Interbacterial competition and anti‐predatory behaviour of environmental Vibrio cholerae strains
Open Access
- 3 September 2020
- journal article
- research article
- Published by Wiley in Environmental Microbiology
- Vol. 22 (10), 4485-4504
- https://doi.org/10.1111/1462-2920.15224
Abstract
Vibrio cholerae isolates responsible for cholera pandemics represent only a small portion of the diverse strains belonging to this species. Indeed, most V. cholerae are encountered in aquatic environments. To better understand the emergence of pandemic lineages, it is crucial to discern what differentiates pandemic strains from their environmental relatives. Here, we studied the interaction of environmental V. cholerae with eukaryotic predators or competing bacteria and tested the contributions of the hemolysin and the type VI secretion system (T6SS) to those interactions. Both of these molecular weapons are constitutively active in environmental isolates but subject to tight regulation in the pandemic clade. We showed that several environmental isolates resist amoebal grazing and that this anti‐grazing defense relies on the strains’ T6SS and its actin‐cross‐linking domain (ACD)‐containing tip protein. Strains lacking the ACD were unable to defend themselves against grazing amoebae but maintained high levels of T6SS‐dependent interbacterial killing. We explored the latter phenotype through whole‐genome sequencing of fourteen isolates, which unveiled a wide array of novel T6SS effector and (orphan) immunity proteins. By combining these in silico predictions with experimental validations, we showed that highly similar but nonidentical immunity proteins were insufficient to provide cross‐immunity among those wild strains.Keywords
Funding Information
- H2020 European Research Council (724630)
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (310030_185022)
- Howard Hughes Medical Institute (55008726)
This publication has 117 references indexed in Scilit:
- A functional VipA-VipB interaction is required for the type VI secretion system activity of Vibrio cholerae O1 strain A1552BMC Microbiology, 2013
- Structure of a Peptidoglycan Amidase Effector Targeted to Gram-Negative Bacteria by the Type VI Secretion SystemCell Reports, 2012
- Type VI secretion requires a dynamic contractile phage tail-like structureNature, 2012
- Type VI secretion delivers bacteriolytic effectors to target cellsNature, 2011
- In vivo actin cross-linking induced by Vibrio cholerae type VI secretion system is associated with intestinal inflammationProceedings of the National Academy of Sciences of the United States of America, 2010
- A Type VI Secretion System of Pseudomonas aeruginosa Targets a Toxin to BacteriaCell Host & Microbe, 2010
- Bacterial competition: surviving and thriving in the microbial jungleNature Reviews Microbiology, 2009
- Comparative genomics reveals mechanism for short-term and long-term clonal transitions in pandemic Vibrio choleraeProceedings of the National Academy of Sciences of the United States of America, 2009
- Translocation of a Vibrio cholerae Type VI Secretion Effector Requires Bacterial Endocytosis by Host CellsCell Host & Microbe, 2009
- Type VI secretion system translocates a phage tail spike-like protein into target cells where it cross-links actinProceedings of the National Academy of Sciences of the United States of America, 2007