Cell wall-defective variants of pseudomonas-like (group Va) bacteria in Crohn's disease.

Several animal transmission studies have indicated that Crohn's disease may be caused by a filterable agent. Filtrates of homogenized tissues were prepared from 8 patients with Crohn's disease, 9 patients with chronic ulcerative colitis, and 20 control patients without inflammatory bowel disease. Conventional bacteriological cultures and hypertonic cultures for cell wall-defective bacterial variants were performed on the filtrates. Bacterial revertants (parent forms) of cell wall-defective variants were obtained from filtrates of various tissues including mesenteric lymph nodes of all patients with Crohn's disease. In no instance were revertants cultured from tissue filtrates of the other patients. The 11 revertants isolated from the 8 patients were identified as Pseudomonas-like bacteria, most closely identifiable with group Va.