Detection and Analysis of Helicobacter pylori DNA in the Gastric Juice, Saliva, and Urine by Nested PCR

The aim of this study was to investigate the strain heterogeneity of Helicobacter pylori (H. pylori) in saliva, gastric juice, and urine by nested PCR and the direct sequence method, and to clarify the mode of transmission by examining whether H. pylori in the stomach and saliva are identical.Thirty-nine patients undergoing endoscopy were enrolled in this study. H. pylori DNA was assayed in 104 samples using two sets of primers, EHC-U/EHC-L and ET-5U/ET-5L. DNA sequencing was performed in 24 samples.H. pylori DNA was detected in 39 gastric juice samples (100%) and in 28 saliva samples (71.8%). The prevalence in urine samples was 50% (13/26). All samples except one were identical with over 97% identity to the DNA sequence of H. pylori type strain J99 (USA).Nested PCR was highly sensitive for detection of H. pylori DNA in saliva, DNA sequencing may be useful to clarify the mode of transmission.