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

Autor(es)

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]

Afiliação do(s) autor(es)

^[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

• Tipo de documento: Artigo Científico
• Fonte: ENVIRONMENTAL MICROBIOLOGY; v. 22, n. 6 MAY 2020.
• Citações Web of Science: 0

Resumo

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)

• Processo FAPESP: 18/01388-6 - Homeostase de ferro em Chromobacterium violaceum: mecanismos regulatórios, sistemas de captação e papel em virulência
• Beneficiário: José Freire da Silva Neto
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 18/25445-9 - Bases genéticas da formação de biofilme em Chromobacterium violaceum
• Beneficiário: Juliana Alcoforado Diniz
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/50954-0 - Novos agentes terapêuticos obtidos de bactérias simbiontes de invertebrados brasileiros
• Beneficiário: Mônica Tallarico Pupo
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Temático
• Processo FAPESP: 15/26349-5 - Estudo químico e ecológico de microrganismos associados à simbiose Cecropia-Azteca
• Beneficiário: Taise Tomie Hebihara Fukuda
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto