PNNL

Abstract

Campylobacter jejuni is likely the most common bacterial cause of gastroenteritis worldwide, responsible for millions of cases of inflammatory diarrhea characterized by severe abdominal cramps and blood and leukocytes in the stool. Further, C. jejuni in-fections are associated with post-infection sequelae in developed countries and mal-nutrition and growth-stunting in low- and middle-income countries. Despite the in-creasing prevalence of the disease, (campylobacteriosis,) and the recognition that this pathogen is a serious health threat, our understanding of C. jejuni pathogenesis re-mains incomplete. In this review, we focus on the Campylobacter secretion systems proposed to contribute to host-cell interactions and survival in the host. Moreover, we have applied a genomics approach to defining the structural and mechanistic features of C. jejuni type III, IV, and VI secretion systems. Special attention is focused on the flagellar type III secretion system and the prediction of putative effectors, given that the proteins exported via this system are essential for host cell invasion and the in-flammatory response. We conclude that C. jejuni does not possess a type IV secretion system and relies on the type III and type VI secretion systems to establish a niche and potentiate disease.