Non-pylori Helicobacter infections in humans.

The spectrum of human non-pylori Helicobacter infections is expanding. Evidence for the presence of bacteria such as H. heilmannii, H. felis, H. rappini, H. cinaedi, H. fennelliae and H. pullorum has been reported. These bacteria are likely to be associated with different clinical disorders. H. heilmannii is the most commonly described non-pylori Helicobacter in humans. Colonization with this bacterium is usually associated with mild gastritis. In some cases, gastric ulcer disease may occur. H. heilmannii are classified as such on the basis of morphological criteria. Recent phenotypical and genotypical data suggest that this is insufficient. Therefore, for a better understanding of the relation between non-pylori Helicobacter species and disease, there is a need for studies focusing on genetic instead of morphological criteria.