Isolation of Helicobacter pylori strains and analysis of CYP2C19 genetic polymorphisms with the same gastric biopsy samples

Abstract

Objective To analyze the CYP2C19 genetic polymorphisms in patients suffering from gastric diseases in Beijing and Shandong, and to evaluate the possibility of using the same gastric biopsy samples for the isolation of Helicobacter pylori (H.pylori) strains. Methods A total of 1649 gastric biopsy samples positive for rapid urease test (RUT) were collected from patients with gastric diseases in Beijing and Shandong. Each sample was grinded and equally divided into two parts for the isolation of H. pylori strains and the analysis of CYP2C19 genetic polymorphisms, respectively. H. pylori strains were isolated from the samples and identified with catalase and urease. CYP2C19*2 and CYP2C19*3 specific primers were used for the PCR amplification of DNA extracts. The PCR products were analyzed by electrophoresis and nucleotide sequencing. The metabolic types of CYP2C19 were analyzed based on the results of nucleotide sequencing. Results Altogether 1415 (85.81%) H. pylori strains were isolated successfully from the 1649 gastric biopsy samples. The products of CYP2C19 specific PCR for all DNA extracts showed clear bands in electrophoresis and were further confirmed with sequencing analysis. Statistical analysis revealed that there were no statistical differences with the percentages of CYP2C19 metabolic types between Beijing and Shandong, nor between males and females (P>0.05). Conclusion It showed the possibility of using the same gastric biopsy samples for the isolation of H. pylori strains and the analysis of CYP2C19 genetic polymorphisms. No significant differences with the percentages of CYP2C19 metabolic types were found between patients from Beijing and Shandong. Key words: Gastric biopsy; Helicobacter pylori; CYP2C19; Genetic polymorphisms