engleski

The link between survival and infectivity of Campylobacter jejuni cells under changing environmental conditions

Bacteria are exposed to different stress conditions in the environment, or during food production as well as in the host. Temperature changes, availability of nutrients or the presence of toxic substances and antimicrobials are some of them. Despite the lack of many stress response mechanisms that other food-borne bacteria possess, campylobacters display a distinct survival potential in the extraintestinal environment and consequently also high incidence as a cause of human infections. This is at least partially the consequence of microbial adaptation to environmental stresses (1, 2). Consequently, discovering the link between survival and infectivity is vital for risk assessment purposes and for establishing the dynamics of potential food-borne infection. Since there are not many publications in this field, we investigated C. jejuni following heat shock, starvation and oxidative stress. The environmental impact on physiology, survival and virulence properties were studied by culturability, viability, as well as the ability of adhesion, invasion and intracellular survival within in vitro cell culure model using Caco-2 intestinal cells and murine macrophages J774 (3). With additional in vivo experiments in the murine model we investigated the influence of Campylobacter stress response on its virulence potential. At different time points after infection bacterial spreading and tissue invasion of infected BALB/c mice was determined (2, 4). (1) Klancnik, A. et al.(2006):Int.J.Food Microbiol., 112:200-207. (2) Klancnik, A. et al.(2009):Res.Microbiol. (Article in press) (3) Sikic Pogacar, M. et al.(2009):Int.J.Food Microbiol., 129:68-73. (4) Vuckovic, D. et al.(1998):Microb.Pathog., 24:263-268.

Campylobacter; stress response; cell lines; mice

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