Relation of Capsular Polysaccharide Production and Colonial Cell Organization to Colony Morphology in Vibrio parahaemolyticus
AUTOR(ES)
Enos-Berlage, Jodi L.
FONTE
American Society for Microbiology
RESUMO
Vibrio parahaemolyticus is a ubiquitous, gram-negative marine bacterium that undergoes phase variation between opaque and translucent colony morphologies. The purpose of this study was to determine the factor(s) responsible for the opaque and translucent phenotypes and to examine cell organization within both colony types. Examination of thin sections of ruthenium red-stained bacterial cells by electron microscopy revealed a thick, electron-dense layer surrounding the opaque cells that was absent in preparations from translucent strains. Extracellular polysaccharide (EPS) material was extracted from both opaque and translucent strains, and the opaque strain was shown to produce abundant levels of polysaccharide, in contrast to the translucent strain. Compositional analysis of the EPS identified four major sugars: glucose, galactose, fucose, and N-acetylglucosamine. Confocal scanning laser microscopy was used to investigate cell organization within opaque and translucent colonies. Cells within both types of colonies exhibited striking organization; rod-shaped cells were aligned parallel to one another and perpendicular to the agar surface throughout the depth of the colony. Cells within translucent colonies appeared more tightly packed than cells in opaque colonies. In addition, a dramatic difference in the structural integrity of these two colony types was observed. When colonies were perturbed, the cell organization of the translucent colonies was completely disrupted while the organization of the opaque colonies was maintained. To our knowledge, this study represents the first description of how cells are organized in the interior of a viable bacterial colony. We propose that the copious amount of EPS produced by the opaque strain fills the intercellular space within the colony, resulting in increased structural integrity and the opaque phenotype.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=110996Documentos Relacionados
- Multiple Regulators Control Capsular Polysaccharide Production in Vibrio parahaemolyticus
- Study of Capsular Polysaccharide from Vibrio parahaemolyticus
- Relation of capsular materials and colony opacity to virulence of Vibrio vulnificus.
- Vibrio parahaemolyticus scrABC, a Novel Operon Affecting Swarming and Capsular Polysaccharide Regulation
- Differential Expression of Vibrio vulnificus Capsular Polysaccharide