overexpression in affects biofilm formation and cell morphology in response to shear stress.

UNLABELLED

is an opportunistic pathogen causing chronic infections that are related to its ability to form biofilms. Mechanosensitive ion channels (Mcs) are cytoplasmic membrane proteins whose opening depends on a mechanical stress impacting the lipid bilayer. CmpX is a homologue of the small conductance MscS of . The gene is part of a transcriptional unit that is under the control of the cell envelope stress response ECF sigma factor SigX. CmpX was shown to regulate the activity of the hybrid sensor kinase PA1611 involved in the regulation of transition from a planktonic to a biofilm lifestyle. The deletion of leads to increased biofilm formation under static conditions. Herein, the effect of overexpression was investigated by confocal laser scanning microscopy in terms of biofilm formation and architecture, and matrix components production, in dynamic conditions. We show that overexpression of in leads to enhanced and altered biofilm architecture that seems to be associated to increased matrix components and the emergence of filamentous cells. These phenotypic alterations might occur potentially through a shear stress induced by the medium flow rate.

IMPORTANCE

CmpX is involved in biofilm formation and cell filamentation with regards to the medium flow.