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Imaging InlC Secretion to Investigate Cellular Infection by the Bacterial Pathogen Listeria monocytogenes
Published on: September 19, 2013
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Listeria monocytogenes ActA: a new function for a 'classic' virulence factor
Laetitia Travier1, Marc Lecuit2
1Institut Pasteur, Biology of Infection Unit, 75015 Paris, France; Inserm U1117, Paris, France.
Current Opinion in Microbiology
|March 4, 2014
Summary
Listeria monocytogenes (Lm) uses its ActA protein not only inside cells but also outside. This extracellular function promotes bacterial aggregation and biofilm formation, aiding gut colonization and transmission.
Area of Science:
- Microbiology
- Infectious Diseases
- Bacterial Pathogenesis
Background:
- Listeria monocytogenes (Lm) is a significant foodborne pathogen causing severe human infections.
- Lm is a facultative intracellular bacterium that invades host cells and disseminates systemically.
- The surface protein ActA is a key virulence factor essential for intracellular motility and spread.
Purpose of the Study:
- To investigate the extracellular functions of the Lm ActA protein.
- To understand ActA's role in bacterial aggregation, biofilm formation, and gut colonization.
Main Methods:
- In vitro and in vivo experiments were conducted.
- Analysis focused on bacterial aggregation and biofilm formation mediated by ActA.
- Studies assessed long-term gut lumen colonization.
Main Results:
- The bacterial surface protein ActA mediates Lm aggregation and biofilm formation extracellularly.
- ActA promotes long-term colonization of the gut lumen.
- Extracellular ActA activity favors Lm transmission.
Conclusions:
- The ActA protein possesses previously unrecognized extracellular functions.
- These extracellular roles of ActA contribute to Lm's persistence and transmission.
- ActA's dual intra- and extracellular functions highlight its critical importance in Lm pathogenesis.
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