Chemical Communication-Do We Have a Quorum?

Abstract

There are two types of bacterial communication systems, those in which the signal produced by bacteria is directed only at other organisms, and those where the signal is detected by others and self. The latter is involved in adaptation to the environment. The adaptation signals are autoinducers, the response is population density-dependent and has been termed "quorum sensing". Our current knowledge of bacterial signaling systems indicates that Gram positive bacteria use small peptides for both types of signaling, whereas Gram negative organisms use homoserine lactones as autoinducers. Gram- negative bacteria internalize the signals which act upon an intracellular receptor. Gram-positive bacteria use the signals as ligands for an extracellular receptor of a two-component signaling system. Inhibitors of quorum sensing compounds for both Gram positive and Gram negative bacteria are being explored. Signal inhibitors could be potentially effective in impeding biofilm formation, which might prolong the utility of the currently available antibiotics in this era of antibiotic resistance. In this review, we will explore both bacteria-host and bacteria-bacteria communication systems, with an emphasis on inhibitors of these systems both natural and synthetic.

Probiotic bacteria change Escherichia coli-induced gene expression in cultured colonocytes: Implications in intestinal pathophysiology

“…Chemical signals produced and detected by bacteria can be directed at other bacteria and self. This phenomenon, called as quorum sensing, is important for the microorganism's adaptation to the local environment [53] . This fundamental prokaryotic behavior (among bacteria) is known to affect the symbiotic or antagonistic environment created within the gut milieu.…”

Strategies for culture of ‘unculturable’ bacteria

“…Another key feature of biofilm communities is bacterial communication through networks of signals (Davey, 2008). These include quorum‐sensing mechanisms that are involved in the regulation of the bacterial community structure, properties and survival (De Kievit et al , 2001; Konaklieva & Plotkin, 2006; ten Cate, 2006).…”

“…Another key feature of biofilm communities is bacterial communication through networks of signals (Davey, 2008). These include quorum-sensing mechanisms that are involved in the regulation of the bacterial community structure, properties and survival (De Kievit et al, 2001;Konaklieva & Plotkin, 2006;ten Cate, 2006). Some bacterial growth factors have been considered analagous to mammalian cytokines -circulating regulatory molecules that mediate cellular communication.…”

Gas Chromathography as a Tool in Quorum Sensing Studies

“…The no volatile compounds with QSI properties, like some flavonoids, malyngamide (Kwan et al, 2010), S-ribosyl-Lhomocysteine analogs (Shen et al, 2006) and macromolecules (Amara et al, 2011), are not revised. For a general revision Chan et al, 2004;Dobrestov et al, 2009;Konaklieva & Plotkin, 2006;McDougald et al, 2007;Ni et al, 2009, Rasmussen et al, 2006 and the issue number 1 of 111 th volume of The Chemical Reviews are suggested.…”