[CRISPR-Cas systems as weapons against pathogenic bacteria]

Abstract

CRISPR-Cas systems (Clustered Regularly Interspaced Short Palindromic Repeats) are the adaptive immune system of bacteria and archaea. They target foreign genetic elements thanks to small RNAs able to guide Cas nucleases to destroy them. These nucleases can be reprogrammed to target chromosomal sequences rather than invasive genetic elements. Whereas targeting the genome of eukaryotic cells enables the efficient genesis of mutations, DNA breaks induced by Cas nucleases are lethal in bacteria. This property can be used in the development of novel antimicrobial strategies. CRISPR-Cas systems can be delivered to target bacteria using bacteriophage capsids in order to specifically eliminate bacteria carrying antibiotic resistance genes or virulence factors. These technologies enable the development of novel tools based on CRISPR-Cas systems to specifically eliminate pathogenic bacteria and precisely modify the composition of various microbiomes.