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A Semi-quantitative Approach to Assess Biofilm Formation Using Wrinkled Colony Development
Published on: June 7, 2012
Quorum sensing-dependent biofilms enhance colonization in Vibrio cholerae
1Department of Microbiology and Molecular Genetics, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
Developmental Cell
|October 11, 2003
Summary
Quorum sensing-deficient Vibrio cholerae form thicker biofilms. This impacts Vibrio polysaccharide synthesis and acid resistance, suggesting quorum sensing regulates biofilm exit for infection.
Area of Science:
- Microbiology
- Bacterial Pathogenesis
- Molecular Biology
Background:
- Vibrio cholerae causes cholera, a diarrheal disease.
- V. cholerae forms complex surface-associated biofilms through an incompletely understood process.
- Biofilm formation and regulation are critical for V. cholerae pathogenesis.
Purpose of the Study:
- To investigate the role of quorum sensing in V. cholerae biofilm development.
- To elucidate the regulatory mechanisms controlling biofilm formation in V. cholerae.
- To understand the relationship between biofilm properties, quorum sensing, and V. cholerae infectivity.
Main Methods:
- Generation and analysis of quorum sensing-deficient V. cholerae mutants (hapR).
- Microarray analysis to assess gene expression in biofilm-associated bacteria.
- Comparison of biofilm thickness, acid resistance, and colonization capacity between wild-type and mutant strains.
Main Results:
- Quorum sensing-deficient mutants exhibit thicker biofilms compared to wild-type V. cholerae.
- Expression of Vibrio polysaccharide synthesis (vps) operons is enhanced in hapR mutants.
- Quorum sensing-deficient biofilms show increased acid resistance but reduced colonization capacity.
Conclusions:
- Quorum sensing, mediated by CqsA and HapR, represses vps gene expression, influencing biofilm structure.
- Biofilm acid resistance is enhanced in quorum sensing-deficient V. cholerae.
- Quorum sensing likely promotes cellular exit from biofilms, a crucial step for V. cholerae colonization after gastric acid exposure.
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