The expression of bacterial phenotype depends on the number of cells. That phenomenon is termed as quorum sensing. The quorum sensing is regulated by the freely diffusing, low molecular mass components. The Gram-negative bacteria utilize the derivatives of the homoserine lactones (acyl-HSL). The acyl-HSL are composed of homoserine lactone and fatty acids of different lengths. Acyl-HSL by binding regulatory proteins influence bioluminescence of Vibrio fisheri roods. In many cases the quorum sensing systems are multilevel, e.g. Pseudomonas aeruginosa (las, rhl, PQS - 2-heptyl-3-hydroxy-4-quinolone). The P. aeruginosa quorum sensing is responsible for the production of such pathogenic agents as toxins (exotoxin A), proteases (elastase, LasA protease and alkaline protease), polysaccharides and hemolysins (rhamnolipid and phospholipase). The listed pathogenic factors are responsible for complications in patients suffering from cystic fibrosis (CF). The features of fitopathogenic bacteria (Agrobacterium tumefaciens, Burkholderia cepacia, Ervinia carotovora) and biofilm formation are also regulated by acyl-HSL.
|Translated title of the contribution||Gram-negative bacteria cell to cell signalling systems and their importance in the expression of the phenotypic features|
|Number of pages||13|
|State||Published - 21 Sep 2005|
- Gram-negative bacteria
- Homoserine lactanes
- Quorum sensing