Molecular epidemiological study of Brachyspira pilosicoli in Finnish sow herds.
(9/91)
Brachyspira (B.) pilosicoli, the causative agent of intestinal spirochaetosis in pigs, is a quite common laboratory finding from faecal samples of weaned and growing pigs in Finland. A better understanding of the epidemiology of B. pilosicoli in and between Finnish pig farms is needed. Altogether 131 B. pilosicoli isolates from 49 Finnish sow herds were studied by pulsed-field gel electrophoresis. MluI was used as a restriction enzyme for all the isolates, and SmaI for 70 isolates. The isolates were divided into 54 different macrorestriction profiles (MRP) by MluI. Most farms had distinct B. pilosicoli genotypes, and common genotypes among herds were rare. B. pilosicoli was re-isolated after 3 years in three herds; the same MRP persisted in each of these herds. A genetic clustering of B. pilosicoli isolates between two major pork production areas was not detected. (+info)
Colonization and risk factors for Brachyspira aalborgi and Brachyspira pilosicoli in humans and dogs on tea estates in Assam, India.
(10/91)
The prevalence of colonization with the anaerobic intestinal spirochaetes Brachyspira aalborgi and Brachyspira pilosicoli was investigated in humans (n = 316) and dogs (n = 101) living on three tea estates in Assam, India. Colonization was detected using PCR on DNA from faeces. Nineteen (6%) human faecal samples contained B. aalborgi DNA, 80 (25.3%) contained B. pilosicoli DNA, and 10 (3.2%) contained DNA from both species. One canine sample contained DNA from B. pilosicoli. Significant factors for B. aalborgi colonization in logistic regression were: infection of family members with B. aalborgi (P < 0.001), being a resident of Balipara (P = 0.03), and use of water treatment (P = 0.03). For B. pilosicoli, significant factors were: other family members being positive for B. pilosicoli (P < 0.001), water obtained from a well (P = 0.006), water treatment (P = 0.03), and not having visited a doctor in the previous 12 months (P = 0.03). (+info)
Brachyspira hyodysenteriae and other strongly beta-haemolytic and indole-positive spirochaetes isolated from mallards (Anas platyrhynchos).
(11/91)
The aims of the current study were to collect intestinal spirochaetes (genus Brachyspira) from farmed and wild mallards (Anas platyrhynchos) and to identify and classify those isolates that phenotypically resembled Brachyspira hyodysenteriae, an enteric pathogen of pigs. The isolation rate of Brachyspira spp. was high from both farmed (93 %) and wild mallards (78 %). In wild mallards, it appeared that Brachyspira spp. were more likely to be found in migratory birds (multivariate analysis: RR = 1.8, 95 % CI 1.1-3.1) than in mallards sampled in a public park. Pure cultures of putative B. hyodysenteriae were obtained from 22 birds. All five isolates from farmed mallards and ten randomly selected isolates with this phenotype were used for further studies. All isolates from farmed mallards and two of the isolates from wild mallards were PCR-positive for the tlyA gene of B. hyodysenteriae. Two isolates from farmed mallards were selected for pulsed field gel electrophoresis (PFGE) and randomly amplified polymorphic DNA (RAPD) analysis. These isolates clustered with the type and reference strains of B. hyodysenteriae. 16S rDNA sequence analysis performed on 11 of the strains showed that they were all closely related to each other and to the B. hyodysenteriae-Brachyspira intermedia cluster. Three of the mallard isolates had 16S rDNA sequences that were identical to those of B. hyodysenteriae strains R1 and NIV-1 previously isolated from common rheas (Rhea americana). To conclude, the isolates from farmed mallards and two isolates from wild mallards were classified as B. hyodysenteriae based on the fact that they could not be differentiated by any of the applied methods from type, reference and field strains of B. hyodysenteriae. The remaining isolates could not be assigned irrefutably to any of the presently recognized Brachyspira species. These results point to a broader host spectrum of B. hyodysenteriae than is generally recognized, and to the presence in mallards of strongly beta-haemolytic and indole-producing spirochaetes that possess many, but not all, of the currently recognized characteristics of B. hyodysenteriae. (+info)
Immunomagnetic separation of the intestinal spirochaetes Brachyspira pilosicoli and Brachyspira hyodysenteriae from porcine faeces.
