Phospholipase C activity of Helicobacter pylori is not associated with the presence of the cagA gene.

ABSTRACT

BACKGROUND: Knowledge about the possible role of phospholipase C (PLC) activity of microbial pathogens in the development of disease is increasing. Recently attention has focused on investigating PLC activity elaborated by Helicobacter pylori, but the role of this enzyme in H. pylori pathogenesis is still unknown. The aim of this study was to correlate PLC-activity of H. pylori on the basis of the cagA status with the clinical diagnosis of the patients. MATERIALS AND METHODS: Helicobacter pylori was isolated from patients with gastritis (G; n = 38), duodenal ulcer (DU; n = 15), gastric ulcer (GU; n = 11) and gastric cancer (GC; n = 12). Polymerase chain reaction primers DZ3/R009 which amplified a 1350-bp fragment were used to detect the cagA gene. PLC activity was determined using p-nitrophenylphosphorylcholine as substrate. RESULTS: Of the strains, 60% were cagA(+) and 40% were cagA(-). All strains showed PLC activity (2.20 +/- 0.91 U mg(-1) protein). PLC activity showed no association with the cagA status cagA(+) (2.21 +/- 1.03 U mg(-1) protein), cagA(-) (2.18 +/- 0.79 U mg(-1) protein). Patients with GU had the highest PLC activity (2.77 +/- 1.26 U mg(-1) protein) and patients with GC had the lowest activity (1.8 +/- 0.57 U mg(-1) protein). CONCLUSIONS: Although PLC activity was present in all strains tested, it may only have pathological importance in patients with GU. However, the extent of PLC activity was independent of the presence of the cagA gene.