Lydia Robert Measuring the mutation rate of bacteria

An "arms race" in our bodies

A strange arms race is constantly underway in our bodies. It is a fight between our resistance to infectious diseases and the pathogens themselves. Mutations are the basis of this internal war, that allow pathogens to evolve. For example, they can enable them to develop greater resistance to antibiotics, or make them more virulent. Similarly, some cancer cells accumulate mutations that allow them to escape chemotherapy. However, environmental factors also induce mutations. For example, sublethal doses of antibiotics seem to promote mutagenesis in bacteria.

A pioneering new method

However, these results are controversial. Classic experiments have limitations and are prone to bias. Dr. Robert and her colleague Marina Elez have developed a groundbreaking method to overcome those hurdles. They use a single-cell approach to accurately characterize mutagenesis in Escherichia coli bacteria in different environments. They combine genetics, molecular biology, microfluidics, optogenetics, deep sequencing, mathematical modeling, statistics and other disciplines to achieve the best results.

The Foundation’s support

The support from Fondation Bettencourt Schueller will allow Dr. Robert to clear the obstacles of the traditional experimental approach. Her main goal is to define the environment’s impact on the bacterial mutation rate for the first time. She plans to study the effects of limiting the nutrients provided to the bacteria and adding sublethal doses of antibiotics. The idea is also to understand the impact of transient mutation rate variations on the evolution of bacteria, especially the emergence of resistance to antibiotics. In addition to being a key contribution to this field of research, the findings could have clinical implications as antibiotic resistance becomes a major health issue.