title: A standardized mouse model of Helicobacter pylori infection: introducing the Sydney strain.
abstract: OBJECTIVE
  Currently available Helicobacter pylori models show variable and, in some instances, poor colonization. There is a need for a strain with high colonizing ability to act as a standard for animal studies.
  
  
  METHODS
  After screening a range of fresh clinical isolates and long-term adaptation in mice, a strain of H. pylon has been isolated with a very good colonizing ability.
  
  
  RESULTS
  This strain, named the Sydney strain of H. pylori (strain SS1), is cagA and vacA positive. High levels of colonization (10(6)-10(7) colony-forming units/g tissue) were achieved consistently in C57BL/6 mice. Colonization levels varied depending on the mouse strain used with BALB/c, DBA/2, and C3H/He, all being colonized but in lower numbers. In all strains of mice, bacteria were clearly visible at the junctional zone between the antrum and the body. The phenotype was stable with colonizing ability remaining after 20 subcultures in vitro. The bacterium attached firmly to gastric epithelium. During 8 months, a chronic active gastritis slowly developed, progressing to severe atrophy in both C57BL/6 and BALB/c mice.
  
  
  CONCLUSIONS
  The Sydney strain of H. pylori is available to all and will provide a standardized mouse model for vaccine development, compound screening, and studies in pathogenesis.
authors.affiliation: School of Microbiology and Immunology, The University of New South Wales, Sydney, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: O'Rourke
authors.forename: M C
authors.initials: MC
authors.lastname: De Ungria
authors.forename: B
authors.initials: B
authors.lastname: Robertson
authors.forename: G
authors.initials: G
authors.lastname: Daskalopoulos
authors.forename: M F
authors.initials: MF
authors.lastname: Dixon
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001422:Bacterial Adhesion / Q000502:physiology; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D005260:Female; D016481:Helicobacter Infections / Q000382:microbiology* / Q000473:pathology*; D016480:Helicobacter pylori / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008854:Microscopy, Electron; D013045:Species Specificity; D013270:Stomach / Q000382:microbiology / Q000473:pathology
chemical_list: D000900:Anti-Bacterial Agents