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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Interplay between two quorum sensing-regulated pathways, violacein biosynthesis and VacJ/Yrb, dictates outer membrane vesicle biogenesis in Chromobacterium violaceum

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Batista, Juliana H. [1] ; Leal, Fernanda C. [1] ; Fukuda, Taise T. H. [2] ; Alcoforado Diniz, Juliana [1] ; Almeida, Fausto [3] ; Pupo, Monica T. [2] ; da Silva Neto, Jose F. [1]
Total Authors: 7
[1] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Biol Celular & Mol Bioagentes Patogen, Ribeirao Preto, SP - Brazil
[2] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Dept Ciencias Farmaceut, Ribeirao Preto, SP - Brazil
[3] Univ Sao Paulo, Fac Med Ribeirao Preto, Dept Bioquim & Imunol, Ribeirao Preto, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Web of Science Citations: 0

Outer membrane vesicles (OMVs) are lipid nanoparticles released by Gram-negative bacteria, which play multiple roles in bacterial physiology and adaptation to diverse environments. In this work, we demonstrate that OMVs released by the environmental pathogen Chromobacterium violaceum deliver the antimicrobial compound violacein to competitor bacteria, mediating its toxicity in vivo at a long distance. OMVs purified by ultracentrifugation from the wild-type strain, but not from a violacein-abrogated mutant Delta vioABCDE, contained violacein and inhibited several Gram-positive bacteria. Competition tests using co-culture and transwell assays indicated that the C. violaceum wild-type strain killed Staphylococcus aureus better than the Delta vioABCDE mutant strain. We found that C. violaceum achieves growth phase-dependent OMV release by the concerted expression of two quorum sensing (QS)-regulated pathways, namely violacein biosynthesis and VacJ/Yrb system. Although both pathways were activated at high cell density in a QS-dependent manner, the effect on vesiculation was the opposite. While the Delta vioABCDE mutant produced twofold fewer vesicles than the wild-type strain, indicating that violacein induces OMV biogenesis for its own delivery, the Delta vacJ and Delta yrbE mutants were hypervesiculating strains. Our findings uncovered QS-regulated pathways involved in OMV biogenesis used by C. violaceum to package violacein into OMVs for interbacterial competition. (AU)

FAPESP's process: 18/01388-6 - Iron homeostasis in Chromobacterium violaceum: regulatory mechanisms, uptake systems and role in virulence
Grantee:José Freire da Silva Neto
Support Opportunities: Regular Research Grants
FAPESP's process: 18/25445-9 - Genetic basis of biofilm formation in Chromobacterium violaceum
Grantee:Juliana Alcoforado Diniz
Support Opportunities: Scholarships in Brazil - Post-Doctoral
FAPESP's process: 13/50954-0 - Novel therapeutic agents from the bacterial symbionts of Brazilian invertebrates
Grantee:Mônica Tallarico Pupo
Support Opportunities: BIOTA-FAPESP Program - Thematic Grants
FAPESP's process: 15/26349-5 - Chemical and ecological study of microorganisms associated with the symbiosis Cecropia-Azteca
Grantee:Taise Tomie Hebihara Fukuda
Support Opportunities: Scholarships in Brazil - Doctorate (Direct)