the following information is not yet verified
Gram negative helical, curved or straight rods with rounded ends sometimes forming rare spiral shapes.

0.3-0.6 x 1-10 µm

In older culture, Helicobacter pylori cells become coccoid, with an associated decrease in ability to subculture.

Microaerophilic, require 5-10% CO2 and high humidity.
They are fastidious organism. They grow best at 37°C but not at 43°C and below 30°C. BA: translucent to pale grayish colonies of 0.5 to 1 mm in size.

James Versalovic et al.(2011) Manual of Clinical Microbiology 10th Edition