Environmental Determinants of Vibrio cholerae Biofilm Development

Abstract

Vibrio cholerae is a versatile bacterium that flourishes in diverse environments, including the human intestine, rivers, lakes, estuaries, and the ocean. Surface attachment is believed to be essential for colonization of all of these natural environments. Previous studies have demonstrated that the vps genes, which encode proteins required for exopolysaccharide synthesis and transport, are required for V. cholerae biofilm development in Luria-Bertani broth. In this work, we showed that V. cholerae forms vps-dependent biofilms and vps-independent biofilms. The vps-dependent and -independent biofilms differ in their environmental activators and in architecture. Our results suggest that environmental activators of vps-dependent biofilm development are present in freshwater, while environmental activators of vps-independent biofilm development are present in seawater. The distinct environmental requirements for the two modes of biofilm development suggest that vps-dependent biofilm development and vps-independent biofilm development may play distinct roles in the natural environment.

Extracellular matrix structure governs invasion resistance in bacterial biofilms

“…Biofilm production is strongly implicated in V. cholerae disease transmission and environmental survival on biotic and abiotic surfaces (Watnick et al, 2001;Kierek and Watnick, 2003;Matz et al, 2005;Nielsen et al, 2006;Fong et al, 2010;Tamayo et al, 2010). We find that biofilms exclude immotile planktonic cells from gaining access to the interior and from remaining bound to the biofilm surface.…”

Sticky Situations: Key Components That Control Bacterial Surface Attachment

“…In contrast, Ca 2ϩ was found to enhance vps-independent biofilm formation, with removal of Ca 2ϩ (freshwater is calcium poor) resulting in the disintegration of V. cholerae biofilms as well as the biofilms of several other Vibrio species (77). The finding suggests that environmental activators of vps-dependent biofilm development are present in freshwater in association with arthropods while environmental activators of vps-independent biofilm development are present in calcium-rich seawater (76). Vibrio vulnificus also exhibits a differential dependency of attachment on environmental conditions, with nutrient and glucose availability but not sodium chloride availability of the marine environment serving as factors altering adherence (101).…”

“…Vibrio cholerae is both an inhabitant of estuarine environments and the etiologic agent of the diarrheal disease cholera. Attachment by V. cholerae is enhanced by the presence of monosaccharides either by supplementation of the growth medium or by degradation of the polysaccharide surface (e.g., the chitinaceous surface of arthropods) to which the cells are attached (76). A lack of monosaccharides impairs V. cholerae biofilm formation at the monolayer stage.…”

“…A lack of monosaccharides impairs V. cholerae biofilm formation at the monolayer stage. These environmental signals have been identified as activators of vps gene transcription that are responsible for synthesis of the Vibrio polysaccharide (VPS) and biofilm formation (76). In contrast, Ca 2ϩ was found to enhance vps-independent biofilm formation, with removal of Ca 2ϩ (freshwater is calcium poor) resulting in the disintegration of V. cholerae biofilms as well as the biofilms of several other Vibrio species (77).…”

Curli Fibers Are Required for Development of Biofilm Architecture in Escherichia coli K‐12 and Enhance Bacterial Adherence to Human Uroepithelial Cells

“…The formation of mature biofilm architecture of several bacterial species has been described as a developmental differentiation process (25). The mature and differentiated three-dimensional structure of biofilms is characterized by mushroom or pillar shaped bacterial clusters surrounded by water channels allowing the influx of nutrients and the efflux of waste products (8,9,11,19,33,40,42). In contrast to the extensive characterization of biofilm structure, little is known about the molecular mechanisms underlying the maturation and differentiation of the biofilm.…”