title: Cytolethal distending toxin: a potential virulence factor for Helicobacter cinaedi.
abstract: Although Helicobacter cinaedi is the most commonly reported enterohepatic helicobacter in humans, there are no reports of virulence factors, and little is known about how it infects and causes disease. In this study, H. cinaedi isolates from humans and animals were examined for production of cytolethal distending toxin (Cdt). Cdt causes distention in cells and arrest in the G2/M phase of cell division. It is encoded by three genes: cdtA, cdtB, and cdtC. cdtB is the most conserved. All isolates except the American Type Culture Collection strain (identified as H. fennelliae) demonstrated Cdt activity and had a cdtB polymerase chain-reaction product homologous with known cdtB. Deduced amino acid sequences of cdtB showed a high (93%-99%) degree of similarity among the H. cinaedi isolates. H. cinaedi shares the production of Cdt with other enteric pathogens, including enterohepatic Helicobacter species. This is the first report of a putative virulence factor in H. cinaedi.
authors.affiliation: Division of Comparative Medicine, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA. nstaylor@mit.edu
authors.forename: Nancy S
authors.initials: NS
authors.lastname: Taylor
authors.forename: Zhongming
authors.initials: Z
authors.lastname: Ge
authors.forename: Zeli
authors.initials: Z
authors.lastname: Shen
authors.forename: Floyd E
authors.initials: FE
authors.lastname: Dewhirst
authors.forename: James G
authors.initials: JG
authors.lastname: Fox
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001427:Bacterial Toxins / Q000096:biosynthesis / Q000235:genetics* / Q000494:pharmacology; D002453:Cell Cycle / Q000187:drug effects; D003001:Cloning, Molecular; D006367:HeLa Cells / Q000187:drug effects / Q000276:immunology / Q000473:pathology; D016998:Helicobacter / Q000302:isolation & purification / Q000472:pathogenicity*; D016481:Helicobacter Infections / Q000382:microbiology / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D016415:Sequence Alignment; D037521:Virulence Factors / Q000235:genetics* / Q000494:pharmacology
chemical_list: D001427:Bacterial Toxins; D012336:RNA, Ribosomal, 16S; D037521:Virulence Factors; C067044:cytolethal distending toxin