Helicobacter species ribosomal DNA recovered from the liver tissue of Chinese patients with primary hepatocellular carcinoma

Using polymerase chain reaction (PCR), we examined 16S ribosomal DNA (rDNA) of Helicobacter species in liver tissue specimens obtained from 15 patients with hepatocellular carcinoma. Sixty percent (9 of 15) of these specimens were found to be positive for Helicobacter species. Four 16S rDNA fragments from positive PCR samples were directly sequenced. By sequence comparison, all were found to be 99% identical to the 16S rRNA of Helicobacter pylori.