title: Inactivation of the LysR regulator Cj1000 of Campylobacter jejuni affects host colonization and respiration.
abstract: Transcriptional regulation mediates adaptation of pathogens to environmental stimuli and is important for host colonization. The Campylobacter jejuni genome sequence reveals a surprisingly small set of regulators, mostly of unknown function, suggesting an intricate regulatory network. Interestingly, C. jejuni lacks the homologues of ubiquitous regulators involved in stress response found in many other Gram-negative bacteria. Nonetheless, cj1000 is predicted to encode the sole LysR-type regulator in the C. jejuni genome, and thus may be involved in major adaptation pathways. A cj1000 mutant strain was constructed and found to be attenuated in its ability to colonize 1-day-old chicks. Complementation of the cj1000 mutation restored the colonization ability to wild-type levels. The mutant strain was also outcompeted in a competitive colonization assay of the piglet intestine. Oxygraphy was carried out for what is believed to be the first time with the Oroboros Oxygraph-2k on C. jejuni and revealed a role for Cj1000 in controlling O2 consumption. Furthermore, microarray analysis of the cj1000 mutant revealed both direct and indirect regulatory targets, including genes involved in energy metabolism and oxidative stress defences. These results highlight the importance of Cj1000 regulation in host colonization and in major physiological pathways.
authors.affiliation: EA1254 Risques Infectieux, University of Rennes 1, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Dufour
authors.affiliation: Department of Biochemistry, Immunology and Microbiology, Ottawa Institute of Systems Biology, University of Ottawa, ON, Canada.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Li
authors.affiliation: Department of Biochemistry, Immunology and Microbiology, Ottawa Institute of Systems Biology, University of Ottawa, ON, Canada.
authors.forename: Annika
authors.initials: A
authors.lastname: Flint
authors.affiliation: UMR CNRS 7266 LIENSs, La Rochelle, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Rosenfeld
authors.affiliation: Anses, Unit HQPAP, Ploufragan, France.
authors.forename: Katell
authors.initials: K
authors.lastname: Rivoal
authors.affiliation: UMR CNRS 6026 DUALS, University of Rennes 1, France.
authors.forename: Sylvie
authors.initials: S
authors.lastname: Georgeault
authors.affiliation: UMR CNRS 6026 DUALS, University of Rennes 1, France.
authors.forename: Bachar
authors.initials: B
authors.lastname: Alazzam
authors.affiliation: UMR CNRS 6026 DUALS, University of Rennes 1, France.
authors.forename: Gwennola
authors.initials: G
authors.lastname: Ermel
authors.affiliation: Department of Biochemistry, Immunology and Microbiology, Ottawa Institute of Systems Biology, University of Ottawa, ON, Canada.
authors.forename: Alain
authors.initials: A
authors.lastname: Stintzi
authors.affiliation: EA1254 Risques Infectieux, University of Rennes 1, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Bonnaure-Mallet
authors.affiliation: EA1254 Risques Infectieux, University of Rennes 1, France.
authors.forename: Christine
authors.initials: C
authors.lastname: Baysse
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002169:Campylobacter Infections / Q000382:microbiology; D016123:Campylobacter jejuni / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity*; D002645:Chickens; D004195:Disease Models, Animal; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D055786:Gene Knockout Techniques; D005816:Genetic Complementation Test; D007422:Intestines / Q000382:microbiology; D053858:Metabolic Networks and Pathways / Q000235:genetics; D046228:Microarray Analysis; D010101:Oxygen Consumption; D013552:Swine; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D014157:Transcription Factors; C073470:LysR protein, Bacteria