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Shigella flexneri Adapts to Niche-Specific Stresses through Modifications in Cell Envelope Composition and Decoration
Alice Ascari1,2, Jack K Waters2, Renato Morona1
1School of Biological Sciences, Department of Molecular and Biomedical Science, Research Centre for Infectious Diseases, University of Adelaide, Adelaide 5005, South Australia, Australia.
ACS Infectious Diseases
|July 26, 2023
Summary
Shigella flexneri adapts to host antimicrobials like fatty acids (FAs) and deoxycholate (DOC) by altering its cell envelope. Its very-long O antigen (VL-Oag) LPS protects against FAs but increases susceptibility to DOC.
Area of Science:
- Microbiology
- Bacterial Pathogenesis
- Host-Pathogen Interactions
Background:
- Shigella flexneri causes shigellosis globally.
- The pathogen must adapt to host antimicrobials like fatty acids (FAs) and deoxycholate (DOC) in the gastrointestinal tract.
Purpose of the Study:
- To investigate Shigella flexneri cell envelope adaptations to FA and DOC exposure.
- To identify novel lipopolysaccharide (LPS)-based resistance strategies.
Main Methods:
- Analysis of bacterial membrane fatty acid composition.
- Interrogation of lipopolysaccharide (LPS) composition and expression.
- Assessment of pathogen resistance following FA and DOC exposure.
Main Results:
- Fatty acids (FAs) and deoxycholate (DOC) alter S. flexneri membrane fatty acid and LPS compositions.
- Expression of very-long O antigen (VL-Oag) LPS is crucial for protecting against antimicrobial FAs.
- VL-Oag LPS expression increases S. flexneri susceptibility to DOC stress.
Conclusions:
- S. flexneri employs novel LPS-based strategies for stress mitigation.
- Regulation of cell envelope constituents, particularly VL-Oag LPS, is vital for adapting to diverse host stresses during infection.
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