CRISPR tools to study and fight pathogenic bacteria

Abstract
Over the past few years CRISPR systems have been derived into powerful tools to edit genomes, control gene expression, visualize nucleic acids in vivo, modify epigenetic marks, kill cells and more. Most of these tools rely on the RNA-guided nuclease known as Cas9 which can be easily reprogrammed to bind and cut almost any position in a genome. We focus on the application of these technologies to Bacteria. We have recently investigated the properties of Cas9 as well as the catalytic dead variant known as dCas9 in E. coli. The introduction of double strand breaks by Cas9 at a specific genomic position leads to cell death as such beaks cannot be repaired through homologous recombination, the main DNA repair pathway in bacteria. We used this property as a selection tool in both E. coli and S. pneumoniae, and to develop sequence-specific antimicrobials against S. aureus. Work on the dCas9 protein has revealed how it can be used to precisely tune the expression level of several target genes independently and with low noise levels. Finally, the ability to knockdown gene expression with dCas9 can also be used in high-throughput screens to unravel gene function and interaction. All in all, CRISPR provide a fantastic toolkit to study and fight pathogenic bacteria.

 

Biosketch
Dr. Bikard obtained a Engineer degree from AgroParisTech, France, as well as a MS degree and PhD from Paris Diderot University for his work performed at the Institut Pasteur on the integron bacterial recombination system. He then joined the laboratory of Luciano Marraffini at the Rockefeller University as a postdoctoral fellow where he received the Harvey L. Karp award to work on CRISPR-Cas systems.  Currently, David is a head of lab at the Institut Pasteur in the department of Microbiology where he started his group in 2014. David is interested in applying engineering principles to better understand and fight pathogenic bacteria. His work on the interplay between DNA repair pathways and CRISPR-Cas systems  is supported by an ERC starting grant. Recently, David received the Pasteur-Vallery Radot award. He is also a co-founder of Eligo Bioscience.