helicobacter pullorum helicobacter pullorum helicobacter pullorum is a bacterium in the helicobacteraceae family, campylobacterales order. it was isolated from the liver, duodenum, and caecum of broiler and layer chickens, and from humans with gastroenteritis. it is a nongastric urease-negative helicobacter species colonizing the lower bowel. helicobacter pullorum scientific classification domain: bacteria phylum: campylobacterota class: "campylobacteria" order: campylobacterales family: helicobacteraceae genus: helicobacter species: h. pullorum binomial name helicobacter pullorumstanley et al. 1994