title: Salmonella Enteritidis flagellar mutants have a colonization benefit in the chicken oviduct.
abstract: Egg borne Salmonella Enteritidis is still a major cause of human food poisoning. Eggs can become internally contaminated following colonization of the hen's oviduct. In this paper we aimed to analyze the role of flagella of Salmonella Enteritidis in colonization of the hen's oviduct. Using a transposon library screen we showed that mutants lacking functional flagella are significantly more efficient in colonizing the hen's oviduct in vivo. A micro-array analysis proved that transcription of a number of flagellar genes is down-regulated inside chicken oviduct cells. Flagella contain flagellin, a pathogen associated molecular pattern known to bind to Toll-like receptor 5, activating a pro-inflammatory cascade. In vitro tests using primary oviduct cells showed that flagellin is not involved in invasion. Using a ligated loop model, a diminished inflammatory reaction was seen in the oviduct resulting from injection of an aflagellated mutant compared to the wild-type. It is hypothesized that Salmonella Enteritidis downregulates flagellar gene expression in the oviduct and consequently prevents a flagellin-induced inflammatory response, thereby increasing its oviduct colonization efficiency.
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium. Electronic address: Sofie.Kilroy@ugent.be.
authors.forename: Sofie
authors.initials: S
authors.lastname: Kilroy
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium. Electronic address: r.raspoet@phileo.lesaffre.com.
authors.forename: Ruth
authors.initials: R
authors.lastname: Raspoet
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium. Electronic address: An.Martel@ugent.be.
authors.forename: An
authors.initials: A
authors.lastname: Martel
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium. Electronic address: Leslie.Bosseler@ugent.be.
authors.forename: Leslie
authors.initials: L
authors.lastname: Bosseler
authors.affiliation: John Innes Centre, Norwich Research Park, Colney Ln, Norwich NR4 7UH, Norwich, United Kingdom; Institute of Food Research, Norwich Research Park, Colney Ln, Norwich NR4 7UA, United Kingdom. Electronic address: Corinne.Appia-Ayme@jic.ac.uk.
authors.forename: Corinne
authors.initials: C
authors.lastname: Appia-Ayme
authors.affiliation: Institute of Food Research, Norwich Research Park, Colney Ln, Norwich NR4 7UA, United Kingdom. Electronic address: Arthur.Thompson@ifr.ac.uk.
authors.forename: Arthur
authors.initials: A
authors.lastname: Thompson
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium. Electronic address: Freddy.Haesebrouck@ugent.be.
authors.forename: Freddy
authors.initials: F
authors.lastname: Haesebrouck
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium. Electronic address: Richard.Ducatelle@ugent.be.
authors.forename: Richard
authors.initials: R
authors.lastname: Ducatelle
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, B-9820 Merelbeke, Belgium. Electronic address: Filip.VanImmerseel@ugent.be.
authors.forename: Filip
authors.initials: F
authors.lastname: Van Immerseel
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion; D002478:Cells, Cultured; D002645:Chickens; D004251:DNA Transposable Elements; D015536:Down-Regulation; D004847:Epithelial Cells / Q000382:microbiology; D005260:Female; D005407:Flagella / Q000235:genetics*; D005408:Flagellin / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015723:Gene Library; D006801:Humans; D007249:Inflammation; D009154:Mutation; D010057:Oviducts / Q000166:cytology / Q000276:immunology / Q000382:microbiology*; D011201:Poultry Diseases / Q000382:microbiology; D012481:Salmonella Infections, Animal / Q000382:microbiology; D012477:Salmonella enteritidis / Q000235:genetics* / Q000254:growth & development* / Q000502:physiology
chemical_list: D004251:DNA Transposable Elements; D005408:Flagellin
keywords: Enteritidis; Flagellin; Laying hen; Oviduct; Salmonella