Vibrio cholerae Outer Membrane Vesicles Inhibit Bacteriophage Infection

Phages have been increasingly recognized for the significance of their interactions with bacterial cells in multiple environments. Bacteria use myriad strategies to defend against phage infection, including restriction modification, abortive infection, phase variation of cell surface receptors, phage-inducible chromosomal islands, and clustered regularly interspaced short palindromic repeat(s) (CRISPR)-Cas systems. The data presented here suggest that the apparently passive process of OMV release can also contribute to phage defense. By considering the effect of OMVs onV. cholerae infection by three unique virulent phages, ICP1, ICP2, and ICP3, we show that,in vitro , a reproducible reduction in bacterial killing is both dose and phage receptor dependent. This work supports a role for OMVs as natural decoys to defend bacteria from phage predation.