Different aspects of bacterial communication signals

Abstract

The communication or quorum-sensing signal molecules (QSSM) are specialized molecules used by numerous gram-negative bacterial pathogens of animals and plants to regulate or modulate bacterial virulence factor production. In plant-associated bacteria, genes encoding the production of these signal molecules, QSSMs, were discovered to be linked with the phenotype of bacterium, because mutation of these genes typically disrupts some behaviors of bacteria. There are other regulator genes which respond to the presence of signal molecule and regulate the production of signal molecule as well as some virulence factors. The synthesis and regulator genes (collectively called quorum-sensing genes hereafter) are repressed in low bacterial population but induced when bacteria reach to high cell density. Multiple regulatory components have been identified in the bacteria that are under control of quorum sensing. This review describes different communication signal molecules, and the various chemical, physical and genomic factors known to synthesize signals. Likewise, the role of some signal-degrading enzymes or compounds and the interaction of QSSMs with eukaryotic metabolism will be discussed here.

Heracleum orphanidis: chemical characterisation, and comparative evaluation of antioxidant and antimicrobial activities with specific interest in the influence on Pseudomonas aeruginosa PAO1

“…In addition, various plant Es differently affect the biofilm formation, so the method of preparation of Es should also be considered. 36,102 The results obtained for H. orphanidis suggested that AEs expressed low anti-biofilm activity compared to MEs and EEs, which was in conformity with the results obtained for antimicrobial activity. Es obtained from aerial parts were more effective than Es obtained from roots in the suppression of biofilm formation (Table 8).…”

“…QS signal molecules are the main participants of intercellular signaling pathway in which bacteria communicate and regulate gene expression by releasing small compounds called autoinducers into the environment when they reach a certain population density. Due to its role in regulatory processes and survival of bacteria, inhibition of QS systems by disrupting or interfering within these communications between bacterial cells, is an important target for developing novel anti-infective agents [34][35][36][37] . Some publications reported anti-QS activity of certain medicinal plants [38][39][40][41] .…”

“…Due to their role in regulatory processes and the survival of bacteria, inhibition of QS systems by disrupting or interfering within these communications between bacterial cells, is an important target for developing novel anti-infective agents. [33][34][35][36] Some publications reported the anti-QS activity of certain medicinal plants. [37][38][39][40] The aim of this study was to characterize the chemical composition of the EO and methanol Es of H. orphanidis.…”