Genus of bacteria that cause serious outbreaks of gastroenteritis. They grow best at 43şC, and so are well suited to the digestive tract of birds. Poultry is therefore the most likely source of a Campylobacter outbreak, although the bacteria can also be transmitted via beef or milk. Campylobacter can survive in water for up to 15 days, so may be present in drinking water if supplies are contaminated by sewage or reservoirs are polluted by sea gulls.