Evidence for intracellular Pseudomonas aeruginosa
Zachary J Resko1, Rachel F Suhi1, Adam V Thota1
1Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, USA.
Abstract:
Pseudomonas aeruginosa is a significant cause of global morbidity and mortality. Although it is often regarded as an extracellular pathogen toward human cells, numerous investigations report its ability to survive and replicate within host cells, and additional studies demonstrate specific mechanisms enabling it to adopt an intracellular lifestyle. This ability of P. aeruginosa remains less well-investigated than that of other intracellular bacteria, although it is currently gaining attention. If intracellular bacteria are not killed after entering host cells, they may instead receive protection from immune recognition and experience reduced exposure to antibiotic therapy, among additional potential advantages shared with other facultative intracellular pathogens. For this review, we compiled studies that observe intracellular P. aeruginosa across strains, cell types, and experimental systems in vitro, as well as contextualize these findings with the few studies that report similar observations in vivo. We also seek to address key findings that drove the perception that P. aeruginosa remains extracellular in order to reconcile what is currently understood about intracellular pathogenesis and highlight open questions regarding its contribution to disease.
Insights
Pseudomonas aeruginosa can live inside human cells, offering protection from antibiotics and immune responses. This review explores the evidence for this intracellular lifestyle and its implications for disease.
Area of Science:
- Microbiology
- Pathogenesis
- Bacterial Infections
Background:
- Pseudomonas aeruginosa is a major cause of illness and death worldwide.
- While often considered extracellular, P. aeruginosa can survive and multiply within host cells.
- Its intracellular lifestyle is less understood than that of other intracellular bacteria but is gaining attention.
Purpose of the Study:
- To review studies on intracellular Pseudomonas aeruginosa.
- To reconcile the understanding of P. aeruginosa's intracellular pathogenesis.
- To highlight knowledge gaps regarding its role in disease.
Main Methods:
- Compilation of in vitro studies observing intracellular P. aeruginosa across various strains, cell types, and experimental systems.
- Contextualization of in vitro findings with limited in vivo studies reporting similar observations.
- Analysis of factors contributing to the perception of P. aeruginosa as primarily extracellular.
Main Results:
- Evidence supports P. aeruginosa's ability to adopt an intracellular lifestyle.
- Intracellular survival may offer protection from host immunity and antibiotic treatment.
- Studies demonstrate specific mechanisms enabling intracellular invasion and replication.
Conclusions:
- Pseudomonas aeruginosa possesses an intracellular dimension to its pathogenesis.
- Further research is needed to fully understand the implications of intracellular P. aeruginosa in disease.
- Reconciling extracellular and intracellular behaviors is key to understanding P. aeruginosa infections.
