Clément Vulin

Clément Vulin photo

Project Title: 

Local nutrient exchanges to kickstart bacterial growth

Host Organisation: 

Swiss Federal Institute of Technology in Zürich (ETHZ)

Brief biography

Initially trained an agronomy engineer with a focus on molecular biology at AgroParisTech, I then followed an interdisciplinary master (AIV) in Paris, France and pursued my pHD in the Complex Matter and Systems laboratory under the supervision of Pascal Hersen. There, I developed new experimental tools to constrain and study the growth of yeast colonies. I was particularly focused on the effect of nutrient diffusion inside and outside a colony and how it can pair with cellular metabolism to drive colony growth.

I am generally interested in the role of populations of microbes on the microbes themselves, and on how a society of microbes self-organizes.

 I therefore moved to Switzerland in 2015 to join Martin Ackermann’s lab in ETH Zurich to study the role of bacterial groups in their exit from latency.

In my personal life, I enjoy every outdoor activity, especially when mountains are involved.

Short description of research project

This project studies the lag phase of single bacteria after their incubation in a non-favourable environment. Here, we test the hypothesis of metabolic exchanges between groups of cells due to phenotypic heterogeneity, which would favour their faster return to growth. After setting up the experimental methods, we developed a great collaboration to observe the single cell lag times of Staphylococcus aureus bacteria. S. aureus is known to cause recurrent and difficult to treat infections. These infections correlate with the observation of a heterogeneous colony size of plated samples. Our quantitative microscopy study of samples from patient, mice and pre-conditioned bacteria shoes that colony size heterogeneity is due to a wide range of single cell lag times. This corroborates macro sclase automated time-lapse observation on petri dishes. Our data suggests that longer lag phase of bacteria are induced, rather than selected byt the stringent incubation conditions (acidic media, starvation). This in turn allowas bacterial persistence through antibiotic challenges. Our study opens new ways to understand why some antibiotic treatments may fail even in the presence of non-resistent bacteria. Along with the lines of the proposed framework, further investigations will use the developed setups to study metabolic exchanges between cells returning to growth.