An unexpectedly high prevalence of colonization with the intestinal spirochaete Brachyspira aalborgi amongst residents of the Indonesian island of Bali.

PCR assays designed to amplify DNA from the anaerobic intestinal spirochaete Brachyspira aalborgi were conducted on DNA extracted from 938 faecal samples from 469 residents on the Indonesian island of Bali. The individuals tested were sampled twice in one year and were from four rural villages, one peri-urban centre and the capital city, Denpasar. Overall, an unexpectedly high prevalence of colonization (24.7%) was found, with prevalence rates at different locations varying from a low of 15.6% at one village to 41.5% in the peri-urban centre. Comparison of prevalence rates at the two sampling times suggested that, in many individuals, colonization was likely to be prolonged (>3 months) and/or that reinfection was occurring frequently in these people. Analysis of a questionnaire administered to the individuals who were sampled identified specific risk factors for colonization as location, co-colonization with the related intestinal spirochaete Brachyspira pilosicoli and use of drinking water obtained from wells rather than from taps. No specific associations with clinical symptoms were identified.

Analysis of genetic variation in Brachyspira aalborgi and related spirochaetes determined by partial sequencing of the 16S rRNA and NADH oxidase genes.

The purpose of this study was to investigate genetic variation in the anaerobic intestinal spirochaete Brachyspira aalborgi by partial sequencing of the 16S rRNA and NADH oxidase genes. The spirochaete is poorly cultivable; hence, only six isolates were available for analysis. Additional sequences were amplified from DNA extracted from fixed colorectal biopsies from 26 patients with histological evidence of intestinal spirochaetosis, and from the faeces of six non-human primates (NHP). Multiple biopsies from sites along the large intestine were tested from three of the 26 patients. Sequences from two biopsies were closely related to those of the spirochaete Brachyspira pilosicoli. Eight B. aalborgi-like 16S rDNA sequences were generated from the biopsies from the other 24 patients, and four from the NHP faeces. The B. aalborgi 16S rDNA sequences were divided into three clusters, 1, 2 and 4, with individual sequence similarities to the type strain ranging from 97.49 to 100 %. All human isolates of B. aalborgi were located in cluster 1, as was the sequence of the so-called 'Brachyspira ibaraki'. All four 16S rDNA sequences from the NHP faeces and the two NHP isolates of B. aalborgi were located in cluster 4, which was distinct. Cluster 4 may represent a novel Brachyspira species. Evidence for multiple strains of B. aalborgi or other Brachyspira species was found in biopsies from two patients. In the three individuals from whom multiple biopsies were amplified, the sequences at each intestinal site were the same, indicating the presence of one dominant strain.

Detection by PCR and isolation assays of the anaerobic intestinal spirochete Brachyspira aalborgi from the feces of captive nonhuman primates.

The purpose of this study was to investigate the presence of the anaerobic intestinal spirochetes Brachyspira aalborgi and Brachyspira pilosicoli in the feces of captive nonhuman primates (n = 35) from 19 species housed at the Zoological Gardens, Perth, Western Australia. Both spirochete species are known to infect human beings. DNA was extracted from freshly collected feces with a commercially available QIAamp DNA stool minikit and subjected to PCR protocols amplifying portions of the 16S rRNA genes of the two spirochete species. The feces were also subjected to selective culture for the spirochetes. Subsequently, feces from 62 other captive animals or birds representing 39 species at the zoo were examined by PCR to determine whether they were reservoirs of infection. Six fecal samples from individuals from four primate species (two vervet monkeys, two Tonkean macaques, one Japanese macaque, and one hamadryas baboon) tested positive in the B. aalborgi PCR. B. aalborgi was not detected by PCR in any of the other animal or bird species tested, and B. pilosicoli was not detected in the primates or any of the other animals or birds. B. aalborgi was isolated from both PCR-positive vervet monkeys. This is the first time that B. aalborgi has been isolated from nonhuman primates and the first time that it has been isolated from the feces of any species.