title: Genomic variations leading to alterations in cell morphology of Campylobacter spp.
abstract: Campylobacter jejuni, the most common cause of bacterial diarrhoeal disease, is normally helical. However, it can also adopt straight rod, elongated helical and coccoid forms. Studying how helical morphology is generated, and how it switches between its different forms, is an important objective for understanding this pathogen. Here, we aimed to determine the genetic factors involved in generating the helical shape of Campylobacter. A C. jejuni transposon (Tn) mutant library was screened for non-helical mutants with inconsistent results. Whole genome sequence variation and morphological trends within this Tn library, and in various C. jejuni wild type strains, were compared and correlated to detect genomic elements associated with helical and rod morphologies. All rod-shaped C. jejuni Tn mutants and all rod-shaped laboratory, clinical and environmental C. jejuni and Campylobacter coli contained genetic changes within the pgp1 or pgp2 genes, which encode peptidoglycan modifying enzymes. We therefore confirm the importance of Pgp1 and Pgp2 in the maintenance of helical shape and extended this to a wide range of C. jejuni and C. coli isolates. Genome sequence analysis revealed variation in the sequence and length of homopolymeric tracts found within these genes, providing a potential mechanism of phase variation of cell shape.
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
authors.forename: Diane
authors.initials: D
authors.lastname: Esson
authors.affiliation: Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.
authors.forename: Alison E
authors.initials: AE
authors.lastname: Mather
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
authors.forename: Eoin
authors.initials: E
authors.lastname: Scanlan
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
authors.forename: Srishti
authors.initials: S
authors.lastname: Gupta
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
authors.forename: Stefan P W
authors.initials: SP
authors.lastname: de Vries
authors.affiliation: Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, UK.
authors.forename: David
authors.initials: D
authors.lastname: Bailey
authors.affiliation: Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.
authors.forename: Simon R
authors.initials: SR
authors.lastname: Harris
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
authors.forename: Trevelyan J
authors.initials: TJ
authors.lastname: McKinley
authors.affiliation: The Milner Centre for Evolution, Department of Biology and Biotechnology, University of Bath, Claverton Down, Bath, UK.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Méric
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
authors.forename: Sophia K
authors.initials: SK
authors.lastname: Berry
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
authors.forename: Pietro
authors.initials: P
authors.lastname: Mastroeni
authors.affiliation: The Milner Centre for Evolution, Department of Biology and Biotechnology, University of Bath, Claverton Down, Bath, UK.
authors.forename: Samuel K
authors.initials: SK
authors.lastname: Sheppard
authors.affiliation: Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, UK.
authors.forename: Graham
authors.initials: G
authors.lastname: Christie
authors.affiliation: Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.|The London School of Hygiene and Tropical Medicine, London, UK.
authors.forename: Nicholas R
authors.initials: NR
authors.lastname: Thomson
authors.affiliation: Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK.
authors.forename: Julian
authors.initials: J
authors.lastname: Parkhill
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
authors.forename: Duncan J
authors.initials: DJ
authors.lastname: Maskell
authors.affiliation: Department of Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge, UK.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Grant
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002169:Campylobacter Infections / Q000382:microbiology / Q000662:veterinary*; D017000:Campylobacter coli / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D016123:Campylobacter jejuni / Q000235:genetics* / Q000378:metabolism / Q000648:ultrastructure; D002645:Chickens; D004251:DNA Transposable Elements; D015964:Gene Expression Regulation, Bacterial; D015723:Gene Library; D016680:Genome, Bacterial; D006801:Humans; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D010457:Peptidoglycan / Q000096:biosynthesis / Q000235:genetics; D011201:Poultry Diseases / Q000382:microbiology*; D000073336:Whole Genome Sequencing
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D010457:Peptidoglycan