Isolation of Serpulina pilosicoli from environmental and other sources on a piggery

The intestinal spirochaete Serpulina pilosicoli causes intestinal spirochaetosis (IS), a diarrhoeal disease of pigs and other species. This condition is widespread, though often undiagnosed, and causes losses to the pig industry through reduced growth rates and poor feed conversion (3). Very little is known about the epidemiology. Porcine intestinal spirochaetosis (PIS) is a diarrhoeal disease of weaners and growers, associated with a mild colitis. Control of the aetiological agent, Serpulina pilosicoli, has relied mainly on the use of antimicrobial agents. In contrast, besides the use of antimicrobials and appropriate management practices, it is our experience that the closely related Serpulina hyodysenteriae (the agent of swine dysentery) can also be partially controlled by bacterin vaccines (1), whilst experimentally-infected pigs totally resist challenge if fed• a diet based on cooked white rice and animal protein (4, 5). This diet results in reduced microbial fermentation in the large intestine, and it appears that these conditions inhibit colonisation by the spirochaete. The purpose of the present study was to assess whether the use of a bacterin vaccine or a rice-based diet could similarly inhibit colonisation by S. pilosicoli

Evaluation of vaccination and diet for the control of Serpulina pilosicoli infection (porcine intestinal spirochaetosis)

Porcine intestinal spirochaetosis (PIS) is a diarrhoeal disease of weaners and growers, associated with a mild colitis. Control of the aetiological agent, Serpulina pilosicoli, has relied mainly on the use of antimicrobial agents. In contrast, besides the use of antimicrobials and appropriate management practices, it is our experience that the closely related Serpulina hyodysenteriae (the agent of swine dysentery) can also be partially controlled by bacterin vaccines (1), whilst experimentally-infected pigs totally resist challenge if fed a diet based on cooked white rice and animal protein (4, 5). This diet results in reduced microbial fermentation in the large intestine, and it appears that these conditions inhibit colonisation by the spirochaete. The purpose of the present study was to assess whether the use of a bacterin vaccine or a rice-based diet could similarly inhibit colonisation by S. pilosicoli

Isolation of Brachyspira pilosicoli from environmental and other sources on a piggery

The intestinal spirochaete Brachyspira pilosicoli causes intestinal spirochaetosis (IS), a diarrhoeal disease of pigs and other species. This condition is widespread, though often undiagnosed, and causes losses to the pig industry through reduced growth rates and poor feed conversion (1). Relatively little is known about the epidemiology of the infection, although it is assumed that faecaloral cycling between pigs is responsible for transmission within and between piggeries. Nevertheless, other animals and birds have been shown to be colonised by this organism, and they may play a part in transmission. There is evidence that B. pilosicoli can be transmitted between species. In a study in Papua New Guinea, pulsed field gel electrophoresis was used to show that some isolates of B. pilosicoli from humans were identical to strains isolated from dogs (2). In addition, experimental infection of day-old chicks and newly weaned pigs using human strains of B. pilosicoli has induced disease consistent with porcine IS (3). Survival of this organism in contaminated slurry or water may also play a part in persistence of infection in a piggery. B. pilosicoli is able to withstand adverse environmental conditions better than B. hyodysenteriae (the causative agent of swine dysentery), and B. pilosicoli has been isolated from the faeces of waterbirds and water in a lake that supported a large bird population (4). The purpose of this study was to investigate environmental and other sources of B. pilosicoli that could be involved in the cycle of infection on a piggery

Extraintestinal colonisation by Serpulina pilosicoli in an experimentally inoculated pig

The intestinal spirochaete Serpulina pilosicoli colonises the porcine large intestine where characteristically, but not invariably, large numbers of these bacteria become attached by one cell end to the mucosa (4). This colonisation can induce a colitis and a diarrhoeal disease called intestinal spirochaetosis (IS). Besides pigs, IS occurs naturally in various species of birds, as well as in dogs and human beings. Recently, S. pilosicoli was isolated from the bloodstream of a series of debilitated and/or immunocompromised human patients, some of whom subsequently died (5). It is not known whether S. pilosicoli can also invade and colonise extraintestinal sites in pigs, whether immunosupression would be necessary for this to occur, nor what the clinical outcomes might be. The current experiment was undertaken to investigate these possibilities, using pigs inoculated intravenously with the spirochaete so as to maximise the opportunity for colonisation to occur

Colonisation of pet shop puppies with Brachyspira pilosicoli

Anaerobic intestinal spirochaetes of the genus Brachyspira are known to colonise dogs, but relatively little is known about their prevalence, distribution or pathogenic potential. One species, Brachyspira pilosicoli, is thought to cause diarrhoea in dogs, as well as in other animals and humans. To investigate the prevalence and distribution of infection, faecal samples from 49 puppies from six pet shops in the suburbs of Perth, Western Australia were subjected to selective culture for anaerobic intestinal spirochaetes. Growth from the primary plates was also harvested, the DNA extracted and a polymerase chain reaction (PCR) amplification of a portion of the 16S rRNA gene of B. pilosicoli applied. Weakly beta-haemolytic intestinal spirochaetes (WBHIS) grew on plates from 20 of the dogs (40.8%). Seven plates (14.2%) yielded PCR positive amplification for B. pilosicoli. Seven WBHIS isolates were obtained in pure culture, and two of these were shown to be B. pilosicoli by PCR. Application of multilocus enzyme electrophoresis to the seven isolates confirmed that the two PCR positive isolates were B. pilosicoli, whilst the other five belonged to a group previously designated "Brachyspira canis". All the "B. canis" isolates came from healthy puppies, suggesting that this WBHIS is a commensal. Three of the seven puppies with PCR evidence of B. pilosicoli had diarrhoea, but the sample size was small and the association between colonisation and diarrhoea was not statistically significant. Pet shop puppies are commonly infected with intestinal spirochaetes, and may act as a reservoir of B. pilosicoli for other animals and humans

