Isolation of the anaerobic intestinal spirochaete Brachyspira pilosicoli from long-term residents and Indonesian visitors to Perth, Western Australia.

Brachyspira pilosicoli is an anaerobic spirochaete that colonizes the large intestine of humans and various species of animals and birds. The spirochaete is an important enteric pathogen of pigs and poultry, but its pathogenic potential in humans is less clear. In the current study, the occurrence of B. pilosicoli in faecal samples from 766 individuals in two different population groups in Perth, Western Australia, was investigated by selective anaerobic culture. Of 586 individuals who were long-term residents of Perth, including children, elderly patients in care and in hospital and individuals with gastrointestinal disease, only one was culture positive. This person had a history of diverticulitis. In comparison, faeces from 17 of 180 (9.4 %) Indonesians who were short- or medium-term visitors to Perth were positive for B. pilosicoli. The culture-positive individuals had been in the city for between 10 days and 4.5 years (median 5 months). Resampling of subsets of the Indonesians indicated that all negative people remained negative and that some positive individuals remained positive after 5 months. Two individuals had pairs of isolates recovered after 4 and 5 months that had the same PFGE types, whilst another individual had isolates with two different PFGE types that were identified 2 months apart. Individuals who were culture-positive were likely to have been either colonized in Indonesia before arriving in Perth or infected in Perth following contact with other culture-positive Indonesians with whom they socialized. Colonization with B. pilosicoli was not significantly associated with clinical signs at the time the individuals were tested, although faeces with wet-clay consistency were 1.5 times more likely (confidence interval 0.55-4.6) than normal faeces to contain B. pilosicoli.

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.

Prevalence, risk factors and molecular epidemiology of Brachyspira pilosicoli in humans on the island of Bali, Indonesia.

The purpose of this study was to investigate the prevalence and epidemiology of the anaerobic intestinal spirochaete Brachyspira pilosicoli amongst Indonesians living in rural and urban settings on the island of Bali. Faecal samples (n = 992) were collected on two occasions, 4 months apart, from people living in four traditional farming villages, one peri-urban location and one urban area. Samples were cultured anaerobically on selective agar and intestinal spirochaete isolates were confirmed to be B. pilosicoli by using a species-specific PCR. Forty-eight of the 121 isolates obtained were typed by using PFGE. A questionnaire was administered to participants and analysed in order to identify potential risk factors for colonization. Overall prevalence of carriage on the two visits was 11.8 and 12.6 %, respectively. Prevalence at different locations varied from 3.3 to 23.4 %, with the highest prevalence occurring in the peri-urban location. Considerable strain diversity was found, with the 48 isolates being divided into 44 PFGE types. There was no significant association between colonization and ownership of animals, contact with animals, farming, age or gender. On the first visit, colonization was significantly more common in people who used well water compared to those who used tap water. On the second visit, colonization was significantly more common in people with wet faeces than in those with normal faeces.

Evaluation of blood culture systems for detection of the intestinal spirochaete Brachyspira (Serpulina) pilosicoli in human blood.

The anaerobic intestinal spirochaete Brachyspira (Serpulina) pilosicoli has been isolated from the bloodstream of French patients by manual blood culture systems. The purpose of this study was to determine whether the automated and manual blood culture systems used in Australia are suitable for growth and detection of this organism. Strains of B. pilosicoli were added to human blood to give concentrations ranging from 1 x 10(4) to 1 x 10(1) spirochaetes/ml and 10-ml volumes were inoculated into the media. Three strains of B. pilosicoli grew slowly in all manual Hemoline and BBL Septi-Chek formulations tested. Subcultures taken between 2 and 10 days after inoculation yielded growth only after incubation for a further 5-8 days. Growth and automated detection were achieved in the BACTEC system with Anaerobic/F medium with or without Fastidious Organism Supplement. Minimum time to signal for nine strains varied between 5.6 and 14.9 days, with a minimum concentration of 10(1) spirochaetes/ml of blood being detected. None of nine strains gave a positive signal in the BacT/Alert system when FAN Anaerobic culture bottles were used; however, four strains were detected by subculture taken at 7 or 14 days after inoculation. When Anaerobic medium was used in the BacT/Alert system, two of three strains gave a signal and the other strain grew and was detected by subculture. Spirochaetaemias caused by B. pilosicoli may be unrecognised because detection time by the signal or subculture exceeds 5 days.