title: Nutrient shock and incubation atmosphere influence recovery of culturable Helicobacter pylori from water.
abstract: Three different media-Columbia agar, Wilkins-Chalgren agar, and Helicobacter pylori special peptone agar-were prepared in a diluted version and compared to the standard medium formulation in order to study a possible nutrient shock effect observed when recovering H. pylori from water by counting the number of CFU. This same parameter was subsequently used to evaluate the influence of the incubation atmosphere by using a modular atmosphere-controlled system to provide different atmospheres and by employing an established gas generation kit as a control. Both a low nutrient content of the media and a rapidly achieved microaerophilic incubation atmosphere proved to increase the numbers of environment-stressed H. pylori organisms recovered. An atmosphere of 5% CO(2), 5% O(2), and 3% H(2) is recommended, although other atmospheres with a low oxygen concentration are also acceptable. Besides highlighting and assessing the importance of several factors in the culturability of H. pylori, this paper demonstrates the potential ability to develop an optimized technique for recovery of this pathogen from water.
authors.affiliation: Centro de Engenharia Biológica, Universidade do Minho, 4700-057 Braga, Portugal.
authors.forename: N F
authors.initials: NF
authors.lastname: Azevedo
authors.forename: A P
authors.initials: AP
authors.lastname: Pacheco
authors.forename: C W
authors.initials: CW
authors.lastname: Keevil
authors.forename: M J
authors.initials: MJ
authors.lastname: Vieira
mesh_terms: D001431:Bacteriological Techniques; D002245:Carbon Dioxide / Q000494:pharmacology; D015169:Colony Count, Microbial; D003470:Culture Media; D005740:Gases / Q000494:pharmacology*; D018869:Heat-Shock Response; D016480:Helicobacter pylori / Q000254:growth & development* / Q000502:physiology*; D006859:Hydrogen / Q000494:pharmacology; D010100:Oxygen / Q000494:pharmacology; D014871:Water Microbiology
chemical_list: D003470:Culture Media; D005740:Gases; D002245:Carbon Dioxide; D006859:Hydrogen; D010100:Oxygen