Revisiting Campylobacter jejuni Virulence and Fitness Factors: Role in Sensing, Adapting, and Competing

Abstract

Campylobacter jejuni is the leading cause of bacterial foodborne gastroenteritis world wide and represents a major public health concern. Over the past two decades, significant progress in functional genomics, proteomics, enzymatic-based virulence profiling (EBVP), and the cellular biology of C. jejuni have improved our basic understanding of this important pathogen. We review key advances in our understanding of the multitude of emerging virulence factors that influence the outcome of C. jejuni-mediated infections. We highlight, the spatial and temporal dynamics of factors that promote C. jejuni to sense, adapt and survive in multiple hosts. Finally, we propose cohesive research directions to obtain a comprehensive understanding of C. jejuni virulence mechanisms.

Keywords: Campylobacter jejuni; adaptation; host-pathogen; sensing; stress and survival; virulence.

Figure 1

Overview of C. jejuni reservoirs and transmission routes of infection. C. jejuni reside in the GI tract of chickens, where the bacteria can be spread through consumption of contaminated poultry products. C. jejuni transmission can also occur via the consumption of contaminated raw cows drinking milk (RDM) which can occur during the milking process, most commonly via fecal contamination of udders. Pigs are also recognized as reservoirs of C. jejuni. Contamination of the environment can also occur via host fecal contamination. C. jejuni can persist for long periods in feces, milk and water, especially at temperatures close to 4℃. In adverse conditions, C jejuni converts to a viable nonculturable form that can be reactivated when ingested.