Coinfection of Helicobacter pylori and Neisseria subflava is closely associated with lymph follicle formation in human stomach

Summary

Background

Many reports have described coinfection of Helicobacter pylori and other bacteria in the gastric mucosa in humans. However, relatively few have reported the relation of coinfection with pathological characteristics.

Aim

To culture and identify bacteria other than H. pylori from the gastric mucosa of 64 patients undergoing scheduled gastric biopsy for various gastric conditions. The relation of coinfection with the pathological changes was also investigated.

Methods

From colonies showing characteristics different to those of H. pylori, bacteria were identified by the 16S rRNA gene sequence using FASTA. Cluster analysis was performed using GENETYX-MAC and a phylogenetic tree was constructed using the UPGMA method. The correlation of pathological observation and the existence of identified bacteria and H. pylori were also analysed.

Results

Forty-eight per cent of patients were positive to H. pylori, and 27% were positive to Neisseria species. Coinfection of the two bacterial existences was significantly linked. DNA sequencing studies revealed these Neisseria strains to coincide mostly with Neisseria subflava. With regard to the interaction of pathological characteristics, Neisseria and H. pylori coinfection was closely related to lymph follicle formation.

Conclusions

Coinfection of H. pylori and N. subflava was found to be closely related to lymph follicle formation.