Inhibition of AI-2 Quorum Sensing and Biofilm Formation in Campylobacter jejuni by Decanoic and Lauric Acids

Abstract

<i>Campylobacter jejuni</i> is a major bacterial cause of human diarrheal diseases worldwide. Despite its sensitivity to environmental stresses, <i>C. jejuni</i> ubiquitously distributes throughout poultry production chains. Biofilm formation mediated by quorum sensing is suggested to be critical to the survival of <i>C. jejuni</i> in agroecosystem. <i>C. jejuni</i> possesses LuxS, the enzyme involved in the production of autoinducer-2 (AI-2) signaling molecules. In this study, two fatty acids, namely decanoic acid and lauric acid, were identified to be effective in inhibiting AI-2 activity of <i>C. jejuni</i>. Both decanoic acid and lauric acid at 100 ppm inhibited ∼90% AI-2 activity (<i>P</i> < 0.05) of <i>C. jejuni</i> without bacterial inactivation. The biofilm biomass of two <i>C. jejuni</i> strains was reduced by 10-50% (<i>P</i> < 0.05) after treatment by both fatty acids, while increased biofilm formation was observed for one <i>C. jejuni</i> strain. In addition, both fatty acids effectively reduced the motility of all tested <i>C. jejuni</i> strains. These findings can aid in developing alternative <i>C. jejuni</i> control strategies in agri-food and clinical settings.