PCR detection of Brachyspira aalborgi and Brachyspira pilosicoli in human faeces

previously-developed PCR protocols specific for the 16S rRNA gene of the intestinal spirochaetes Brachyspira aalborgi and Brachyspira pilosicoli were adapted for the detection of these species in human faeces, following DNA extraction and purification using mini-prep columns. The limits of detection in seeded farces for B. aalborgi and B. pilosicoli respectively were 2 x 10(2) and 7 x 10(3) cells per PCR reaction, equivalent to 5 X 10(4) and 1 x 10(5) cells per g of faeces. The PCR techniques were applied to faecal samples from two patients with histological evidence of intestinal spirochaetosis. In the first patient, in whom B. aalborgi had been identified by 16S rDNA PCR from colonic biopsies. a positive amplification for B. aalborgi only was obtained from the faeces. The organism could not be isolated from these faeces. In the second patient, both colonic biopsies and Faeces were PCR positive for B. pilosicoli only, and B, pilosicoli was isolated from the faeces. These new faecal PCR protocols should be valuable for future studies on the epidemiology of intestinal spirochaete infections in human populations, particularly as it is not currently possible to isolate B. aalborgi from faeces. (C) 2001 Federation of European Microbiological Societies. Published by Elsevier Science B.V. All rights reserved.