coccal forms of Helicobacter pylori

Studies conducted by Ng et al. (1985) found that within colonies of H. pylori, the circular, or coccoid forms were found at the centre of the colony while the spiral forms were found at the edges and were actively dividing.

It is theorized that the circular form of H. pylori is inactive and represents a survival adaptation which allows the organism to survive unfavourable conditions (Curry & Jones 1990).

It is also theorized that it is the coccal forms that are involved in the transmission of H. pylori.

In prolonged culture the morphology of Helicobacter pylori alters from “the normal” helical form to a spherical cell via U- and V-shaped forms. This morphological transformation may be the result of less than optimal cultural conditions, a reaction to waste products, or it may be a natural phenomenon.