Dissertation: Intestinal bacteria Campylobacter jejuni adapts easily to surroundings

PhD Candidate Anne-Xander van der Stel has discovered that the common intestinal bacteria Campylobacter jejuni can adjust its own respiratory chain, metabolism and energy supply in order to survive in an oxygen-poor environment such as our intestines.

Campylobacter jejuni (C. jejuni) is an intestinal bacteria that occurs in many animal species, but only causes diarrhoea in humans. People often become infected with the bacteria by eating contaminated poultry, as the chicken’s intestines contain vast numbers of the Campylobacter bacteria. The intestines are an oxygen-poor environment, with an irregular supply of nutrients. In order to survive in this environment, the bacteria must be able to easily adapt to their surroundings.

Bacteria guarantees energy supply

C. jejuni uses oxygen to ‘breathe’, but it can also use alternatives such as fumarate, tetrathionate and nitrate. Anne Xander van der Stel has discovered that oxygen is an important factor in controlling the respiratory chain. “C. jejuni adjusts its respiration in such a way that its energy supply is always guaranteed. We have also found a system specific to Campylobacter that regulates respiration in order to make optimal use of the available nutrients. That gives the bacteria a significant advantage in growth.”

Adjusting metabolism

Van der Stel has also discovered that C. jejuni adjusts its metabolism to the nutrients available in its living environment. Further research has indicated that this mechanism is dependent on the accumulation of an intermediate product of the bacteria’s metabolism. “My PhD research provides an important contribution to our insight into how Campylobacter adapts to its environment”, says Van der Stel. “Considering the problem of antibiotics resistance, this is vital for the development of targeted antimicrobial treatments.”