title: High relative content of lysophospholipids of Helicobacter pylori mediates increased risk for ulcer disease.
abstract: Helicobacter pylori phospholipase A (OMPLA) degrades bacterial membrane phospholipids to lysophospholipids. High levels of lysophospholipids are associated with higher hemolytic activity, increased release of urease and vacA and better adherence to epithelial cells in vitro. The phospholipase A gene (pldA) displays phase variation due to a slippage in a homopolymeric tract. The aim of this study was to determine if the relative amount of lysophospholipids in the cell wall is associated with ulcer disease, and to further investigate the significance of pldA phase variation. H. pylori isolates of 40 patients were examined. The relative lysophospholipid content of each isolate was determined and the pldA gene was sequenced. The study indicated that H. pylori can regulate its OMPLA activity by phase variation in the pldA gene or by protein level regulation among phase variants in the pldA 'ON' status. We found a significant difference between the relative amount of lysophospholipids of the ulcer group and the non-ulcer group (p=0.022). When the lysophospholipid/phospholipid ratios were compared with outcome, the OR for ulcer disease was 9.0 (95% CI 1.6-49.4; p=0.014). Isolates with a high OMPLA activity are significantly associated with patients with ulcer disease.
authors.affiliation: Institute of Clinical Epidemiology and Molecular Biology, University of Oslo, Oslo, Norway.
authors.forename: Tone
authors.initials: T
authors.lastname: Tannaes
authors.forename: Ida K
authors.initials: IK
authors.lastname: Bukholm
authors.forename: Geir
authors.initials: G
authors.lastname: Bukholm
mesh_terms: D001483:Base Sequence; D004269:DNA, Bacterial / Q000235:genetics; D004381:Duodenal Ulcer / Q000209:etiology* / Q000382:microbiology; D005798:Genes, Bacterial; D014644:Genetic Variation; D005838:Genotype; D016481:Helicobacter Infections / Q000209:etiology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000235:genetics / Q000378:metabolism* / Q000472:pathogenicity*; D006801:Humans; D008246:Lysophospholipids / Q000737:chemistry / Q000378:metabolism*; D010741:Phospholipases A / Q000235:genetics / Q000378:metabolism; D011110:Polymorphism, Genetic; D012307:Risk Factors; D013276:Stomach Ulcer / Q000209:etiology* / Q000382:microbiology; D014774:Virulence / Q000235:genetics / Q000502:physiology
chemical_list: D004269:DNA, Bacterial; D008246:Lysophospholipids; D010741:Phospholipases A