Abstract
The Helicobacter pylori pathogenicity depends on the virulence factors and their interplay with the host. Gastric juice contains proteolytic enzymes; however, there is a lack of data to indicate their possible interaction with H. pylori virulence genes. To investigate the effect of pepsin on the pathogenicity of H. pylori, clinical isolates of H. pylori were provided and strains with ureB+/flaA+/cagA+ genotype were selected for the in vitro transcriptional analysis. Relative change in transcription of ureB, flaA and cagA genes was measured after treatment with pepsin at 0.5 and 1 mg/mL concentration for 30 and 90 min using real-time PCR. A diversity in the H. pylori isolates was detected for the carriage of ureB (100%), flaA (94.1%), and cagA (82.3%) genes. The transcriptional analysis showed down-regulation of ureB and flaA (0.2 to 0.008-fold) and up-regulation of cagA (3 to 9-fold) after the treatment. No significant diversity in transcriptional levels was detected in response to different concentrations of pepsin. In conclusion, our study confirmed the effect of pepsin at its normal concentration in gastric juice on the transcription of H. pylori virulence genes. Further studies are needed to show possible outcomes of this interplay on the pathogenesis.