Detection of a putative novel Wolinella species in patients with squamous cell carcinoma of the esophagus

Background. Certain regions of South Africa exhibit an extraordinarily high incidence of esophageal carcinoma that develops via an esophagitis-dysplasia-carcinoma sequence. Bacteria belonging to the family Helicobacteraceae are candidates for involvement in the initiation of the esophagitis. We investigated patients with esophageal carcinoma for the occurrence of Helicobacter-related species. Methods. Biopsies from tumor and nonlesional tissue of the esophagus from nine patients with squamous cell carcinoma were investigated for Helicobacteraceae using a PCR-based method targeting the 16S rRNA gene. Results. Four out of nine patients tested negative, while samples from the other five patients revealed an infection by different Helicobacter species. Sequence analysis of the PCR fragments led to the identification of a hitherto unknown bacterium in three of these patients. Phylogenetically, this bacterium was assigned to the genus Wolinella within the family of Helicobacteraceae. Helicobacter pylori was identified in three patients, and one revealed a coinfection with the novel Wolinella species. Conclusions. Helicobacteraceae were detected in approximately 50% of South African patients with esophageal carcinoma. Furthermore, a novel bacterium was identified that might be linked to the enhanced incidence of esophagitis and subsequent malignant disease in South Africa.