False-colour transmission electron micrograph (TEM) of Campylobacter fetus, a species of bacteria causing gastro-enteritis (diarrhoea) in humans, especially infants. The individual, curved, highly mobile, Gram-negative bacterium also infects farm animals. Possible routes of human infection include drinking unpasteurized milk & eating infected poultry. Treatment is with antibiotics such as erythromycin, ampicillin, & tetracycline. Magnification: x29,000 at 35mm size.