Background and aims: Campylobacter jejuni can cause a spectrum of diseases in humans ranging from enteritis and diarrhoea to severe inflammation, profuse bloody diarrhoea and chronic relapsing infection. Norepinephrine (NE) levels in the intestine increase under conditions of stress and trauma and are thought to result in spill over of NE into the intestinal lumen. NE is known to stimulate the growth of a range of bacterial species and to increase the pathogenicity of E. coli. The aim of this work was to determine the effects of this neurotransmitter on the pathogenic potential of C. jejuni in a model system.
Methods: C. jejuni was grown in iron replete and iron-limited media in the presence and absence of 100 μM NE. Several virulence-associated characteristics, including motility and cell invasion, were measured.
Results: When C. jejuni was grown in iron-limited media in the presence of NE, growth rate, motility and invasion of cultured epithelial cells were increased compared to cultures grown in the absence of the neurotransmitter. Bacteria exposed to NE during growth also caused greater subsequent disruption of cultured epithelial cell monolayers, inducing widespread breakdown of tight junctions.
Conclusion: Exposure to NE causes an increase in virulence-associated properties of campylobacter. Stress and concomitant infection may therefore be contributory factors to the variable presentation of this disease.