Helicobacter pylori: characteristics, pathogenicity, detection methods andmode of transmission implicating foods and water

Helicobacter pylori is an organism involved in the pathogenesis of human ac tive chronic gastritis, peptic and duodenal ulcer diseases and gastric canc er. This review article covers this emerging human pathogen in terms of its phenotypic and genotypic characteristics, methods for culturing, its role in gastric pathogenicity, evidence involving its mode of transmission, diff iculty in its isolation and detection methodology. In terms of transmission , both foodborne and waterborne pathways have been speculated as the mode o f transmission for H. pylori as the patterns of the infection are consisten t with those from fecal-oral and oral-oral transmission. Therefore, it is i mportant to also evaluate methods for the detection of H. pylori from speci fically food products and water. The detection of this pathogen has proved difficult since changes in cell morphology, metabolism and growth patterns occur when H. pylori is exposed to different environmental stimuli. The dev elopment of a viable but non-culturable coccoid (VNC) form is observed. The se VNC forms do not undergo cellular division and cannot be cultured by tra ditional methods, increasing the difficulty in their detection. Since both viability and virulence in the VNC form of H. pylori are retained, the exam ination of food products and water for these forms is critical. Current met hods include filtration, immune-separation (IMS), polymerase chain reaction (PCR), probe hybridization, immune-staining, autoradiography and ATP biolu minescence. (C) 1999 Elsevier Science B.V. All rights reserved.