(12/91)
Porcine intestinal spirochaetes are fastidious anaerobic organisms and, as a consequence, it has been necessary to develop various protocols to enhance their isolation from or detection in faeces. Immunomagnetic separation (IMS) is a method developed recently to improve separation of target cells from mixed cell suspensions. The purpose of the present study was to compare the relative sensitivity of IMS for isolation of Brachyspira pilosicoli and Brachyspira hyodysenteriae with current routine diagnostic methods (culture on selective media and PCR) for detection of these micro-organisms in pig faeces. Neither direct nor indirect IMS methods enhanced the sensitivity of detection of either organism when performed with the recommended washings during sample processing. Performance of the IMS procedure without washing gave sensitivity at levels similar to direct culture onto selective medium. Further development of IMS techniques is required to improve isolation rates of Brachyspira species from faecal samples. (+info)
Extensive intestinal spirochaetosis in pigs challenged with Brachyspira pilosicoli.
(13/91)
A field isolate of Brachyspira pilosicoli, the aetiological agent of porcine intestinal spirochaetosis, was inoculated by stomach tube into six 6-week-old pigs. All animals developed loose to watery faeces and were killed successively on days 8, 14 or 17 post-inoculation (day 17 being the end of the study). Mild mucosal reddening and flecks of pus characterized the gross lesions, while diffuse, catarrhal colitis was revealed microscopically in all animals. Intestinal spirochaetosis with moderate to densely packed end-attached B. pilosicoli organisms was revealed extensively on the mucosal surface of the large intestines by light microscopy and fluorescent in situ hybridization. This study is the first to report extensive intestinal spirochaetosis in pigs challenged with B. pilosicoli. (+info)
Brachyspira pilosicoli colonization in experimentally infected mice can be facilitated by dietary manipulation.
(14/91)
The purpose of this study was to determine whether defined dietary manipulations would enhance colonization of mice experimentally challenged with the intestinal spirochaete Brachyspira pilosicoli. Weanling C3H/HeJ mice (n = 48) were fed either a standard balanced mouse diet or a diet supplemented with 50 p.p.m. zinc bacitracin (ZnB), with 50 % (w/w) lactose or with both supplements. Eight mice from each group were challenged orally with a human strain of B. pilosicoli (WesB), whilst four in each group acted as uninfected controls to evaluate the effects of the diets alone. The mice were kept for 40 days following challenge and faeces were collected every 3-4 days and subjected to culture and PCR for B. pilosicoli. Feeding ZnB reduced total volatile fatty acid production in the caecum. Feeding lactose alone doubled the weight of the caecum and its contents compared with control mice, and resulted in a relatively greater production of acetate, but a reduction in propionate and isovalerate production. These effects were negated by the addition of ZnB with the lactose. None of the mice fed the standard diet or receiving ZnB alone became colonized following experimental challenge. One of the mice receiving lactose was culture and PCR positive for B. pilosicoli on one sampling 1 week after inoculation, and one was positive on three samplings taken 20, 25 and 29 days after inoculation. All mice receiving both lactose and ZnB became colonized and remained so, with all samples being positive over the last seven samplings. The colonization was not associated with an end-on attachment of the spirochaete to the epithelial cells of the caecum, but colonized mice developed a specific humoral antibody response to the spirochaete. (+info)
Biochemical properties of membrane-associated proteases of Brachyspira pilosicoli isolated from humans with intestinal disorders.
(15/91)
A membrane-associated, subtilisin-like, serine protease activity was found in both pathogenic and non-pathogenic strains of Brachyspira species in a previous study, but the biochemical properties of the enzyme were not investigated. The purpose of the present study was to characterize further the biochemical properties, including substrate specificity, of the membrane-associated protease of Brachyspira pilosicoli isolated from humans with intestinal disorders. Protease activity of detergent-enriched membrane protein extracts of B. pilosicoli was assessed using fluorescent dye-labelled synthetic peptides as substrates and determination of electrophoretic mobility of cleavage products in agarose gels. Each activity was further confirmed with class-specific protease inhibitors and thermal denaturation. The presence of a hydrophilic membrane-associated thermolabile serine endopeptidase with specificity for Leu was confirmed. Two additional hydrophilic membrane-associated thermostable proteolytic activities were identified, one with a putative Ala specificity, and one a carboxypeptidase. Taken together, these data suggest that, in addition to a previously described membrane-associated subtilisin-like serine protease, the membrane of B. pilosicoli contains proteins with at least two other proteolytic activities. (+info)
Prevalence, risk factors and molecular epidemiology of Brachyspira pilosicoli in humans on the island of Bali, Indonesia.
(16/91)
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. (+info)