The predominant mode of growth of bacteria in the environment is within sessile, matrix-enclosed communities known as biofilms. Biofilms often complicate chronic and difficult-to-treat infections by protecting bacteria from the immune system, decreasing antibiotic efficacy, and dispersing @entity1358 to distant body sites. While the biology of bacterial biofilms has become a major focus of microbial research, the regulatory mechanisms of biofilm development remain poorly defined and those of dispersal are unknown. Here we establish that the RNA binding global regulatory protein CsrA ( @entity505 storage regulator) of @entity2624 serves as both a repressor of biofilm formation and an activator of biofilm dispersal under a variety of culture conditions. Ectopic expression of the @entity2624 csrA gene repressed biofilm formation by related bacterial pathogens. A csrA knockout mutation enhanced biofilm formation in @entity526 strains that were defective for extracellular, surface, or regulatory factors previously implicated in biofilm formation. In contrast, this csrA mutation did not affect biofilm formation by a glgA (glycogen synthase) knockout mutant. Complementation studies with glg genes provided further genetic evidence that the effects of CsrA on biofilm formation are mediated largely through the regulation of intracellular glycogen biosynthesis and catabolism. Finally, the expression of a chromosomally encoded csrA'-'lacZ translational fusion was dynamically regulated during biofilm formation in a pattern consistent with its role as a repressor. We propose that global regulation of central @entity505 flux by CsrA is an extremely important feature of @entity526 biofilm development.

Biofilm formation and dispersal under the influence of the global regulator CsrA of XXXX .

@entity505 :: ('MESH:D002244', 'Chemical') :: ['carbon'] @entity1358 :: ('MESH:D002292', 'Disease') :: ['planktonic cells'] @entity2624 :: ('83333', 'Species') :: ['Escherichia coli K-12', 'E. coli K-12'] @entity526 :: ('562', 'Species') :: ['E. coli']
@entity526 :: (562,Species) :: ['Escherichia coli']
