Disrupting quorum sensing alters social interactions in Chromobacterium violaceum

Abstract

Quorum sensing (QS) is a communication system used by bacteria to coordinate a wide panel of biological functions in a cell density-dependent manner. The Gram-negative Chromobacterium violaceum has previously been shown to use an acyl-homoserine lactone (AHL)-based QS to regulate various behaviors, including the production of proteases, hydrogen cyanide, or antimicrobial compounds such as violacein. By using combined metabolomic and proteomic approaches, we demonstrated that QS modulates the production of antimicrobial and toxic compounds in C. violaceum ATCC 12472. We provided the first evidence of anisomycin antibiotic production by this strain as well as evidence of its regulation by QS and identified new AHLs produced by C. violaceum ATCC 12472. Furthermore, we demonstrated that targeting AHLs with lactonase leads to major QS disruption yielding significant molecular and phenotypic changes. These modifications resulted in drastic changes in social interactions between C. violaceum and a Gram-positive bacterium (Bacillus cereus), a yeast (Saccharomyces cerevisiae), immune cells (murine macrophages), and an animal model (planarian Schmidtea mediterranea). These results underscored that AHL-based QS plays a key role in the capacity of C. violaceum to interact with micro- and macroorganisms and that quorum quenching can affect microbial population dynamics beyond AHL-producing bacteria and Gram-negative bacteria.

Anti-Virulence Properties of Plant Species: Correlation between In Vitro Activity and Efficacy in a Murine Model of Bacterial Infection

“…On the other hand, the importance of the different virulence factors may lie in the ecological niche in which the bacteria develop. The main niche of C. violaceum is in swampy soils, where the production of violacein and other phenotypes regulated by QS allow it to compete for space and resources with other microorganisms [45], while according to our results in animal models, they are not determinants in establishment and damage.…”

“…It has a QS system called CviI/CviR, which consists of the CviI synthase and the cytoplasmic transcriptional regulator CviR [42]. This system regulates the synthesis of the pigment violacein and some virulence factors such as production of protease, chitinase, formation of biofilm, swarming [43], and the type VI secretion system [42,44,45]. Similarly, it has a T3SS located on the Cpi-1/-1a pathogenicity island, which is necessary for bacterial pathogenicity in a sepsis model in mice [46].…”

Quorum Sensing Inhibiting Activity of Cefoperazone and Its Metallic Derivatives on Pseudomonas aeruginosa

“…In this study, we evaluated the antiquorum sensing activities of CFP using C. violaceum ATCC 12472 reporter strain. C. violaceum ATCC 12472 produces several N-acyl-L-homoserine lactones (AHLs); Nnonanoyl-homoserine lactone, N-undecanoyl-homoserine lactone, N-(3-oxodecanoyl)-homoserine lactone (3-oxo-C10-HSL), N-(3-hydroxydecanoyl)-L-homoserine lactone, N-(3hydroxyundecanoyl)-homoserine lactone, and 3-oxo-C12-HSL (Mion et al, 2021). N-(3-hydroxydecanoyl)-L-homoserine lactone is the main inducer that controls violacein production via quorum sensing.…”

Quorum Sensing Regulates the Hydrolytic Enzyme Production and Community Composition of Heterotrophic Bacteria in Coastal Waters

“…Interestingly, in our study, the effect of AHL treatment on the BCC seemed to mirror the effect on specific enzymatic activities, as suggested by the Procrustes analysis, which supports this hypothesis. Second, QS-regulated mechanisms could impact microbial communities through the production of antimicrobial compounds that kill or inhibit the growth of microorganisms (including antibiotics or algaecides), which has previously been documented in aquatic strains (Rolland et al, 2016;Mion et al, 2021). Finally, it is possible that AHL-driven changes in BCC resulted from the additional functions of AHLs (or their degradation products), which include antibacterial activity and iron chelation properties (Kaufmann et al, 2005;Schertzer et al, 2009).…”