title: Maintenance of Helicobacter pylori cultures in agar stabs.
abstract: BACKGROUND
  Helicobacter pylori requires frequent passage at 37 °C with reduced oxygen tension to maintain viability, and recovery from frozen stocks can be unpredictable and slow. Agar stab cultures were assessed as a possible means of maintaining viability without the need to passage every 4-7 days.
  
  
  METHODS
  Agar stabs prepared from either Brucella or Brain Heart Infusion media were inoculated deeply with H. pylori strains or H. felis and grown under varying conditions for up to 13 weeks. Subcultures were prepared from these stabs at various intervals to test for viability.
  
  
  RESULTS
  Established cultures in agar stabs failed to survive at room temperature but did survive at 37 °C with 10% CO₂ for up to 56 days. H. felis remained viable for up to 28 days. No difference was observed between the two media formulations.
  
  
  CONCLUSIONS
  H. pylori grown in agar stabs remains viable for prolonged periods of time without the need to subculture and may represent an improved method for storing H. pylori for infrequent use.
authors.affiliation: Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
authors.forename: Jinghua
authors.initials: J
authors.lastname: Xu
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Czinn
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Blanchard
mesh_terms: D000362:Agar; D001431:Bacteriological Techniques / Q000379:methods*; D003470:Culture Media / Q000737:chemistry; D044922:Helicobacter felis / Q000502:physiology; D016480:Helicobacter pylori / Q000502:physiology*; D050296:Microbial Viability; D011309:Preservation, Biological / Q000379:methods*; D013696:Temperature; D013997:Time Factors
chemical_list: D003470:Culture Media; D000362:Agar