The role of quorum sensing in Escherichia coli (ETEC) virulence factors.

Authors :: Sturbelle RT
de Avila LF
Roos TB
Borchardt JL
da Conceição Rde C
Dellagostin OA
Leite FP
Source :: Veterinary microbiology [Vet Microbiol] 2015 Nov 18; Vol. 180 (3-4), pp. 245-52. Date of Electronic Publication: 2015 Aug 21.
Publication Year :: 2015
Abstract: Quorum sensing (QS) is a signaling system among bacteria mediated by auto-inducer substances (AI). Whenever the concentration of these molecules reaches a threshold corresponding to a high cell density or quorum, the whole population starts a coordinated expression of specific genes. Studies have shown that epinephrine is also responsible for activating specific bacterial genes. This work aimed to investigate the role of conditioned medium (containing AI), epinephrine and their association on growth, motility, F4 fimbriae and heat-labile toxin (LT) expression on enterotoxigenic Escherichia coli (ETEC, E68). A significant increase in motility, F4 and LT expression, was observed in the ETEC culture supplemented with conditioned medium and epinephrine. These findings suggest that ETEC uses some components of conditioned medium (e.g., AI molecules), host molecules (epinephrine), and their association to modulate the expression of important virulence genes.<br /> (Copyright © 2015 Elsevier B.V. All rights reserved.)