Transcriptional and translational expression patterns associated with immobilized growth of Campylobacter jejuni

Abstract

Although Campylobacter jejuni is a leading cause of food-borne illness, little is known about the mechanisms by which this pathogen mediates prolonged environmental survival or host cell virulence. Although these behaviours represent distinct phenotypes, they share a common requirement of an immobilized state. In order to understand the cellular mechanisms that facilitate a surface-associated lifestyle, transcriptional and translational expression profiles were determined for sessile and planktonic C. jejuni. These investigations indicate that the immobilized bacteria undergo a shift in cellular priorities away from metabolic, motility and protein synthesis capabilities towards emphasis on iron uptake, oxidative stress defence and membrane transport. This pattern of expression partially overlaps those reported for Campylobacter during host colonization, as well as for other species of bacteria involved in biofilms, highlighting common adaptive responses to the conserved challenges within each of these phenotypes. The adaptation of Campylobacter to immobilized growth may represent a quasi-differentiated state that functions as a foundation for further specialization towards phenotypes such as biofilm formation or host cell virulence.

Cofacial Heme Binding is Linked to Dimerization by a Bacterial Heme Transport Protein

“…In contrast to PhuW knockouts, mutants of chuB, chuC, or chuD, which encode the periplasmic and inner-membrane components of the transport system, exhibited no obvious phenotype. Global analyses of expression during iron-restricted, 7,10 immobilized, 20 and intestinal 21 growth reveal similar expression patterns for the chuA and chaR outermembrane receptors, suggesting that these two heme uptake systems may function synergistically. The need for multiple heme uptake systems may reflect the diversity of heme protein sources.…”

Autoinducer-2 Triggers the Oxidative Stress Response in Mycobacterium avium , Leading to Biofilm Formation

“…A study by Seib et al (43) shows that OxyR is necessary for biofilm formation in Neisseria gonorrhoeae. The link between biofilm formation and oxidative stress has been shown in a number of bacteria, including E. coli (42), Helicobacter influenzae (32), Campylobacter jejuni (41), and Streptococcus mutans (55). These examples show that biofilm formation can be linked to oxidative stress as a reaction to changing environmental conditions.…”

Iron-withholding strategy in innate immunity

“…Parent et al (2002) Campylobacter jejuni Both proteomic and microarray data showed significant upregulation of proteins and genes with involvement in iron acquisition. Sampathkumar et al (2006) Upregulation of all of the proposed iron-transport systems for hemin, ferric iron and enterochelin, as well as putative iron transport genes under iron-limited conditions.…”