Helicobacter

General information

Helicobacter spp. are helical or curved, gram-negative bacteria. For culture, they need especially enriched culture media. The Helicobacter genus comprises at least 35 species. Some Helicobacter species colonise the gastric mucosa, while others colonise the intestine and liver of humans or animals. In humans, Helicobacter pylori is correlated with gastritis and stomach ulcers, but it is not normally relevant in animals. It is an anthroponotic disease – in other words, an infection of an animal with a human pathogen.

Pathogenicity of Helicobacter spp. in animals has not yet completely been clarified. Helicobacter mustelae was detected in ferrets with gastritis and stomach ulcers, Helicobacter heilmanii was found in pigs with stomach ulcers. They also seem to be associated with gastritis, vomiting and inappetence in dogs and cats. Prevalence is very high, both in healthy as well as in infected animals. Hence, an infection does not always lead to the outbreak of the disease. It is likely that the clinical picture is also influenced by the present Helicobacter spp. (mixed infections are frequent) as well as by the individual host response and environmental factors.

Gastric Helicobacter spp. include H. felis, H. bizzozeronii, H.heilmannii, H. salomonis; the intestinal ones comprise H. canis, H. bilis, H. cinaedi, Flexispira rappini. Transmission occurs by oral-oral route, or possibly also by anal-oral route. Flexispira rappini, which is also assigned to the Helicobacter genus, is associated with the occurrence of abortions in sheep. Aborted lambs show multifocal hepatic necroses which are similar to the liver lesions seen in campylobacter infections.