AUTHOR=Verbeke Frederick , De Craemer Severine , Debunne Nathan , Janssens Yorick , Wynendaele Evelien , Van de Wiele Christophe , De Spiegeleer Bart 

TITLE=Peptides as Quorum Sensing Molecules: Measurement Techniques and Obtained Levels In vitro and In vivo

JOURNAL=Frontiers in Neuroscience

VOLUME=11

YEAR=2017

URL=https://www.frontiersin.org/journals/neuroscience/articles/10.3389/fnins.2017.00183

DOI=10.3389/fnins.2017.00183

ISSN=1662-453X

ABSTRACT=<p>The expression of certain bacterial genes is regulated in a cell-density dependent way, a phenomenon called quorum sensing. Both Gram-negative and Gram-positive bacteria use this type of communication, though the signal molecules (auto-inducers) used by them differ between both groups: Gram-negative bacteria use predominantly <italic>N</italic>-acyl homoserine lacton (AHL) molecules (autoinducer-1, AI-1) while Gram-positive bacteria use mainly peptides (autoinducer peptides, AIP or quorum sensing peptides). These quorum sensing molecules are not only involved in the inter-microbial communication, but can also possibly cross-talk directly or indirectly with their host. This review summarizes the currently applied analytical approaches for quorum sensing identification and quantification with additionally summarizing the experimentally found <italic>in vivo</italic> concentrations of these molecules in humans.</p>