Campylobacter jejuni gene expression in response to iron limitation and the role of Fur

Campylobacter jejuni is a zoonotic pathogen and the most common cause of bacterial foodborne diarrhoeal illness worldwide. To establish intestinal colonization prior to either a commensal or pathogenic interaction with the host, C. jejuni will encounter iron-limited niches where there is likely to be intense competition from the host and normal microbiota for iron. To gain a better understanding of iron homeostasis and the role of ferric uptake regulator (Fur) in iron acquisition in C. jejuni, a proteomic and transcriptome analysis of wild-type and fur mutant strains in iron-rich and iron-limited growth conditions was carried out. All of the proposed iron-transport systems for haemin, ferric iron and enterochelin, as well as the putative iron-transport genes p19, Cj1658, Cj0177, Cj0178 and cfrA, were expressed at higher levels in the wild-type strain under iron limitation and in the fur mutant in iron-rich conditions, suggesting that they were regulated by Fur. Genes encoding a previously uncharacterized ABC transport system (Cj1660-Cj1663) also appeared to be Fur regulated, supporting a role for these genes in iron uptake. Several promoters containing consensus Fur boxes that were identified in a previous bioinformatics search...Continue Reading