Journal article
Interactions between the environmental pathogen Listeria monocytogenes and a free-living protozoan (Acanthamoeba castellanii)
Environmental microbiology, Vol.9(4), pp.913-922
04/2007
Handle:
https://hdl.handle.net/2376/107582
PMID: 17359263
Abstract
Listeria monocytogenes can cause severe disease in animal hosts, but it has no recognized animal host reservoir. We tested the hypothesis that L. monocytogenes retains virulence traits to survive predation by amoebae and that listeriolysin O plays a crucial role in this process. Co-culturing of L. monocytogenes and Acanthamoeba castellanii demonstrated that L. monocytogenes does not actively kill amoebae, but in the presence of amoebae, high bacterial population densities can be maintained over a period of at least 96 h. A gentamicin protection assay demonstrated that there is no significant difference in the ability to survive predation between serovars (4b versus 1/2a and 1/2c; P = 0.08) and between five species of Listeria (P = 0.14). Three of these species do not harbour the hly gene responsible for listeriolysin O production. A hly knockout strain had poorer survival compared with the parental strain (P = 0.04 at 24 h; P = 0.04 at 48 h; P = 0.02 at 72 h) and electron microscopy was consistent with a wild-type strain being able to escape the phagosome whereas the hly knockout strain did not appear to have this ability. Thus, while there is weak evidence that listeriolysin O can contribute to improved survival after ingestion by amoebae, listeriolysin O does not appear to provide a significant selective advantage under the conditions of this study.
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Details
- Title
- Interactions between the environmental pathogen Listeria monocytogenes and a free-living protozoan (Acanthamoeba castellanii)
- Creators
- Xiaohui Zhou - Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164-7040, USAJennifer ElmoseDouglas R Call
- Publication Details
- Environmental microbiology, Vol.9(4), pp.913-922
- Academic Unit
- Paul G. Allen School for Global Animal Health
- Publisher
- England
- Identifiers
- 99900546967401842
- Language
- English
- Resource Type
- Journal article