engleski

In vivo virulence of Campylobacter jejuni exposed to different environmental stresses

Campylobacters are the most common bacteria causing human gastroenteritis and are mainly transmitted through foods. As foodborne pathogens they have developed survival mechanisms to overcome the stresses they face in the environment and during food processing. However, the link between environmental stress exposure and its virulence properties of Campylobacter is not often investigated. The aim of our study was to evaluate the effect of selected environmental stress factors: temperature shift, starvation and atmospheric oxygen exposure on the ability of Campylobacter to cause disseminated infection in mice. BALB/c mice were intravenously injected with stressed campylobacters and bacterial invasion into their livers and spleens was followed. At different time points after infection, organs were asseptically removed, dissected and the number of CFU was determined. Simultaneously, paraffin sections were prepaired for histopathological evaluation. According to our results, nutrient insufficiency was the most powerful stress factor which significantly decreased infectious potential of C. jejuni, according to the lowest bacterial load in examined organs. Heat shock was also capable to modulate the in vivo virulence of C. jejuni, but in a lesser extent then starvation. To the opposite, oxidative stress increased survival of C. jejuni inside the livers and spleens of infected mice.

Campylobacter jejuni; environmental stress; virulence; mice

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