Prof Melanie Blokesch
Associate Professor at the Laboratory of Molecular Microbiology, EPFL
- Pathoecology of the human pathogen Vibrio cholerae
- Horizontal gene transfer in Gram-negative bacteria
FEMS Expert: Prof Melanie Blokesch
Prof Melanie Blokesch’s research focuses on how bacteria evolve in natural environments to emerge as human pathogens and how horizontal gene transfer (HGT) contributes to pathogen emergence. The model organism for these studies is the causative agent of cholera, Vibrio cholerae.
Her research group’s recent work deciphered new aspects of the regulatory network that governs natural competence for transformation in this organism, which is a widespread mode of HGT in bacteria. Moreover, cell microbiology-based studies by Melanie’s group provided important insights into the mechanistic aspects of the DNA-uptake machinery and the DNA absorption process in V. cholerae. In addition, they also investigate a molecular killing device known as the type VI secretion system (T6SS) in diverse species of the genus Vibrio. This system is activated in pandemic V. cholerae strains upon their growth on chitinous surfaces.
Chitin is the most abundant polysaccharide in marine environments and used by V. cholerae and other chitinolytic bacteria as a major carbon source. Chitin-induced activation of the T6SS leads to the killing of neighboring bacteria followed by the absorption of the prey-released DNA. They therefore speculated that the T6SS serves for DNA acquisition in naturally competent bacteria and that it fosters horizontal gene transfer and, consequently, evolution.
Melanie’s research group also investigates the role of (minor) virulence and colonization factors in the environmental lifestyle of the pathogen with a primary focus on the interaction of V. cholerae and grazing amoebae.
Since 2017, Melanie is a Howard Hughes Medical Institute (HHMI) International Research Scholar.