 The Epsilonproteobacteria consist of few known genera, mainly the curved to spirilloid "Wolinella" spp., "Helicobacter" spp., and "Campylobacter" spp.Most of the known species inhabit the digestive tracts of animals and serve as symbionts ("Wolinella" spp.in cattle) or pathogens ("Helicobacter" spp.