engleski

The role of clpB gene in intracellular survival of Francisella tularensis LVS in Acanthamoeba castellanii

Francisella tularensis is a gram-negative facultative intracellular bacterium that can cause a fatal disease, tularemia, in human and animals. This organism has been isolated from over 250 wildlife species, including fish, birds, amphibians, rabbits, squirrels, hares, voles, ticks, and flies. It resists harsh environments, and has been shown to survive in water and mud for more than a year. The natural reservoirs in water are protozoa including many species of amoeba. This bacterial pathogen is known for its ability to cause a disease in humans after exposure to as few as 10 cells and has raised considerable concern as a potential bioterrorist agent. The aim of this study was to determine the role of clpB gene in intercellular survival and repilcation of F. tularensis LVS (the wild type strain) in Acanthamoeba castellanii. Previous results have shown survival and growth of F. tularensis LVS strain in A. castellanii. The role of F. tularensis clpB gene in intracellular survival and replication of bacteria inside A. castellanii cells is unknown. Our results showed that the wild type strain of F. tularensis LVS replicated in A. castellanii, and survived in amoeba up to 7 days. The mutant with disrupted clpB gene that encodes general stress protein (FTTO624) showed just a slight growth defect in A. castellanii cells and survived in the cells up to 7 days after infection similar to the wt strain. However, similar to the infection in macrophages cells, in A. castellanii cells clpB gene plays an important role in F. tularensis intracellular replication.

Francisella tularensis; amoeba; clpB mutant

nije evidentirano