A newly developed PCR assay ofH. pylori in gastric biopsy, saliva, and feces

Abstract

We have recently developed a new PCR assay for the detection ofH. pylori. In this study, the polymerase chain reaction (PCR) assay was used to detectH. pylori in 88 gastric biopsy, 85 saliva, and 71 fecal specimens from 88 patients.H. pylori infection was confirmed in 71 of 88 patients by culture and/or histological stain of gastric biopsies. Serum IgG antibody toH. pylori was also measured and resulted in 97% sensitivity and 94% specificity.H. pylori DNA was detected by the PCR assay in gastric biopsy specimens from all 71 patients (100% sensitivity) with proven gastricH. pylori infection but not from 17 noninfected patients (100% specificity). In saliva specimens,H. pylori DNA was identified in 57 of the 68 patients (84%) with proven gastricH. pylori infection and in three of the 17 patients without gastricH. pylori infection. However, the PCR assay was only able to detectH. pylori DNA in the feces from 15 of 61 patients (25%) with proven gastricH. pylori infection and one of the 10 patients without gastricH. pylori infection. The results show that the PCR assay is reliable for detecting the presence ofH. pylori in gastric biopsy and saliva specimens. The data indicate thatH. pylori exists in a higher prevalence in saliva than feces and that the fecal-oral route may be an important means of transmission of this infection in developing countries but not as significant as previously suspected in the developed countries. It is likely that the oral-oral route is more prominent.