An evolutionary perspective on bacterial antibiotic resistance
Paulo Durão
| When |
16 Feb, 2022
from
12:00 pm to 01:00 pm |
|---|---|
| Contact Name | Rita Abranches |
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Title: An evolutionary perspective on bacterial antibiotic resistance
Speaker: Paulo Durão, alumni ITQB NOVA
Abstract: The emergence and dissemination of antibiotic resistance in bacterial populations depends on key evolutionary parameters, such as the rate at which bacteria acquire resistance, the selective pressures for and against resistant bacteria, and the rate and effects of mutations compensating for potential costs of resistance. Antibiotic resistance mutations typically occur in genes encoding essential functions and therefore these mutations are generally detrimental in the absence of drugs, the so-called, fitness cost of resistance. However, fitness costs strongly depend on the environment and bacteria can reduce fitness costs by acquiring additional mutations, known as compensatory mutations. During this presentation, I will demonstrate how these evolutionary parameters interplay with the environment by giving some examples. For instance, I will show how we have handled mice to show that the same antibiotic resistance mutation can have a wide despair of fitness effects strongly correlating with the microbiota composition of the host. Or how we have found that there is a significant effect of spatial structure (radial expansion) on the maintenance of streptomycin and rifampicin double resistances which is not observed for single resistances. We have also found that a strongly compensatory mutation in homogeneous conditions becomes deleterious under spatial structure conditions, suggesting that the nature of compensatory mutations under spatial structure is different.
