OBJECTIVES Quorum-sensing systems regulate expression of several virulence factors and may affect the MexAB-OprM efflux system in Pseudomonas aeruginosa. This study investigated the relationship between two quorum-sensing systems, efflux pump MexAB-OprM expression and antimicrobial resistance in 33 clinical isolates of P. aeruginosa. METHODS Expression of the quorum-sensing regulatory genes l...

We investigate issues related to the probe complexity of the And-Or quorum system and its implementation in a dynamic environment. Our contribution is twofold: We first analyze the algorithmic probe complexity of the And-Or quorum system, and present two optimal algorithms. The first is a non-adaptive algorithm with O( √ n log n) probe complexity, which matches a known lower bound. The second i...

Quorum systems serve as a basic tool providing a uniform and reliable way to achieve coordination in a distributed system. They are useful for distributed and replicated databases, name servers, mutual exclusion, and distributed access control and signatures. Traditionally, two basic methods have been used to evaluate quorum systems: the analytical approach, and simulation. This paper proposes ...

We studied the inoculum size effect in Ceratocystis ulmi, the dimorphic fungus that causes Dutch elm disease. In a defined glucose-proline-salts medium, cells develop as budding yeasts when inoculated at > or = 10(6) spores per ml and as mycelia when inoculated at <10(6) spores per ml. The inoculum size effect was not influenced by inoculum spore type, age of the spores, temperature, pH, oxygen...

Abstract Background Bacterial cells communicate via small extracellular molecules that facilitate gene expression which is dependent on cell density and this mechanism known as Quorum Sensing (QS). At low density, these bacteria show a single cellular type of behavior but once they reach the threshold level alter to multicellular hence QS established by transfer signalling called autoinducers. ...

Here, we present the draft genome sequence of Aeromonas caviae strain L12, which shows quorum-sensing activity. The availability of this genome sequence is important to the research of the quorum-sensing regulatory system in this isolate.

The virulence and resistance of pathogenic microorganisms are promoted by quorum-sensing (QS) mediated traits biofilms. development antimicrobial agents which can reduce the incidence microbial disrupting establishment biofilms QS, constitute a suitable strategy to emergence strains that resistant antibiotics. In this study, 3-(1,3-dithian-2-ylidene) pentane-2,4-dione ( 1 ) ethyl-2-cyano-2-(1,3...

Signaling among rhizobacteria and other soil microorganisms is an important mechanism to ensure a successful symbiotic relationship with their phytobionts. Quorum-sensing involves signaling molecules that provide essential networks for communication in the rhizosphere. These relay inter-and-intra-species information coordinates controls behavior mixed communities, expression of these changes re...

Quorum sensing is a system of stimuli and responses in relation to bacterial cell population density that regulates gene expression, including virulence determinants. Consequently, quorum sensing has been an attractive target for the development of novel anti-infective measures that do not rely on the use of antibiotics. Anti-quorum sensing has been a promising strategy to combat bacterial infe...

Quorum sensing is a bacterial mechanism used to synchronize the coordinated response of a microbial population. Because quorum sensing in Gram-negative bacteria depends on release and detection of a diffusible signaling molecule (autoinducer) among a multicellular group, it is considered a simple form of cell-cell communication for the purposes of mathematical analysis. Stochastic equation syst...