Quorum-sensing- and type VI secretion-mediated spatiotemporal cell death drives genetic diversity in Vibrio cholerae.

Publication Year
2022

Type

Journal Article
Abstract

Bacterial colonies composed of genetically identical individuals can diversify to yield variant cells with distinct genotypes. Variant outgrowth manifests as sectors. Here, we show that Type VI secretion system (T6SS)-driven cell death in Vibrio cholerae colonies imposes a selective pressure for the emergence of variant strains that can evade T6SS-mediated killing. T6SS-mediated cell death occurs in two distinct spatiotemporal phases, and each phase is driven by a particular T6SS toxin. The first phase is regulated by quorum sensing and drives sectoring. The second phase does not require the T6SS-injection machinery. Variant V. cholerae strains isolated from colony sectors encode mutated quorum-sensing components that confer growth advantages by suppressing T6SS-killing activity while simultaneously boosting T6SS-killing defenses. Our findings show that the T6SS can eliminate sibling cells, suggesting a role in intra-specific antagonism. We propose that quorum-sensing-controlled T6SS-driven killing promotes V. cholerae genetic diversity, including in natural habitats and during disease.

Journal
Cell
Volume
185
Issue
21
Pages
3966-3979.e13
Date Published
2022 Oct 13
ISSN Number
1097-4172
Alternate Journal
Cell
PMCID
PMC9623500
PMID
36167071