title: Bacteria hold their breath upon surface contact as shown in a strain of Escherichia coli, using dispersed surfaces and flow cytometry analysis.
abstract: Bacteria are ubiquitously distributed throughout our planet, mainly in the form of adherent communities in which cells exhibit specific traits. The mechanisms underpinning the physiological shift in surface-attached bacteria are complex, multifactorial and still partially unclear. Here we address the question of the existence of early surface sensing through implementation of a functional response to initial surface contact. For this purpose, we developed a new experimental approach enabling simultaneous monitoring of free-floating, aggregated and adherent cells via the use of dispersed surfaces as adhesive substrates and flow cytometry analysis. With this system, we analyzed, in parallel, the constitutively expressed GFP content of the cells and production of a respiration probe--a fluorescent reduced tetrazolium ion. In an Escherichia coli strain constitutively expressing curli, a major E. coli adhesin, we found that single cell surface contact induced a decrease in the cell respiration level compared to free-floating single cells present in the same sample. Moreover, we show here that cell surface contact with an artificial surface and with another cell caused reduction in respiration. We confirm the existence of a bacterial cell "sense of touch" ensuring early signalling of surface contact formation through respiration down modulation.
authors: Laboratoire Jean Perrin (CNRS FRE 3231), UPMC, Paris, France.
authors: Jing
authors: J
authors: Geng
authors: Institut Pasteur, Unité de Génétique des Biofilms, Département de Microbiologie, Paris, France.
authors: Christophe
authors: C
authors: Beloin
authors: Institut Pasteur, Unité de Génétique des Biofilms, Département de Microbiologie, Paris, France.
authors: Jean-Marc
authors: JM
authors: Ghigo
authors: Laboratoire Jean Perrin (CNRS FRE 3231), UPMC, Paris, France.
authors: Nelly
authors: N
authors: Henry
mesh_terms: D001422:Bacterial Adhesion / Q000502:physiology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D018441:Biofilms / Q000254:growth & development*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D005434:Flow Cytometry / Q000379:methods*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D018613:Microscopy, Confocal; D010101:Oxygen Consumption / Q000502:physiology; D013499:Surface Properties
chemical_list: D001426:Bacterial Proteins; D049452:Green Fluorescent Proteins; C077481:Crl protein, Bacteria