Carriage of intestinal spirochaetes by humans: epidemiological data from Western Australia

Abstract

SUMMARYThe purpose of this study was to investigate carriage of intestinal spirochaetes by selected population groups in Western Australia. Stool specimens from 293 rural patients with gastrointestinal disorders, and from 227 healthy migrants from developing countries were cultured. Spirochaete isolates were identified using PCR, and typed by pulsed field gel electrophoresis (PFGE). Brachyspira aalborgi was not isolated. Brachyspira pilosicoli was recovered from 15 rural patients, all Aboriginal. Prevalence was 9n9 % in 151 Aboriginals and 0 % in 142 non-Aboriginals. Carriage of B. pilosicoli amongst migrants was 10n6 % (24\227). Carriage was significantly increased in Aboriginal children aged 2-5 years (P l 0n0027) and in migrant individuals from the Middle East and Africa (P l 0n0034). Carriage was significantly associated with detection of faecal protozoa in both Aboriginals (P l 0n0021) and migrants (P l 0n012). PFGE results indicated that the B. pilosicoli strains were genetically diverse.

Colonization and risk factors for Brachyspira aalborgi and Brachyspira pilosicoli in humans and dogs on tea estates in Assam, India

“…Immigrants to Western Australia from a variety of developing countries have been shown to have a colonization rate of 10 . 6% on arrival in Australia [13]. The similarities between the prevalences in these studies helps to validate the accuracy of PCR as used here for detection of B. pilosicoli in faeces, and suggests that the dichromate treatment of the samples did not have a deleterious effect on the sensitivity of the tests.…”

“…It has been shown to colonize approximately 30 % of individuals in developing countries including Oman [8] and Papua New Guinea [9], and, in developed countries, occurs at a similarly high prevalence in Aboriginal people in Australia [10], male homosexuals [3] and patients infected with human immunodeficiency virus (HIV) [11]. By comparison, it is uncommon in the faeces of the general population in developed countries [10,12,13]. It is also regularly found in the large intestines of a variety of animal species including pigs [2], chickens [14], water birds [15], and dogs [16].…”

Comparison of prevalence and risk factors for faecal carriage of the intestinal spirochaetes Brachyspira aalborgi and Brachyspira pilosicoli in four Australian populations

“…Of these, 514 samples from rural patients and migrants had been used in a previous culture-based study of B. pilosicoli, and further details of the sources of these samples have been published [13]. The other 36 samples from the previous study (all from rural Aboriginal people) were not used because either they represented multiple samples from the same individual, or there was insufficient sample available.…”

“…It is usually detected by polymerase chain reaction (PCR) or gene probe assays, and has only occasionally been isolated [5][6][7]. B. pilosicoli is easier to isolate, and has been cultured from faeces in several developing countries [8][9][10][11], from Australian Aborigines [12,13], migrants to Australia from developing countries [13] and homosexual males [14]. Prevalence rates for B. pilosicoli in the faeces of these populations vary from y10 to 50%.…”

“…We used specific PCRs for the two species on DNA extracted from faeces. Most samples previously had been investigated for B. pilosicoli by culture [13]. This allowed additional comparison of the usefulness of faecal culture compared to PCR for detection of B. pilosicoli, and helped ensure the quality control on the B. aalborgi faecal PCR.…”