Epidemiological studies of Brachyspira pilosicoli in two Australian piggeries

The epidemiology of infection with the intestinal spirochaete Brachyspira pilosicoli within pig herds is incompletely understood. To investigate this further, cross-sectional and cohort studies were undertaken on two piggeries. Faeces were subjected to selective culture, and DNA was extracted from growth on the primary media and amplified by polymerase chain reaction (PCR). On one farm, samples from other animal species and the environment were also examined. Isolates were subjected to multilocus enzyme electrophoresis (MLEE) and pulsed field gel electrophoresis (PFGE). The prevalence on farm A (>2000 sows) was 2.4% (95% confidence interval (CI): 0.3, 4.4%). Infection was largely confined to grower/finisher pigs. The six isolates of B. pilosicoli recovered belonged to a single MLEE electrophoretic type (ET) and a single PFGE type. On piggery B, an 80-sow unit located on a research farm, the prevalence amongst growers and finishers was 12.2% (95% CI: 4.7, 19.6%). There was also evidence that weaners were being infected. Ten isolates obtained were genetically heterogeneous, being divided into six ETs and seven PFGE types. One of four isolates in one ET had an identical PFGE type to those on piggery A, and may have been introduced to piggery B in stock from piggery A. On farm B, B. pilosicoli was also detected by PCR in chickens, effluent pond water and wild ducks on the pond. An isolate from the pond belonged to the same ET as one from a pig, whereas the duck isolates were distinct. This study demonstrates the complex epidemiology of B. pilosicoli infections in piggeries

Distribution and strain typing of Brachyspira pilosicoli in two Western Australian piggeries

The intestinal spirochaete Brachyspira pilosicoli causes intestinal spirochaetosis (IS), a diarrhoeal disease first recognised in 1980. This condition results in production losses due to reduced growth rates and poor feed conversion. The purpose of this study was to investigate the distribution and strain diversity of B. pilosicoli on two piggeries in Western Australia

Serpulina pilosicoli: a water-borne pathogen?

Serpulina pilosicoli is recognised as the causative agent of intestinal spirochaetosis (IS), a diarrhoeal disease which affects a variety of vertebrate hosts including pigs, dogs, birds and humans, It is commonly isolated from the faeces of individuals in developing communities, HIV positive patients and homosexual males in western societies. Additionally S. pilosicoli has been isolated from the bloodstream of debilitated patients. In order to determine the potential sources of human contamination, water from a lake at Perth Zoological Gardens and faeces from 43 water birds frequenting the lake were examined. S. pilosicoli was isolated and identified from eight of the 43 faecal samples (18.6%) and from three of the seven (42.8%) samples of lake water. A subset of 17 faecal samples were subjected to DNA extraction and PCR after primary culture, and eight (47%) were positive for S. pilosicoli DNA. Experimentally, S. pilosicoli was shown to survive in lake water for more than one month and in tap water for from one to 14 days. A volunteer who drank 1 x 10 9 cells of an S. pilosicoli strain mixed with tap water on three successive days became colonised with the same strain. The results suggest that water contaminated with faeces containing S. pilosicoli could be a source of infection for humans and animals

Comparative in vitro sensitivity of Serpulina hyodysenteriae and Serpilona pilosicoli isolates to six antimicrobials

The pathogenic intestinal spirochaetes Serpulina hyodysenteriae and Serpulina pilosicoli are the respective agents of swine dysentery (SD) and porcine intestinal spirochaetosis (PIS). Swine dysentery is a severe mucohaemorrhagic colitis, while PIS is a less severe diarrhoeal disease causing reduced growth rates and loss of condition. SD and PIS are both common diseases in Australia, and cause major production losses. Control of SD and PIS on infected piggeries relies heavily on the use of antimicrobial agents. For this reason, comprehensive in vitro antimicrobial sensitivity studies have been performed on isolates of S. hyodysenteriae (2,6, 4, 1). Unfortunately, because S. pilosicoli has only recently been described, very little information has been gathered on susceptibility of isolates of this species. Previous studies have investigated the antimicrobial sensitivities of uncharacterised weakly B-haemolytic intestinal spirochaetes (3), however it is now realised that these are likely to have included several species of the genus Serpulina, some of which are pathogenic and some apparently benign. The purpose of this work was to make a comparative study of the antimicrobial sensitivities of a range of isolates of S. hyodysenteriae and S. pilosicoli

Identification and characterization of Serpulina pilosicoli isolates recovered from the blood of critically ill patients

The phenotypic and genetic characteristics of spirochetes isolated from the blood of one U.S. and six French patients with severe clinical disease or impaired immunity were examined. All spirochetes were anaerobic, weakly beta-hemolytic, positive for hippurate hydrolysis, and negative for beta-glucosidase activity. Cell lengths ranged from 4 to 8 microm, and each isolate had between 8 and 12 periplasmic flagella per cell. These features were consistent with the spirochetes' being Serpulina pilosicoli, the agent of intestinal spirochetosis. All isolates were positive in a PCR assay amplifying a portion of the S. pilosicoli 16S rRNA gene, and they all grouped with fecal isolates of S. pilosicoli in multilocus enzyme electrophoresis (MLEE). The blood isolates could be differentiated from each other by MLEE, although the U.S. and two French isolates were closely related. Apparently S. pilosicoli may translocate from the large intestine to establish spirochetemia. The clinical significance of this finding remains uncertain and requires further investigation