Cross-membrane cooperation among bacteria can facilitate intracellular pathogenesis
Daniel Schator1, Naren G Kumar1, Samuel Joseph U Chong1
1Herbert Wertheim School of Optometry & Vision Science, University of California Berkeley, Berkeley, CA, USA.
Abstract:
Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen able to cause life- and sight-threatening infections. Once considered an extracellular pathogen, numerous studies have shown it can survive intracellularly. Previously, we showed that P. aeruginosa inside cells can diversify into distinct subpopulations in vacuoles and the cytoplasm. Here, we report that the transition from vacuoles to cytoplasm requires collaboration with the extracellular subpopulation, through Ca2+ influx enabled by their type III secretion system (T3SS) translocon pore proteins. Moreover, we show that collaboration among P. aeruginosa subpopulations can contribute to disseminating intracellular bacteria in vivo in a mouse infection model. This study lays the groundwork for future investigations into how cooperation between extracellular and intracellular bacteria within the host contributes to disease progression and persistence.
Insights
Pseudomonas aeruginosa bacteria cooperate between extracellular and intracellular populations to transition within host cells. This bacterial collaboration, requiring calcium influx, aids in spreading infection in vivo.
Area of Science:
- Microbiology
- Cell Biology
- Infectious Diseases
Background:
- Pseudomonas aeruginosa is a Gram-negative bacterium causing severe infections.
- While traditionally extracellular, P. aeruginosa can survive and diversify within host cells.
- Distinct intracellular subpopulations (vacuolar and cytoplasmic) have been identified.
Purpose of the Study:
- To investigate the mechanism of P. aeruginosa transition from vacuoles to cytoplasm.
- To explore the role of extracellular bacteria in facilitating intracellular bacterial movement.
- To examine the contribution of bacterial cooperation to dissemination in vivo.
Main Methods:
- Investigated calcium (Ca2+) influx.
- Analyzed the type III secretion system (T3SS) translocon pore proteins.
- Utilized a mouse infection model to study bacterial dissemination.
Main Results:
- The transition of P. aeruginosa from vacuoles to cytoplasm requires extracellular bacterial collaboration.
- Calcium influx, mediated by T3SS translocon pore proteins, is essential for this transition.
- Cooperation between extracellular and intracellular P. aeruginosa promotes bacterial dissemination in vivo.
Conclusions:
- Extracellular P. aeruginosa actively facilitates the intracellular relocation of other bacterial populations.
- Bacterial cooperation and T3SS are critical for P. aeruginosa pathogenesis and persistence.
- Understanding inter-population bacterial dynamics is key to combating P. aeruginosa infections.
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