Polar localization of CheO under hypoxia promotes Campylobacter jejuni chemotactic behavior within host

Abstract

Campylobacter jejuni is a food-borne zoonotic pathogen of worldwide concern and the leading cause of bacterial diarrheal disease. In contrast to other enteric pathogens, C. jejuni has strict growth and nutritional requirements but lacks many virulence factors that have evolved for pathogenesis or interactions with the host. It is unclear how this bacterium has adapted to an enteric lifestyle. Here, we discovered that the CheO protein (CJJ81176_1265) is required for C. jejuni colonization of mice gut through its role in chemotactic control of flagellar rotation in oxygen-limiting environments. CheO interacts with the chemotaxis signaling proteins CheA and CheZ, and also with the flagellar rotor components FliM and FliY. Under microaerobic conditions, CheO localizes at the cellular poles where the chemosensory array and flagellar machinery are located in C. jejuni and its polar localization depends on chemosensory array formation. Several chemoreceptors that mediate energy taxis coordinately determine the bipolar distribution of CheO. Suppressor screening for a ΔcheO mutant identified that a single residue variation in FliM can alleviate the phenotype caused by the absence of CheO, confirming its regulatory role in the flagellar rotor switch. CheO homologs are only found in species of the Campylobacterota phylum, mostly species of host-associated genera Campylobacter, Helicobacter and Wolinella. The CheO results provide insights into the complexity of chemotaxis signal transduction in C. jejuni and closely related species. Importantly, the recruitment of CheO into chemosensory array to promote chemotactic behavior under hypoxia represents a new adaptation strategy of C. jejuni to human and animal intestines.

Microbial Metabolite Trimethylamine N-Oxide PromotesCampylobacter jejuniInfection by Escalating Intestinal Inflammation, Epithelial Damage, and Barrier Disruption

“…In addition to the vehicle control and serine, a known chemoattractant for C. jejuni 31,63,64 , we examined TMAO, as well as other precursor molecules of TMA, including L-carnitine and betaine, found in red meat and proteinaceous leafy greens, respectively 37,65 . After 24 hours of incubation under microaerobic conditions, the zones were measured according to Mo et al 66,67 . We found that, in comparison with vehicle control, TMAO and its precursor molecules, including L-carnitine and betaine, promoted chemotaxis statistically similar to serine, a known strong chemoattractant 68 for C. jejuni (Fig.…”

Disulfiram with Cu2+ alleviates dextran sulfate sodium-induced ulcerative colitis in mice

“…Both animal and clinical trials have reported that Bifidobacterium longum could reduce chronic mucosal inflammation in UC patients and prevent the occurrence of experimental colitis induced by DSS 39 , 40 . Campylobacter, a zoonotic pathogen, is the leading cause of human bacterial enteritis 41 and Helicobacter has been recognized as a major risk factor for gastritis, peptic ulcers, gastric cancer, and gastric mucous-associated lymphoma 42 , 43 . Our data suggested that DSS induction increased harmful bacteria in the gut, but DSF+Cu 2+ treatment increased beneficial gut bacteria.…”