Cadmium ion inhibition of quorum signalling in Chromobacterium violaceum

Single-celled bacteria are capable of acting as a community by sensing and responding to population density via quorum signalling. Quorum signalling in Chromobacterium violaceum, mediated by the luxI/R homologue, cviI/R, regulates a variety of phenotypes including violacein pigmentation, virulence a...

Full description

Saved in:
Bibliographic Details
Published in:Microbiology (Society for General Microbiology) 2017-10, Vol.163 (10), p.1429-1435
Main Authors: Thornhill, Starla G, Kumar, Manish, Vega, Leticia M, McLean, Robert J C
Format: Article
Language:English
Subjects:
Biofilms
Cadmium - metabolism
Cadmium - pharmacology
Chitinases - biosynthesis
Chromobacterium - drug effects
Chromobacterium - growth & development
Chromobacterium - physiology
Gene Expression Regulation, Bacterial
Genes, Bacterial
Heavy Ions - adverse effects
Indoles - metabolism
Quorum Sensing - drug effects
Quorum Sensing - genetics
Transcription, Genetic
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Single-celled bacteria are capable of acting as a community by sensing and responding to population density via quorum signalling. Quorum signalling in Chromobacterium violaceum, mediated by the luxI/R homologue, cviI/R, regulates a variety of phenotypes including violacein pigmentation, virulence and biofilm formation. A number of biological and organic molecules have been described as quorum signalling inhibitors but, to date, metal-based inhibitors have not been widely tested. In this study, we show that quorum sensing is inhibited in C. violaceum in the presence of sub-lethal concentrations of cadmium salts. Notable Cd -inhibition was seen against pigmentation, motility, chitinase production and biofilm formation. Cd-inhibition of quorum-signalling genes occurred at the level of transcription. There was no direct inhibition of chitinase activity by Cd at the concentrations tested. Addition of the cognate quorum signals, N-hexanoyl homoserine lactone or N-decanoyl homoserine lactone, even at concentrations in excess of physiological levels, did not reverse the inhibition, suggesting that Cd-inhibition of quorum signaling is irreversible. This study represents the first description of heavy metal-based quorum inhibition in C. violaceum.
ISSN:1350-0872
1465-2080
DOI:10.1099/mic.0.000531