Detection and Analysis of <i>Helicobacter pylori</i> DNA in the Gastric Juice, Saliva, and Urine by Nested PCR / Oral Science International

ABSTRACT

The aim of this study was to investigate the strain heterogeneity of <i>Helicobacter pylori (H. pylori)</i> in saliva, gastric juice, and urine by nested PCR and the direct sequence method, and to clarify the mode of transmission by examining whether <i>H. pylori</i> in the stomach and saliva are identical.Thirty-nine patients undergoing endoscopy were enrolled in this study. <i>H. pylori</i> 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.<i>H. pylori</i> 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 <i>H. pylori</i> type strain J99 (USA).Nested PCR was highly sensitive for detection of <i>H. pylori</i> DNA in saliva, and DNA sequencing may be useful to clarify the mode of transmission.