This project aims to characterize the interaction of the major human pathogen, Vibrio cholerae, with phages and the role of quorum sensing in this process. To better understand the molecular principles underlying this interaction, we will combine biochemical, genetic, and microscopy approaches to pinpoint the factors driving phage-microbe interaction with an emphasis on the molecular mechanisms underlying these processes. In addition, we will harness the power of RNA-based microbial genetics to expose new mechanisms of phage defense. At the most general level, the proposed work will provide insights into phage-microbe interactions, quorum sensing, and the molecular principles underlying phage resistance. At a more specific level, the research will advance our understanding of phage replication processes and how phage infection is perceived and defended by the bacterial host. At a practical level, our research could expose new strategies for controlling phage infections, with possible applications in biotechnology and the food industry.