Established Microbial Colonies Can Survive Type VI Secretion Assault.

TitleEstablished Microbial Colonies Can Survive Type VI Secretion Assault.
Publication TypeJournal Article
Year of Publication2015
AuthorsBorenstein, DBruce, Ringel, P, Basler, M, Wingreen, NS
JournalPLoS Comput Biol
Date Published2015 Oct
KeywordsCell Communication, Cell Survival, Computer Simulation, Escherichia coli, Microbiota, Models, Biological, Type VI Secretion Systems, Vibrio cholerae

<p>Type VI secretion (T6S) is a cell-to-cell injection system that can be used as a microbial weapon. T6S kills vulnerable cells, and is present in close to 25% of sequenced Gram-negative bacteria. To examine the ecological role of T6S among bacteria, we competed self-immune T6S+ cells and T6S-sensitive cells in simulated range expansions. As killing takes place only at the interface between sensitive and T6S+ strains, while growth takes place everywhere, sufficiently large domains of sensitive cells can achieve net growth in the face of attack. Indeed T6S-sensitive cells can often outgrow their T6S+ competitors. We validated these findings through in vivo competition experiments between T6S+ Vibrio cholerae and T6S-sensitive Escherichia coli. We found that E. coli can survive and even dominate so long as they have an adequate opportunity to form microcolonies at the outset of the competition. Finally, in simulated competitions between two equivalent and mutually sensitive T6S+ strains, the more numerous strain has an advantage that increases with the T6S attack rate. We conclude that sufficiently large domains of T6S-sensitive individuals can survive attack and potentially outcompete self-immune T6S+ bacteria.</p>

Alternate JournalPLoS Comput Biol
PubMed ID26485125
PubMed Central IDPMC4619000