title: A novel enterohepatic Helicobacter species 'Helicobacter mastomyrinus' isolated from the liver and intestine of rodents.
abstract: BACKGROUND
  A number of novel Helicobacter species have been isolated from both animals and humans. Many of these helicobacters colonize the lower gastrointestinal tract and hepatobiliary tract and are associated with diseases.
  
  
  METHODS
  A spiral-shaped bacterium, with bipolar single-sheathed flagella, was isolated from the liver and cecum of mastomys (the African rodent, Mastomys natalenis), from the feces and ceca of normal mice, and also from the cecum of a mouse with proctitis. 16S ribosomal RNA gene sequence analysis, restriction fragment length polymorphism (RFLP) and fluorophore-enhanced repetitive element polymerase chain reaction (FERP or rep-PCR) analysis were used to classify the organism.
  
  
  RESULTS
  The bacterium grew at 37 and 42 degrees C under microaerobic conditions, rapidly hydrolyzed urea, and was catalase and oxidase positive. It did not reduce nitrate to nitrite, and was resistant to cephalothin and nalidixic acid. Like many other enterohepatic Helicobacter species, this organism expressed cytolethal distending toxin and causes cell distention.
  
  
  CONCLUSIONS
  The organism was classified as a novel Helicobacter species for which we propose the name 'Helicobacter mastomyrinus'. Although 'H. mastomyrinus', like Helicobacter hepaticus and Helicobacter bilis, colonizes the liver of rodents, the pathogenic potential of this novel helicobacter is unknown.
authors.affiliation: Division of Comparative Medicine, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
authors.forename: Zeli
authors.initials: Z
authors.lastname: Shen
authors.forename: Shilu
authors.initials: S
authors.lastname: Xu
authors.forename: Floyd E
authors.initials: FE
authors.lastname: Dewhirst
authors.forename: Bruce J
authors.initials: BJ
authors.lastname: Paster
authors.forename: Jeremy A
authors.initials: JA
authors.lastname: Pena
authors.forename: Irvin M
authors.initials: IM
authors.lastname: Modlin
authors.forename: Mark
authors.initials: M
authors.lastname: Kidd
authors.forename: James G
authors.initials: JG
authors.lastname: Fox
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000032:analysis; D015373:Bacterial Typing Techniques; D002432:Cecum / Q000382:microbiology; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D004275:DNA, Ribosomal / Q000737:chemistry / Q000302:isolation & purification; D005243:Feces / Q000382:microbiology; D005260:Female; D020459:Genes, rRNA; D016998:Helicobacter / Q000145:classification* / Q000302:isolation & purification* / Q000502:physiology / Q000648:ultrastructure; D016481:Helicobacter Infections / Q000382:microbiology / Q000473:pathology / Q000662:veterinary*; D007422:Intestines / Q000382:microbiology*; D008099:Liver / Q000382:microbiology*; D051379:Mice; D008969:Molecular Sequence Data; D009115:Muridae; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D012329:RNA, Bacterial / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012376:Rodent Diseases / Q000382:microbiology* / Q000473:pathology; D017422:Sequence Analysis, DNA; D014508:Urea / Q000378:metabolism
chemical_list: D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D014508:Urea