Quorum sensing relies upon the interaction of a diffusible signal molecule with a transcriptional activator protein to couple gene expression with cell population density. In Gram-negative bacteria, such signal molecules are usually N-acylhomoserine lactones (AHLs) which differ in the structure of their N-acyl side chains. Chromobacterium violaceum, a Gram-negative bacterium commonly found in s...

An ethyl acetate (EtOAc) extract isolated from the marine bacterium, Rheinheimera aquimaris QSI02, was found to exhibit anti-quorum sensing (anti-QS) activity. A subsequent bioassay-guided isolation protocol led to the detection of an active diketopiperazine factor, cyclo(Trp-Ser). Biosensor assay data showed that the minimum inhibitory concentration (MIC) of cyclo(Trp-Ser) ranged from 3.2 mg/m...

A methanol-soluble extract of the bark of Myristica cinnamomea was found to exhibit anti-quorum sensing activity, and subsequent bioassay-guided isolation led to the identification of the active compound malabaricone C (1). Compound 1 inhibited violacein production by Chromobacterium violaceum CV026 when grown in the presence of a cognate signaling molecule, N-3-oxohexanoyl-homoserine lactone. ...

Many members of the genus Chromobacterium produce violacein, a characteristic purple pigment which is induced by small diffusible N-acyl homoserine lactones (AHL) quorum-sensing molecules. In this study, the production of AHL of the non-pigmented C. aquaticum CC-SEYA-1(T) and the pigmented C. subtsugae PRAA4-1(T) were determined by using a CV026 biosensor assay. The profile of AHL was identifie...

Oxidized halogen antimicrobials, such as hypochlorous and hypobromous acids, have been used extensively for microbial control in industrial systems. Recent discoveries have shown that acylated homoserine lactone cell-to-cell signaling molecules are important for biofilm formation in Pseudomonas aeruginosa, suggesting that biofouling can be controlled by interfering with bacterial cell-to-cell c...

background and objectives: this study was designed to evaluate the activity of quercus infectoria galls extract (qifge) on virulence factor production and inhibition of quorum sensing (qs) in pseudomonas aeruginosa. materials and methods: minimum inhibitory concentration (mic) of qifge against 5 strains of p. aeruginosa was determined. the extract at sub-mic was used to determine biofilm format...

Chromobacterium pseudoviolaceum LMG 3953T was separated from Chromobacterium violaceum in 2009, but little is known of its origin or environmental role. Here, the genome of LMG 3953T was sequenced to understand the evolution of the genus Chromobacterium It is not clear from this sequence that C. pseudoviolaceum is taxonomically distinct from C. violaceum.

One obvious requirement for concerted action by a bacterial population is for an individual to be aware of and respond to the other individuals of the same species in order to form a response in unison. The term "quorum sensing" (QS) was coined to describe bacterial communication that is able to stimulate expression of a series of genes when the concentration of the signaling molecules has reac...

Strain PRAA4-1(T), a motile, Gram-negative, violet-pigmented bacterium, was isolated from Maryland forest soil and found to be orally toxic to Colorado potato beetle larvae and other insects. Morphological, biological, biochemical and molecular characterization revealed that this strain was most similar to Chromobacterium violaceum, the type species and only currently recognized member of the g...