title: Divergence between the Highly Virulent Zoonotic Pathogen Helicobacter heilmannii and Its Closest Relative, the Low-Virulence "Helicobacter ailurogastricus" sp. nov.
abstract: Helicobacter heilmannii naturally colonizes the stomachs of dogs and cats and has been associated with gastric disorders in humans. Nine feline Helicobacter strains, classified as H. heilmannii based on ureAB and 16S rRNA gene sequences, were divided into a highly virulent and a low-virulence group. The genomes of these strains were sequenced to investigate their phylogenetic relationships, to define their gene content and diversity, and to determine if the differences in pathogenicity were associated with the presence or absence of potential virulence genes. The capacities of these helicobacters to bind to the gastric mucosa were investigated as well. Our analyses revealed that the low-virulence strains do not belong to the species H. heilmannii but to a novel, closely related species for which we propose the name Helicobacter ailurogastricus. Several homologs of H. pylori virulence factors, such as IceA1, HrgA, and jhp0562-like glycosyltransferase, are present in H. heilmannii but absent in H. ailurogastricus. Both species contain a VacA-like autotransporter, for which the passenger domain is remarkably larger in H. ailurogastricus than in H. heilmannii. In addition, H. ailurogastricus shows clear differences in binding to the gastric mucosa compared to H. heilmannii. These findings highlight the low-virulence character of this novel Helicobacter species.
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Myrthe
authors.initials: M
authors.lastname: Joosten
authors.affiliation: Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Sara
authors.initials: S
authors.lastname: Lindén
authors.affiliation: Department of Food Hygiene and Environmental Health, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
authors.forename: Mirko
authors.initials: M
authors.lastname: Rossi
authors.affiliation: The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Nedlands, Perth, Western Australia, Australia.
authors.forename: Alfred Chin Yen
authors.identifier: http://orcid.org/0000-0001-9705-4010
authors.initials: AC
authors.lastname: Tay
authors.affiliation: Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Emma
authors.initials: E
authors.lastname: Skoog
authors.affiliation: Department of Medical Biochemistry and Cell Biology, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
authors.forename: Médea
authors.initials: M
authors.lastname: Padra
authors.affiliation: The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Nedlands, Perth, Western Australia, Australia.
authors.forename: Fanny
authors.initials: F
authors.lastname: Peters
authors.affiliation: The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Nedlands, Perth, Western Australia, Australia.
authors.forename: Tim
authors.initials: T
authors.lastname: Perkins
authors.affiliation: Department of Biochemistry and Microbiology, Faculty of Sciences, Ghent University, Ghent, Belgium.
authors.forename: Peter
authors.initials: P
authors.lastname: Vandamme
authors.affiliation: Laboratory of Pharmaceutical Biotechnology, Ghent University, Ghent, Belgium.
authors.forename: Filip
authors.initials: F
authors.lastname: Van Nieuwerburgh
authors.affiliation: Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium.
authors.forename: Katharina
authors.initials: K
authors.lastname: D'Herde
authors.affiliation: Department of Morphology, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Van den Broeck
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Bram
authors.initials: B
authors.lastname: Flahou
authors.affiliation: Laboratory of Pharmaceutical Biotechnology, Ghent University, Ghent, Belgium.
authors.forename: Dieter
authors.initials: D
authors.lastname: Deforce
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Richard
authors.initials: R
authors.lastname: Ducatelle
authors.affiliation: The Marshall Centre for Infectious Diseases Research and Training, University of Western Australia, Nedlands, Perth, Western Australia, Australia.
authors.forename: Barry
authors.initials: B
authors.lastname: Marshall
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium.
authors.forename: Freddy
authors.initials: F
authors.lastname: Haesebrouck
authors.affiliation: Department of Pathology, Bacteriology and Avian Diseases, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium Annemieke.Smet@UGent.be.
authors.forename: Annemieke
authors.initials: A
authors.lastname: Smet
mesh_terms: D000818:Animals; D001422:Bacterial Adhesion / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D002415:Cats; D002460:Cell Line; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics; D004285:Dogs; D004847:Epithelial Cells / Q000382:microbiology; D005753:Gastric Mucosa / Q000166:cytology / Q000382:microbiology*; D005756:Gastritis / Q000382:microbiology*; D005849:Gerbillinae; D016695:Glycosyltransferases / Q000235:genetics; D016481:Helicobacter Infections / Q000382:microbiology; D018247:Helicobacter heilmannii / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity*; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology / Q000382:microbiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D014774:Virulence / Q000235:genetics; D015047:Zoonoses / Q000382:microbiology
chemical_list: D001426:Bacterial Proteins; D012336:RNA, Ribosomal, 16S; C405087:iceA1 protein, Helicobacter pylori; D016695:Glycosyltransferases; D015252:Deoxyribonucleases, Type II Site-Specific; C470753:HrgA protein, Helicobacter pylori