title: TheCampylobacter jejuniOxidative Stress Regulator RrpB Is Associated with a Genomic Hypervariable Region and Altered Oxidative Stress Resistance.
abstract: Campylobacter jejuniis the leading cause of bacterial foodborne diarrhoeal disease worldwide. Despite the microaerophilic nature of the bacterium,C. jejunican survive the atmospheric oxygen conditions in the environment. Bacteria that can survive either within a host or in the environment likeC. jejunirequire variable responses to survive the stresses associated with exposure to different levels of reactive oxygen species. The MarR-type transcriptional regulators RrpA and RrpB have recently been shown to play a role in controlling both theC. jejunioxidative and aerobic stress responses. Analysis of 3,746C. jejuniand 486C. coligenome sequences showed that whilstrrpAis present in over 99% ofC. jejunistrains, the presence ofrrpBis restricted and appears to correlate with specific MLST clonal complexes (predominantly ST-21 and ST-61).C. colistrains in contrast lack bothrrpAandrrpB. InC. jejuni rrpB+strains, therrpBgene is located within a variable genomic region containing the IF subtype of the type I Restriction-Modification (hsd) system, whilst this variable genomic region inC. jejuni rrpB-strains contains the IAB subtypehsdsystem and not therrpBgene.C. jejuni rrpB-strains exhibit greater resistance to peroxide and aerobic stress thanC. jejuni rrpB+strains. Inactivation ofrrpAresulted in increased sensitivity to peroxide stress inrrpB+strains, but not inrrpB-strains. Mutation ofrrpAresulted in reduced killing ofGalleria mellonellalarvae and enhanced biofilm formation independent ofrrpBstatus. The oxidative and aerobic stress responses ofrrpB-andrrpB+strains suggest adaptation ofC. jejuniwithin different hosts and niches that can be linked to specific MLST clonal complexes.
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, UK.
authors.forename: Ozan
authors.initials: O
authors.lastname: Gundogdu
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, UK.
authors.forename: Daiani T
authors.initials: DT
authors.lastname: da Silva
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, UK.
authors.forename: Banaz
authors.initials: B
authors.lastname: Mohammad
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, UK.
authors.forename: Abdi
authors.initials: A
authors.lastname: Elmi
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, UK.
authors.forename: Brendan W
authors.initials: BW
authors.lastname: Wren
authors.affiliation: School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey Guildford, UK.
authors.forename: Arnoud H M
authors.initials: AH
authors.lastname: van Vliet
authors.affiliation: Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine London, UK.
authors.forename: Nick
authors.initials: N
authors.lastname: Dorrell
keywords: Campylobacter jejuni oxidative stress response regulation; aerobic stress response regulation; restriction modification system; transcription factors