Abstract
Spiral-shaped bacteria with a distinctive morphology were isolated from the intestinal mucosa of rats and mice on a campylobacter selective medium using microaerophilic incubation. These bacteria have been shown by other authors to be present in the intestinal tracts of several animal species but have not been cultured previously. The results of electron microscopic examinations and biochemical testing have shown that these organisms do not correspond to any known genus. Colonization experiments with pure cultures in gnotobiotic rodents have shown these bacteria to be mucosa associated, with a particular affinity for intestinal crypts. The pattern of colonization of the intestinal crypts in gnotobiotes known to be free of other mucosa-associated organisms differed from the colonization occurring in conventional animals that possess a normal mucosa-associated flora.