title: Description of 'Candidatus Helicobacter heilmannii' based on DNA sequence analysis of 16S rRNA and urease genes.
abstract: While Helicobacter pylori is accepted as the major bacterial agent of gastric disease in humans, some patients and many animals are infected with a larger, tightly helical-shaped bacterium previously referred to as 'Helicobacter heilmannii' or 'Gastrospirillum hominis'. Taxonomic classification of these bacteria has been hampered by the inability to cultivate them in vitro and by the inadequate discriminatory power of 16S rRNA gene sequence analysis. This study describes the detection and phylogenetic analysis of 26 different gastrospirillum isolates from humans and animals, which incorporates sequence data based on the 16S rRNA and urease genes. Fifteen gastrospirilla detected in humans, primates and pigs clustered with 'Candidatus Helicobacter suis', thus expanding the host range for this organism. By comparison, based on 16S rRNA data, the remaining 11 gastrospirilla could not be differentiated from Helicobacter felis, Helicobacter bizzozeronii and Helicobacter salomonis. However, urease gene sequence analysis allowed for the discrimination of this latter group into four discrete clusters, three of which contained the above recognized species. The fourth cluster contained isolates from human and feline hosts, and should provisionally be considered a unique bacterial species, for which the name 'Candidatus Helicobacter heilmannii' is proposed.
authors.affiliation: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia, 2052.
authors.forename: Jani L
authors.initials: JL
authors.lastname: O'Rourke
authors.affiliation: Departments of Internal Medicine and Medical Microbiology & Immunology, The Center for Comparative Medicine, University of California, Davis, CA 95616-8645, USA.
authors.forename: Jay V
authors.initials: JV
authors.lastname: Solnick
authors.affiliation: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia, 2052.
authors.forename: Brett A
authors.initials: BA
authors.lastname: Neilan
authors.affiliation: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia, 2052.
authors.forename: Karin
authors.initials: K
authors.lastname: Seidel
authors.affiliation: Departments of Internal Medicine and Medical Microbiology & Immunology, The Center for Comparative Medicine, University of California, Davis, CA 95616-8645, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Hayter
authors.affiliation: Departments of Internal Medicine and Medical Microbiology & Immunology, The Center for Comparative Medicine, University of California, Davis, CA 95616-8645, USA.
authors.forename: Lori M
authors.initials: LM
authors.lastname: Hansen
authors.affiliation: School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia, 2052.
authors.forename: Adrian
authors.initials: A
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000737:chemistry / Q000302:isolation & purification; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology; D005773:Gastroscopy; D020459:Genes, rRNA; D016998:Helicobacter / Q000145:classification* / Q000235:genetics; D016481:Helicobacter Infections / Q000382:microbiology / Q000662:veterinary; D018247:Helicobacter heilmannii / Q000145:classification* / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D010802:Phylogeny; D011323:Primates / Q000382:microbiology; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013552:Swine / Q000382:microbiology; D014510:Urease / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D014510:Urease