Campylobacter biofilms

Abstract

Campylobacter infection is one of the most widespread foodborne gastroenteritis worldwide. As a commensal microbe in the intestinal tracts of food-producing animals, Campylobacter easily enters the food chain and eventually transmits to human hosts through the consumption of contaminated food products. The survival of Campylobacter in food chain remains as a paradox considering its fastidious growth requirement in laboratory settings and ubiquitous presence in unfavorable environment. Biofilm is suggested as a key persistence mechanism used by Campylobacter during its transmission from animals to humans. This review summarizes Campylobacter biofilm characteristics, identifies biological and non-biological factors that influence biofilm formation, and discusses the control strategies. Overall, biofilm formation ability shows strain-to-strain variation in Campylobacter and is affected by the presence of other co-cultivated bacteria. Carbohydrates and eDNA are recognized as significant portions of extracellular polymeric substances (EPS) in Campylobacter biofilm. Advanced techniques such as super resolution microscopy and chemical imaging platforms can demonstrate the structure and EPS biochemical compositions. Biofilm formation relies on various biological factors (e.g., flagella, cell surface hydrophobicity, and quorum sensing) and environmental factors (e.g., substrate properties, hydrodynamic condition, and nutrients). Different biological and inorganic compounds can inactivate Campylobacter biofilm along with the feasibility of discovering specific chemicals to quench quorum sensing of this microbe so as to indirectly reduce its biofilm. Taken together, Campylobacter biofilm research is still in its infancy and future research can focus on investigating dormancy state and antimicrobial resistance evolution in biofilms as well as in vivo characterization.

Keywords: Biofilm; Campylobacter; Food safety; Transmission.