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Ingested Listeria monocytogenes survive and multiply in protozoa
1Staatliches Medizinaluntersuchungsamt Braunschweig, Federal Republic of Germany.
Abstract:
Listeria monocytogenes cells are ingested by protozoa such as Acanthamoeba sp. or Tetrahymena pyriformis. However, they are not killed, but survive within the protozoa and may multiply intracellularly. The protozoa are lysed within about 8 days, releasing viable L. monocytogenes. No co-existence was observed between L. monocytogenes and Tetrahymena. A co-culture of L. monocytogenes and Acanthamoeba sp. showed a decay of locomotive forms and release of listeria from vegetative protozoan cells whereas the bacteria were destroyed in cysts. These phenomena provide an insight into the pathogenesis of listeria infection in man and warm-blooded animals because intracellular processes occurring in protozoa after ingestion of L. monocytogenes may be similar to those observed in mammalian cells.
Insights
Listeria monocytogenes survive and multiply within protozoa like Acanthamoeba, eventually being released. This protozoan interaction offers insights into Listeria pathogenesis in animals and humans.
Area of Science:
- Microbiology
- Cell Biology
- Pathogenesis
Background:
- Listeria monocytogenes is a foodborne pathogen causing listeriosis.
- Protozoa are ubiquitous microorganisms that can interact with bacteria.
Purpose of the Study:
- To investigate the interaction between Listeria monocytogenes and protozoa.
- To understand the survival and multiplication mechanisms of L. monocytogenes within protozoa.
- To explore the implications for Listeria pathogenesis.
Main Methods:
- Co-culture experiments with L. monocytogenes and Acanthamoeba sp.
- Co-culture experiments with L. monocytogenes and Tetrahymena pyriformis.
- Observation of bacterial survival, multiplication, and release.
Main Results:
- L. monocytogenes survived and multiplied intracellularly within Acanthamoeba.
- Protozoa lysed, releasing viable L. monocytogenes.
- No co-existence was observed between L. monocytogenes and Tetrahymena.
- L. monocytogenes were destroyed in Acanthamoeba cysts but released from vegetative cells.
Conclusions:
- Protozoa can serve as a reservoir for L. monocytogenes.
- Intracellular processes in protozoa may mimic those in mammalian cells during Listeria infection.
- This interaction provides a model for understanding Listeria pathogenesis.