TY - JOUR
T1 - Inactivation of the SecA2 protein export pathway in Listeria monocytogenes promotes cell aggregation, impacts biofilm architecture and induces biofilm formation in environmental condition
AU - Renier, Sandra
AU - Chagnot, Caroline
AU - Deschamps, Julien
AU - Caccia, Nelly
AU - Szlavik, Julie
AU - Joyce, Susan A.
AU - Popowska, Magdalena
AU - Hill, Colin
AU - Knøchel, Susanne
AU - Briandet, Romain
AU - Hébraud, Michel
AU - Desvaux, Mickaël
N1 - Special Issue: Environmental Lifestyles and Transmission of Pathogens
PY - 2014/4
Y1 - 2014/4
N2 - Summary: Listeria monocytogenes has a dichotomous lifestyle, existing as an ubiquitous saprophytic species and as an opportunistic intracellular pathogen. Besides its capacity to grow in a wide range of environmental and stressful conditions, L.monocytogenes has the ability to adhere to and colonize surfaces. Morphotype variation to elongated cells forming rough colonies has been reported for different clinical and environmental isolates, including biofilms. This cell differentiation is mainly attributed to the reduced secretion of two SecA2-dependent cell-wall hydrolases, CwhA and MurA. SecA2 is a non-essential SecA paralogue forming an alternative translocase with the primary Sec translocon. Following investigation at temperatures relevant to its ecological niches, i.e. infection (37°C) and environmental (20°C) conditions, inactivation of this SecA2-only protein export pathway led, despite reduced adhesion, to the formation of filamentous biofilm with aerial structures. Compared to the wild type strain, inactivation of the SecA2 pathway promoted extensive cell aggregation and sedimentation. At ambient temperature, this effect was combined with the abrogation of cell motility resulting in elongated sedimented cells, which got knotted and entangled together in the course of filamentous-biofilm development. Such a cell differentiation provides a decisive advantage for listerial surface colonization under environmental condition. As further discussed, this morphotypic conversion has strong implication on listerial physiology and is also of potential significance for asymptomatic human/animal carriage.
AB - Summary: Listeria monocytogenes has a dichotomous lifestyle, existing as an ubiquitous saprophytic species and as an opportunistic intracellular pathogen. Besides its capacity to grow in a wide range of environmental and stressful conditions, L.monocytogenes has the ability to adhere to and colonize surfaces. Morphotype variation to elongated cells forming rough colonies has been reported for different clinical and environmental isolates, including biofilms. This cell differentiation is mainly attributed to the reduced secretion of two SecA2-dependent cell-wall hydrolases, CwhA and MurA. SecA2 is a non-essential SecA paralogue forming an alternative translocase with the primary Sec translocon. Following investigation at temperatures relevant to its ecological niches, i.e. infection (37°C) and environmental (20°C) conditions, inactivation of this SecA2-only protein export pathway led, despite reduced adhesion, to the formation of filamentous biofilm with aerial structures. Compared to the wild type strain, inactivation of the SecA2 pathway promoted extensive cell aggregation and sedimentation. At ambient temperature, this effect was combined with the abrogation of cell motility resulting in elongated sedimented cells, which got knotted and entangled together in the course of filamentous-biofilm development. Such a cell differentiation provides a decisive advantage for listerial surface colonization under environmental condition. As further discussed, this morphotypic conversion has strong implication on listerial physiology and is also of potential significance for asymptomatic human/animal carriage.
U2 - 10.1111/1462-2920.12257
DO - 10.1111/1462-2920.12257
M3 - Journal article
C2 - 24102749
SN - 1462-2912
VL - 16
SP - 1176
EP - 1192
JO - Environmental Microbiology
JF - Environmental Microbiology
IS - 4
ER -