Only limited data concerning the prevalence of intestinal spirochetes are available in game birds. This paper describes the prevalence and biochemical reactions of spirochetes isolated from 25 common partridges, 7 pheasants and 16 mallards originating from nine Swedish game-bird farms. The birds, which had been submitted for post-mortem examination due to various problems, showed a variety of underlying diseases. Additionally, fecal droppings from 22 common partridges, 20 pheasants and 20 mallards obtained at one of the farms were included in the study. Intestinal spirochetes were isolated from 85.4% of the game birds and from 71% of the fecal droppings. Seven biochemical types were identified. Seventeen per cent of all isolates were classified as Brachyspira pilosicoli and 3% as B. intermedia. One isolate showed strong -hemolysis and a positive indole reaction that is consistent with B. hyodysenteriae. In addition, three previously unknown biochemical types were found. Unclassified spirochetes in presumed mixed cultures were observed in 21% of all samples of fecal droppings. Histologic examination of spirochete-positive birds revealed numerous spirochetes in the lumen and crypts of the cecum, in some cases densely adhered by one end to the luminal surface. The significance of the findings is discussed.

Intestinal spirochetosis in humans (HIS) is a condition defined by the presence of a layer of spirochetes attached by one cell end to the colorectal epithelium. The pathologic significance of HIS is uncertain, but it has been linked to chronic diarrhea and other abdominal complaints. Two anaerobic intestinal spirochete species have been associated with HIS, namely Brachyspira pilosicoli and Brachyspira aalborgi. Brachyspira pilosicoli, which colonizes many animal species, is common (~30%) in the feces of people from developing countries, including Australian Aborigines, and in HIV+ patients and male homosexuals in Western societies. It is also commonly seen attached to the rectal mucosa of homosexual males. In other groups in Western societies both the presence of B. pilosicoli in feces and histologic HIS are uncommon (~1.5%). Brachyspira aalborgi is an extremely slow growing and fastidious spirochete, which previously had been isolated from an HIS patient in Denmark. Recent studies using polymerase chain reaction amplification of DNA from intestinal biopsies from a series of cases of HIS in the general Western population demonstrated that B. aalborgi, rather than B. pilosicoli, was the main spirochete species involved in these patients. This review outlines recent developments in the study of HIS and the two spirochete species, and identifies priorities for future research.

DNA was extracted from colonic biopsies of 33 patients with and three without evidence of intestinal spirochetosis (IS) in the large bowel. The biopsies were subjected to PCR. A pair of primers, generating a 207 bp fragment, were designed to detect specifically the 16S rDNA gene of Brachyspira. PCR products of the expected size were obtained from 33 samples with histologic evidence of IS. The PCR amplicons were used for sequencing. The sequences obtained were aligned to the corresponding 16S rRNA sequences of five type strains of Brachyspira. The sequences of 23 PCR products were 99–100% identical with the correspond-ing B. aalborgi type strain sequence. Two cases showed 99–100% sequence similarity with the type strain of B. pilosicoli P43/6/78. Six cases could not be referred to any of the known species of Brachyspira. Two PCR products gave incomplete sequences.

The prevalence of human intestinal spirochetosis (HIS) was determined histologically in 402 subjects from South Norway (Kristiansand) who had undergone colorectal resections during the period June 1991–June 1996. The figures were compared with those from a previous mid-Norwegian study (Trondheim)1 comprising 1205 patients with large bowel resections as well as colonoscopic mucosal biopsies examined in 1990. The studies showed a prevalence of HIS of 2.5% in mid-Norway and 3.0% in South Norway, and in both regions there was a considerable male predominance of HIS (70% and 75%, respectively). Furthermore, HIS was more often diagnosed by the pathologists in South Norway (25%) than in mid-Norway (6.5%).